JPH11129414A - Matte finish antistatic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a matte finish antistatic film which shows outstanding antistatic properties and remarkable matte finish and is best suited for various packaging use applications. SOLUTION: This laminated film is formed of layers A, B, C; that is, a matte layer(layer B) with a surface roughness (Rt) of 1-10 μm which is laminated on one the faces of a base layer polypropylene resin layer (layer A) and a low stereoregular polypropylene layer(layer C) with a mesopentad molar fraction of 70-90% which is laminated on the other face of the base layer polypropylene resin layer. The surface glossiness of the layer B is 50% or less and the surface resistance value of the layer C is 10<14> Ω/square or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mat-like antistatic film. More specifically, the present invention relates to a mat-like antistatic film having a matte mat and excellent antistatic properties.

[0002]

2. Description of the Related Art Conventionally, polypropylene films have been widely used for packaging because of their excellent transparency and moisture resistance. In some applications, the texture of paper,
That is, a mat-like film is used. Many of the packaging applications require antistatic properties, and antistatic properties are imparted by adding and mixing an antistatic agent to a polypropylene resin.

However, a two-layer laminated film in which a mat layer is laminated on one side has a problem that the antistatic agent evaporates greatly from the other side in the film forming process and the surface resistance is high. This is because the antistatic agent evaporates during the film-forming process, the concentration of the antistatic agent in the film decreases, and the antistatic agent added to the base layer because the mat layer has a lower crystallinity than the base polypropylene layer. Moves to the mat layer,
It is also considered that the polypropylene resin has a high degree of crystallinity, so that the added antistatic agent does not easily migrate to the surface of the base layer.

Therefore, an extra antistatic agent is added in order to reduce the surface resistance value practically required as a packaging film to 10 ¹⁴ Ω / □ or less, and the amount of transpiration in the film forming process is calculated. The cost is high due to the extra addition. Further, there is a problem that the slip resistance is deteriorated by the extra antistatic agent.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a mat-like antistatic film which has a low evaporation of an antistatic agent and is excellent in antistatic properties.

[0006]

An object of the present invention is to provide a polypropylene resin layer (A layer) as a base layer having a surface roughness (R) on one surface thereof.
t) a mat layer (layer B) having a thickness of 1 to 10 μm is laminated, and the other surface of the layer (A) has a mesopentad fraction of 70 to 90
% Of a low stereoregularity polypropylene layer (C layer) laminated on a layer B / A layer / C layer structure.
The layer has a surface gloss of 50% or less, and the layer C has a surface resistance of 1
It is achieved by a mat-like antistatic film characterized by having a resistivity of 0 ¹⁴ Ω / □ or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene resin (hereinafter abbreviated as PP) layer (A layer) of the base layer of the present invention is usually made of a single polypropylene resin having a mesopentad fraction of 92% or more, or a film of the present invention. Is a mixed resin layer of a polypropylene resin having a mesopentad fraction of 92% or more, a mat layer resin and a low stereoregularity PP in order to self-recover the debris generated in the above step. The mesopentad fraction of the base layer is preferably at least 92%,
It is more preferably at least 94%. By setting the mesopentad fraction of the base layer to 92% or more, the Young's modulus of the film is increased, and the thermal dimensional stability is improved, so that the secondary workability such as slitting, printing, and laminating is excellent. .

The mesopentad fraction of the polypropylene resin in the present invention reflects the stereoregularity of polypropylene. The stereoregularity of the polypropylene film can be evaluated by the pentad fraction due to the absorption of the methyl group measured by ¹³ C-NMR. In general, the conformation of five repeating units (pentads) in a polypropylene molecular chain is mmmm, mmmr, rmm
r, mmrr, mmrm, rmrr, rmrm, rrr
r, mrrr, mrrm, and the like. Here, m is meso, r is racem (racem).
o) shows the conformation. The pentad fraction of the polypropylene film is, for example, T.D. HAYASHHI et al. [P
OLYMER, Vol. 29, 138-143 (198
8)] and the like, the ratio of the segments having each of the above conformations can be determined from ¹³ N-NMR. Among these, the ratio of the conformation of mmmm to the absorption intensity of all methyl groups, that is, the isotactic pentad fraction (hereinafter sometimes abbreviated as mmmm) is m (mmm
m) defined as the sum of three heptad fractions, m, m (mmmm) r, and r (mmmm) r.

Here, the high stereoregularity means that mmmm is 98
% Or more, and low stereoregularity means mmmm
Means 90% or less.

The isotactic index (hereinafter abbreviated as II) of the polypropylene resin layer (A layer) of the base layer
Is preferably 94% or more, and more preferably 96% or more. The melt flow index (hereinafter abbreviated as MFI) is preferably in the range of 1 to 15 g / 10 minutes. By using such a polypropylene resin, the degree of crystallinity of the film is increased, the mechanical properties and the thermal dimensional stability are improved, and the secondary workability is improved.

Next, a mat layer (B) laminated on the base layer
The resin constituting the layer) is preferably a block copolymer of propylene and another olefin resin. Other olefin resins include, for example, polyethylene, polybutene-1, poly4-methyl-pentene-1, propylene / ethylene rubber, propylene / ethylene / diene terpolymer rubber, polybutadiene, polystyrene, polyethylene terephthalate, and the like. The surface of the block copolymer is roughened by stretching, and among these, polyethylene is preferable because a matte tone having a uniform surface roughness can be obtained.

The copolymerization ratio of propylene and olefin is preferably in the range of 95: 5 to 65:35 (% by weight). When a propylene / ethylene block copolymer is used, a block copolymer and a random copolymer can be distinguished by examining the presence or absence of infrared absorption spectra at 720 cm ⁻¹ and 731 cm ⁻¹ . Those absorption of 720 cm ^-1 is attributed to ethylene, the absorption of 731cm ^-1 but is due to propylene chain, both absorption appears in practice.

[0013] The block copolymers suitable for the present invention the ratio A / B of the absorbance B of absorbance A and 731cm ^-1 of 720 cm ^-1 is preferably in the range of 0.4 to 3.0, more preferably 0. It is in the range of 6 to 2.0. 0.4-3.
By setting the range to 0, the matting effect becomes excellent.

Further, inorganic particles may be added to the above-mentioned block copolymer. Examples of the inorganic particles include calcium carbonate, magnesium carbonate, magnesium oxide, alumina, silica, aluminum silicate, kaolin, kaolinite, talc, clay, diatomaceous earth, montmorillonite, titanium oxide, and zeolite. The average particle size of these inorganic particles is preferably 0.1 to 5 μm, more preferably 0.2 to 2 μm, and the amount added is 1 to 20% based on the polymer.
Is more preferable, and more preferably in the range of 5 to 15%.
The surface roughness (Rt) of the B layer is the maximum protrusion height (hereinafter abbreviated as Rt) measured by the stylus method, and Rt is 1 to 10 μm.
m. If Rt is less than 1 μm, the glossiness increases and the matting effect deteriorates, resulting in loss of aesthetic appearance. If Rt exceeds 10 μm, projections are scraped off during film formation or during secondary processing, causing white powder or slitting the film. It is not preferable because it causes a winding deviation when winding into a long length.

The layer thickness of the layer B is preferably at least 0.5 μm, more preferably at least 1 μm, and preferably less than 1/3 of the total thickness of the laminated film. B
When the layer thickness is 0.5 μm or more, a uniform mat layer can be obtained and the texture of the paper can be improved. Further, it is preferable that the layer thickness of the layer B is less than 1/3 of the thickness of the entire laminated film in order to prevent a decrease in the Young's modulus of the film and a decrease in the secondary workability.

Next, the mesopentad fraction of the low stereoregularity PP layer (C layer) laminated on the base layer (A layer) is 70-90.
%, Preferably 75 to 8%.
It is in the range of 8%. By controlling the amount within this range, the evaporation of the antistatic agent and the lubricant in the extrusion or film forming process is suppressed, and the crystallinity of the surface layer portion is suppressed, and the expression of the antistatic agent is improved by corona discharge treatment after film formation. Becomes

If the meso pentad fraction of the C layer is less than 70%, the sliding property is poor, and the sliding property with the metal roll during film formation or during secondary processing is poor, and abrasion is caused. When the mesopentad fraction exceeds 90%, the migration of the antistatic agent and the lubricant added to the layer A to the surface layer is small, and the bleedout promoting effect of the antistatic agent by the corona discharge treatment is reduced, and the antistatic property is deteriorated. I do.

The mesopentad fraction is 70-90%.
Low stereoregularity PP means that the mesopentad fraction is 70 to
90% PP alone and 2 with different mesopentad fractions
It is preferably a mixed resin with at least one kind of PP. Further, a resin in which a small amount of another α-olefin resin is added or copolymerized to such an extent that the film characteristics are not deteriorated may be used.

Further, it is preferable that the melting point (hereinafter abbreviated as Tm) of the low stereoregularity PP is 155 ° C. or more and the crystallization temperature (hereinafter abbreviated as Tmc) is 100 ° C. or more. If the Tm is less than 155 ° C., the blocking shear force becomes high, and the film may be broken when the film wound up in a roll is unwound at a high speed. Further, when Tmc is less than 100 ° C., at the time of high-speed film formation at a film formation speed of 150 m / min or more, the film surface is not completely crystallized between the winder and the exit of the tenter after the transverse stretching, and the film is transferred to the metal roll of the winder. Stickiness is easy to occur.

It is preferable that an antistatic agent and a lubricant are not added to the layer C in advance, and the antistatic agent and the lubricant added to the layer A are transferred to the layer C in an extrusion or film forming step, thereby exhibiting an antistatic property. By doing so, evaporation of the antistatic agent and the lubricant during the film forming process can be suppressed.

The layer thickness of the layer C is preferably 0.2 μm or more, more preferably 0.5 μm or more, and preferably less than １ ／ of the total laminated film thickness. When the layer thickness of the layer C is 0.2 μm or more, the evaporation of the antistatic agent and the lubricant added to the base layer (layer A) in the extrusion and film forming steps can be sufficiently suppressed. Further, it is preferable that the layer thickness of the layer C is less than 1/3 of the thickness of the entire laminated film, so that the antistatic agent and the lubricant added to the layer A are transferred to the surface layer to improve the antistatic property and the slipperiness. It is also preferable because it also prevents a decrease in Young's modulus and a decrease in secondary workability.

The layer C has a resin composition in which the antistatic agent and the lubricant added to the layer A are transferred during the extrusion and film forming steps, and are mixed with inorganic particles and / or crosslinked organic particles for imparting lubricity. Is preferred.

The antistatic agent contained in the layer A, the layer C and / or the layer B is not particularly limited.
Examples thereof include an ethylene oxide adduct of a betaine derivative, a quaternary amine compound, an alkyldiethanolamine fatty acid ester, a glycerin fatty acid ester, stearic acid monoglyceride, and stearic acid diglyceride, and a mixture thereof.

The lubricant is added in order to improve the fluidity and mold releasability of a thermoplastic resin expressed in JIS terms during heat molding.
Alternatively, it is added to adjust the frictional force between the films. For example, amide compounds such as stearic acid amide, erucic acid amide, erucic acid amide, and oleic acid amide, and the like, or a mixture thereof can be used.

The content of the antistatic agent and the lubricant in the present film is preferably from 0.3 to 2.0% by weight, more preferably from 0.5 to 1.0% by weight. Within this range, the antistatic property and the slip property are excellent.

The inorganic particles added to the film of the present invention are inorganic particles of a metal compound, and the crosslinked organic particles are particles obtained by crosslinking a polymer compound with a crosslinking agent. Crosslinked particles of a polymethoxysilane compound, crosslinked particles of a polystyrene compound, crosslinked particles of an acrylic acid compound, crosslinked particles of a polyurethane compound, crosslinked particles of a polyester compound, crosslinked particles of a fluorine compound, or a mixture thereof. Can be mentioned.
Among them, particularly, cross-linked particles of a polymethacrylate compound (hereinafter sometimes abbreviated as cross-linked PMMA particles) and polypropylene resin are preferred because of their good affinity.

The average particle size of the inorganic particles and the crosslinked organic particles is preferably in the range of 0.5 to 6 μm. The average particle size is 0.
When the thickness is 5 μm or more, the slipperiness is improved, and when the thickness is 6 μm or less, it is possible to prevent the particles from falling off and the film surface from being easily damaged when the films are rubbed. The addition amount of the inorganic particles and / or the crosslinked organic particles is
The content is preferably in the range of 0.02% by weight to 0.5% by weight, and more preferably 0.05% by weight to 0.2% by weight, from the viewpoint of anti-blocking property and slipperiness.

The layer A, layer B,
If necessary, a small amount of a nucleating agent other than the above, a heat stabilizer, an antioxidant, etc. may be added to all or a part of the layer C. For example, as a nucleating agent, a sorbitol-based nucleating agent, an organic phosphate metal salt-based nucleating agent, or the like is used.
2% by weight or less, 2,6-di-tert-butyl-4-methylphenol (BHT) or the like as a heat stabilizer 0.5% by weight or less, and as an antioxidant tetrakis- (methylene-
(3,5-di-tert-butyl-4-hydroxy-hydroxycinnamate)) butane ("Irganox" 1
010) may be added at 0.5% by weight or less.

Next, the surface of the layer B and / or C of the film of the present invention is subjected to a corona discharge treatment to increase the wetting tension of the film surface to 35 mN / m or more.
It can be preferably employed to improve the bleed-out property of the adhesive, the antistatic agent and the lubricant. Atmosphere gases during corona discharge treatment at this time include oxygen, air,
Carbon dioxide or a mixed system of nitrogen / carbon dioxide is preferred, and it is particularly preferred to perform corona discharge treatment in air in terms of economy.

The surface resistance of the C layer of the present invention is 10 ¹⁴ Ω / □.
Or less, and more preferably 10 ¹³ Ω / □ or less. If the surface resistance value exceeds 10 ¹⁴ Ω / □, dust adheres, and when the films are formed and stacked, the bags are displaced or adhered, resulting in poor handleability, and in the case of bag-made products. When packing the contents, there is a problem that the contents adhere to the bag.

The glossiness of the film surface representing the matte tone of the film of the present invention needs to be 50% or less,
Preferably it is 40% or less. If the gloss exceeds 50%, the appearance as a matte film becomes poor, and the commercial value decreases.

The film of the present invention may be any of a non-stretched film, a uniaxially stretched film and a biaxially stretched film, but is preferably a biaxially stretched film from the viewpoint of protecting the contents of a bag-formed product. .

Next, the method for producing the film of the present invention will be described by way of an example, but it goes without saying that the present invention is not limited to this example.

First, an antistatic agent and a lubricant were added to a mixed resin of a polypropylene resin having a mesopentad fraction of 92% or more as a base layer (A layer) resin and a self-recovered flake generated in the production of the film of the present invention, and an extruder. Supply to
The mixture is melted and mixed at a temperature of 280 ° C., and as a mat layer (B layer) resin, 10 to 30% by weight of a high density polyethylene having a density of 0.93 or more is added to a propylene / ethylene block copolymer having an ethylene component of 3%. At a temperature of 270 ° C., and as a low stereoregularity PP layer (C layer) resin, a mesopentad fraction substantially not containing an antistatic agent and a lubricant is 70 to 90%, and a melting point is 155 ° C. As described above, the inorganic particles and / or the crosslinked organic particles are added to PP having a crystallization temperature of 100 ° C. or higher, and are supplied to another extruder, melt-mixed at a temperature of 260 ° C., and after each passing through a filter, B-layer / A with slit-shaped three-layer laminated base
Layer / C layer was co-extruded and laminated to form a film, and the film was wound around a metal drum kept at 30 to 70 ° C. and cooled and solidified to obtain an unstretched laminated film.

Next, the unstretched laminated film is placed in a
Pre-heated by passing through a roll maintained at 140 ° C., then passed through a roll provided with a peripheral speed difference while maintaining the laminated film at 120 to 150 ° C., stretched 4 to 7 times in the longitudinal direction, and immediately cooled to room temperature I do. Subsequently, the stretched film was guided to a tenter and preheated at a temperature of 160 ° C. or more.
The film was stretched 5 times or more in the width direction at a temperature of 0 ° C. or more, and then heat-set at a temperature of 160 ° C. or more while giving a relaxation of 2% or more in the width direction to obtain a biaxially stretched laminated film. The preheating and the stretching temperature during the transverse stretching are 1
Preferably it is 60 ° C. or higher. Next, the biaxially stretched laminated film was passed through a roll maintained at 30 ° C. or higher, and 15 W
The surface of the layer B and / or layer C is subjected to corona discharge treatment at a speed of not less than min / m ² and wound up.

The film of the present invention can be used after embossing, printing, vapor deposition, extrusion lamination, and laminating with another resin film, paper, cloth, or the like according to the purpose.

[0037]

[Method of measuring characteristic values] The characteristic values of the present invention are determined by the following measuring methods.

(1) Mesopentad fraction (mmmm) A sample was dissolved in o-dichlorobenzene, and JN
Using an M-GX270 device, a resonance frequency of 67.93 MH
The ¹³ C-NMR was measured at z. For the assignment of the obtained spectra and the calculation of the pentad fraction, see T.W. Hay
, et al. [Polymer, 29, 13]
8 to 143 (1988)], the peak derived from the methyl group had a mmmm peak of 21.855 ppm.
The peak area was determined, the peak area was determined, and the ratio to the total peak area derived from the methyl group was expressed as a percentage. Detailed measurement conditions are as follows.

Measurement solvent: o-dichlorobenzene (90 w
t%) / benzene-D ₆ (10 Wt%) Sample concentration: 15 to 20 wt% Measurement temperature: 120 to 130 ° C. Resonance frequency: 67.93 MHz Pulse width: 10 μsec (45 ° pulse) Pulse repetition time: 7.091 sec Data points : 32K Number of times of accumulation: 8168 Measurement mode: Noise decoupling For the laminated film, the surface layer is peeled off or scraped off, and the measurement is performed by the same method as described above.

(2) Isotactic index (I
I) Vacuum dry the sample at 130 ° C for 2 hours. Thereafter, the temperature is returned to room temperature, and a sample having a weight of W (mg) is taken therefrom, placed in a Soxhlet extractor, and extracted with boiling n-heptane for 12 hours.
Next, the sample was taken out and sufficiently washed with acetone.
After drying at 30 ° C. for 6 hours, the weight W ′ (mg) is measured at room temperature and determined by the following equation.

II = (W '/ W) × 100 (%)

(3) Melt flow index (MF)
I) Polypropylene test method according to JIS K-6758 (23
0 ° C, 2.16 kgf).

(4) Lamination Thickness and Average Particle Diameter The cross-sectional structure of the film was observed using an electrolytic emission scanning electron microscope (FE-SEM) to measure each lamination thickness and the average particle diameter of the particles. As the average particle diameter of the particles in the film, the major axis of 100 particles observed by FE-SEM was measured, and the average value was defined as the average particle diameter.

(5) Surface Roughness (Rt) As described in JIS B 0601-1976, it is represented by the maximum protrusion height Rt measured by the stylus method.

(6) Gloss The gloss was measured according to ASTM-D-2457.

(7) Wetting tension on film surface Measured according to the method of JIS K-6768.

(8) Content of Antistatic Agent and Lubricant in Laminated Film Secondary ion mass spectrometer (A-TOMIKA, Germany)
Using DIDA3000), analysis of the laminated film of the elements contained in the antistatic agent and the organic lubricant in the thickness direction was performed.

(9) Surface resistance GIGAOHMMETR-VE40 and RESISTI manufactured by KAWAGUCHI ELECTRIC WORKS
Using VITY CHAMBRE-P601, temperature 2
It was determined by measuring in an atmosphere at 3 ° C. and a humidity of 63%.

(10) Slip property The static friction coefficient when both surfaces of the film were overlapped and rubbed was measured according to ASTM-D 1894-63, and the coefficient of static friction (μs) was in the range of 0.2 to 0.7. It is excellent in winding property and secondary workability, and it is evaluated as ○. If it is less than 0.2, it causes winding deviation, and if it is 1.0 or more, wrinkles occur during winding and secondary processing due to poor slipperiness, and it is ×. The middle was evaluated as △.

(11) Young's modulus of film The film wound into a roll is cut into a 10 mm-width strip, and the length is measured to 50 mm, and the film is mounted on a Tensilon (manufactured by Toyo Sokki). A rising curve is recorded on chart paper at a chart speed of 500 m / min. After drawing a tangent to the rising curve from the base point of the chart paper, a perpendicular line is drawn at a point 25 mm from the base point, and the intersection of the tangent line and the perpendicular line is read as strong. Then, the Young's modulus (GPa) is calculated by the following equation.

Young's modulus (GPa) = [Strength (kg) × Test length (mm) × Chart speed (mm / min)] ÷ [Tensile speed (mm / min) × 25 mm × Film thickness (m
m) × film width (mm)] × 9.807 × 10 ⁻³

(12) Melting point (Tm), crystallization temperature (Tm)
c), heat of crystal fusion (ΔHu) When using a robot DSC (differential scanning calorimeter) RDC220 manufactured by Seiko Denshi Kogyo Co., Ltd., 5 mg of a sample was heated from room temperature at a heating rate of 20 ° C./min. The apex of the endothermic peak accompanying the melting was defined as the melting point (Tm), and the heat of crystal fusion (ΔHu) was determined from the area. This area is shifted from the baseline to the endothermic side by increasing the temperature, and is the area until the temperature returns to the baseline position when the temperature is further increased.A straight line connects the melting start temperature position to the end temperature position. The area was determined by computer processing. When a plurality of endothermic peaks are observed, the sum of the peaks is defined as the heat of crystal fusion. Then, the temperature was raised to a melting holding temperature of 280 ° C., and after holding for 5 minutes and then cooling at a cooling rate of 20 ° C./min, a latent heat peak temperature accompanying crystallization was defined as a crystallization temperature (Tmc). .

(13) Secondary workability When a non-stretched polypropylene film having a thickness of 25 μm is laminated as a heat seal layer on the opposite side of the mat layer of the film, and a film having a length of 1000 m is applied to a bag making machine,
No white powder was generated due to the film surface scraping, wrinkles were not generated, and the shape of the bag-making product was good, and white powder was generated due to the film surface scraping, the Young's modulus was low, and the slipperiness was poor. For this reason, the wrinkles were formed and the shape of the bag-making product was deteriorated.

The present invention will be described with reference to examples.

Example 1 A resin having a mesopentad fraction (hereinafter abbreviated as mmmm) of 97% (II = 96.5) was used as the base layer (layer A) resin of the present invention.
%, MFI = 2.0 g / 10 min) in a mixed resin of a self-recovered flake generated in the production of the film of the present invention and a glycerin fatty acid ester and an alkyldiethanolamine fatty acid ester in a ratio of 1: 1. And then added to the extruder and melt-mixed at a temperature of 280 ° C. Then, as a mat layer (B layer) resin, a propylene / ethylene block copolymer having an ethylene component of 13% is used. Has a density of 0.932.
20% by weight of high-density polyethylene
The mixture was melted and mixed at a temperature of ℃, and as a low stereoregularity polypropylene layer (C layer) resin, the mmmm without substantially adding an antistatic agent and a lubricant was 74%, and the melting point was 161.
° C and a crystallization temperature of 110 ° C polypropylene resin (II
= 88%, MFI = 3.2 g / 10 min), 0.15% by weight of crosslinked particles of a polymethacrylic acid polymer (crosslinked PMMA) having a particle size of 1 μm as crosslinked organic particles was added and supplied to an extruder. The mixture was melt-mixed at a temperature of 260 ° C., passed through a filtration filter, and then co-extruded and laminated with a slit-shaped three-layer lamination die in a thickness configuration of B layer / A layer / C layer = 2/17/1 to form a film. The film is wound around a metal drum maintained at 60 ° C. and solidified by cooling, and the thickness is 950 μm.
Was obtained.

Next, the unstretched laminated film was heated at 130 ° C.
Preheated by passing through rolls kept at, and then passed between rolls provided with a peripheral speed difference while keeping the laminated film at 140 ° C.
The film is stretched 4.75 times in the machine direction and immediately cooled to room temperature. Subsequently, the stretched film was guided to a tenter, and 17
It is preheated at a temperature of 0 ° C., stretched 10 times in the width direction at a temperature of 160 ° C., and then heat-set at a temperature of 160 ° C. while giving a relaxation of 8% or more in the width direction to form a 20 μm thick An axially stretched laminated film was obtained. Next, the biaxially stretched laminated film is passed through a roll maintained at 40 ° C., and is subjected to 15 W ·
Both surfaces were subjected to a corona discharge treatment at a rate of min / m ² and wound up.
Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics.

The resulting film has a low matte layer gloss and a sober and calm surface effect, and the B and C layers contain an antistatic agent, and have a low surface resistance and have an antistatic property. It was a mat-like antistatic film having excellent properties, excellent slipperiness, and excellent secondary workability.

Example 2 As a resin of the mat layer (layer B) of the present invention, styrene component 1
As a 5% by weight propylene-styrene block copolymer resin body, and as a low stereoregularity polypropylene layer (C layer), mmmm is 85%, melting point (Tm) is 160 ° C, and crystallization temperature (Tmc) is 105 ° C. 0.12% by weight of crosslinked polystyrene-based polymer particles (crosslinked PS) having a particle size of 2 μm as crosslinked organic particles were added to a polypropylene resin (II = 88%, MFI = 1.8 g / 10 minutes), and each was separated. And melted at 270 ° C. Next, as a resin composition of the base layer (layer A), a polypropylene resin having a mmmm of 98.5% (II = 98%, MFI = 2.2 g)
/ 10 minutes), 0.55% by weight of a betaine-type antistatic agent and 0.15% by weight of oleamide were added and mixed.
After feeding to another single-screw extruder and melting at 270 ° C., each of them was passed through a filtration filter, and then, with a three-layer forming die, the thickness constitution B layer / A layer / C layer = 2/13/1. And then extruded into a sheet at 50 ° C
And cooled to obtain a 750 μm thick sheet.

Next, the sheet is preheated by passing through a roll maintained at 135 ° C. Then, the sheet is passed through a roll having a peripheral speed difference maintained at 140 ° C. and stretched 5.0 times in the longitudinal direction. Cool immediately to room temperature. Subsequently, the stretched film is guided to a tenter and preheated at a temperature of 175 ° C.
Subsequently, the film was stretched 10 times in the width direction at 170 ° C., and then heat-set at a temperature of 165 ° C. while giving 8% relaxation in the width direction to obtain a biaxially stretched laminated film having a thickness of 15 μm. Next, the biaxially stretched film was passed through a roll maintained at 50 ° C., wound on a corona discharge treatment on both sides at 25 W · min / m ² in air. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics.

The obtained film has a low matte layer gloss and a sober and calm surface effect, and contains an antistatic agent in the B and C layers, and has a low surface resistance and thus has an antistatic effect. It was a mat-like antistatic film having excellent properties, excellent slipperiness, and excellent secondary workability.

Example 3 As the resin for the base layer (layer A) of the present invention, mmmm was 98% (I
Glycerin fatty acid ester and alkyldiethanolamine fatty acid ester as antistatic agents to a mixed resin of a polypropylene resin (I = 98.5%, MFI = 2.0 g / 10 min) and a self-recovered flake generated in the production of the film of the present invention. 0.6% by weight mixed in 1: 1 ratio
The mixture is supplied to an extruder and melt-mixed at a temperature of 280 ° C. Then, as a mat layer (layer B) resin, ethylene component 1
10% by weight of calcium carbonate having an average particle size of 2 μm was added to 3% of a propylene / ethylene block copolymer and mixed.
The resin is melt-mixed at a temperature of 70 ° C., and as a low stereoregularity polypropylene layer (C layer) resin, the mmmm is 78% substantially without adding an antistatic agent and a lubricant, and the melting point is 16%.
0 ° C., crystallization temperature of 109 ° C. polypropylene resin (I
I = 86%, MFI = 2.5 g / 10 min), 0.15% by weight of crosslinked particles of a polymethacrylic acid polymer (crosslinked PMMA) having a particle size of 2 μm as crosslinked organic particles was added and supplied to an extruder. The mixture was melt-mixed at a temperature of 260 ° C., passed through a filtration filter, and then co-extruded and laminated with a slit-shaped three-layer lamination die in a thickness configuration of B layer / A layer / C layer = 2/17/1. It is formed into a film, and the film is wound around a metal drum kept at 30 ° C., cooled and solidified, and has a thickness of 950 μm.
m, and a biaxially stretched film having a thickness of 20 μm was obtained in the same manner as in Example 1 except that a non-stretched laminated film of m was obtained. Corona discharge treatment was performed in the same manner as in Example 1. Table 1 shows the film composition and structure at this time, and Table 2 shows the film quality characteristics.
It was shown to. The resulting film has a matte layer with low gloss and a sober and calm surface effect, and contains an antistatic agent in layers B and C, and has a low surface resistance and excellent antistatic properties. Further, it was a mat-like antistatic film which was excellent in slipperiness and also excellent in secondary workability.

Example 4 As the low stereoregularity polypropylene layer (C layer) of the present invention, a polypropylene resin having a mmmm of 74% and a polypropylene resin having a mmmm of 91% (II = 97)
%, MFI = 2.0 g / 10 min), and a biaxially stretched film was obtained in the same manner as in Example 1 except that a mixed resin having a mixing ratio of 1: 2 and an apparent mesopentad fraction of 85% were used. . Corona discharge treatment was performed in the same manner as in Example 1.
Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. The resulting film has a matte layer with low gloss and a sober and calm surface effect, and contains an antistatic agent in layers B and C, and has a low surface resistance and excellent antistatic properties. , Also excellent in slipperiness,
Further, it was a mat-like antistatic film excellent in secondary workability.

Comparative Example 1 In Example 1, a low stereoregularity polypropylene layer (C
A film having a thickness of 20 μm was obtained in the same manner as in Example 1 except that a two-layer film having a resin composition of a base layer (layer A) and a mat layer (layer B) was not laminated. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. The resulting film has a low antistatic agent content in the film due to a large amount of evaporation of the antistatic agent during film formation,
Further, a large amount of the antistatic agent migrated to the mat layer, the surface resistance of the surface of the layer A was high, the antistatic property was poor, and the film was poor in slipperiness and poor in secondary workability. .

Comparative Example 2 As the mat layer (layer B) of Example 1, an ethylene component of 3.
7% propylene / ethylene random copolymer with particle size 2
μm silicon oxide 0.1% by weight is added to the resin composition,
Mmm as low stereoregularity polypropylene layer (C layer)
m is 95%, melting point (Tm) is 162 ° C., and crystallization temperature (Tmc) is 110 ° C. polypropylene resin (II = 9)
7%, MFI = 2.0 g / 10 min) and 0.05 wt% of crosslinked polystyrene particles having a particle size of 2 μm as crosslinked organic particles.
%, And a biaxially stretched film was obtained in the same manner as in Example 1 except that the resin composition was added. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. The resulting film had a surface roughness (R) of the mat layer (B layer).
t) is small, does not have a matte tone due to high gloss, and has a high mesopentad fraction of the C layer, so that the film exhibits poor antistatic properties, high surface resistance, and poor antistatic performance. Met.

Comparative Example 3 As a low stereoregularity polypropylene layer (C layer), mmm
m is 65%, melting point (Tm) is 149 ° C., and crystallization temperature (Tmc) is 93 ° C. polypropylene resin (II = 90)
%, MFI = 5.8 g / 10 min), and a biaxially stretched film was obtained in the same manner as in Example 1. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. The obtained film has a low surface resistance value of the C layer and is excellent in antistatic properties. However, because the mmmm is too low, the melting point and the crystallization temperature are low, the coefficient of static friction is large, and the slip property is poor. The film was inferior in the next processability.

Comparative Example 4 As a mat layer (layer B) resin, a propylene / ethylene block copolymer having an ethylene component of 13% was added to a resin having an average particle size of 4 μm.
A film was obtained in the same manner as in Example 3, except that the resin composition was mixed with 30 m% of calcium carbonate. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. In the obtained film, the surface roughness (Rt) of the mat layer (B layer) becomes too large, which causes a winding deviation when the film is slit and wound into a long length. The protrusions were scraped off inside to produce white powder.

Comparative Example 5 In Example 2, the thickness of the film was changed to B layer / A layer / C layer = 5/5 with the lamination thickness of the surface layer (B layer) being 5 μm.
A film was obtained in the same manner as in Example 2 except that the thickness was changed to / 5 μm. Table 1 shows the film composition and constitution at this time, and Table 2 shows the film quality characteristics. The resulting film is
Since the layer B and the layer C had a large lamination thickness, the antistatic agent concentration on the film surface was low, the surface resistance was high, and the film was poor in secondary workability.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

The film of the present invention has a surface roughness (Rt) of 1 to 1 on one surface of the base polypropylene resin layer (layer A).
B layer / A layer / a layer in which a mat layer (B layer) of 0 μm is provided, and a low stereoregular polypropylene layer (C layer) having a mesopentad fraction of 70 to 90% is provided on the other surface of the (A layer). C
A film constituting the layer, wherein the surface glossiness of the layer B is 50
% Or less, and the surface resistance of the C layer is 10 ¹⁴ Ω / □ or less, so that the matte layer has a low glossiness and a calm and calm surface effect is obtained. Thus, it was possible to provide a mat-like antistatic film suitable for various packaging applications, having excellent antistatic properties, excellent slipperiness, and excellent secondary workability.

Claims (6)

[Claims] 1. A mat layer (B) having a surface roughness (Rt) of 1 to 10 μm on one surface of a polypropylene resin layer (A layer) as a base layer.
Layer), and a low stereoregularity polypropylene layer (C) having a mesopentad fraction of 70 to 90% on the other surface of the layer A.
Layer B), a laminated film having a B layer / A layer / C layer configuration, wherein the surface gloss of the B layer is 50% or less and the surface resistance value of the C layer is 10 ¹⁴ Ω / □ or less. Characteristic matte antistatic film. 2. The mat-like antistatic film according to claim 1, wherein the resin constituting the mat layer (B layer) is a block copolymer of propylene and another olefin resin. 3. The laminated thickness of the mat layer (layer B) is 0.5 μm.
The mat-like antistatic film according to claim 1 or 2, wherein the thickness is less than 1/3 of the total thickness of the laminated film. 4. A low stereoregularity polypropylene layer (C layer)
Is a mixed resin of two or more types of polypropylene resins having different mesopentad fractions.
4. The mat-like antistatic film according to any one of claims 1 to 3. 5. The method according to claim 1, wherein an antistatic agent is added to at least the polypropylene resin layer (A layer) of the base layer, and inorganic particles and / or crosslinked organic particles are added to the low stereoregular polypropylene layer (C layer). The mat-like antistatic film according to any one of claims 1 to 4. 6. The laminate according to claim 1, wherein the laminated thickness of the low stereoregularity polypropylene layer (C layer) is 0.2 μm or more, and the total thickness is less than １ ／ of the total laminated film thickness. 6. The matte antistatic film according to 5.