JPS6088049A - Biaxially oriented polypropylene film - Google Patents

Abstract

PURPOSE:The titled film having excellent transparency, slipperiness, and blocking resistance, obtained by molding a resin composition, consisting of a specified crystalline PP, nucleator, and Si compound, in the form of a film. CONSTITUTION:0.01-1.0pts.wt. nucleator (e.g. sodium adipate), and 0.05-2.0pts. wt. inorganic or organic Si compound having an average diameter of 0.2-5.0mu (e.g. synthetic zeolite) are incorporated into 100pts.wt. crystalline PP, having an intrinsic viscosity [eta] of tetralin solution at 135 deg.C of 1.0-2.0, an isotactic index of at least 98%, to obtain the resin composition. Then, the composition is molded in the form of a film, which is stretched biaxially, 3-7 times longitudinally and 5-15 times transversely, producing a biaxially oriented PP film having a gloss value of at least 145 and a thickness of 5-150mu.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to biaxially oriented polypropylene films.

[Conventional technology]

As a conventional biaxially oriented polypropylene film, one in which a nucleating agent is added to ordinary polypropylene to improve transparency is known. However, this film did not significantly improve gloss and was poor in lubricity and anti-blocking properties, necessitating the addition of an organic lubricant (eg fatty acid amide) or an inorganic lubricant.

[Purpose of the invention]

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a biaxially oriented polypropylene film which has a gloss level of 145 or more, has excellent transparency, is easy to slip, and is difficult to scratch/print.

[Structure of the invention]

In order to achieve the above object, the present invention has the following configuration, namely:
Intrinsic viscosity [v) 1.0-20. Intactic degree 98
% or more of crystalline polypropylene, 0.01 to 1.0 parts by weight of a nucleating agent, and 0.05 to 1.0 parts by weight of a silicon compound.
It is a biaxially oriented polypropylene/film 't4I containing 2O7JL edge part and having a gloss level of 145 or more.

In the present invention, crystalline polypropylene means 165°C
The intrinsic viscosity [η] in a tetralin solution is in the range of 10 to 2.0, preferably in the range of 1.1 to 1.95, and is 100% of the residue after extraction with boiling n-hebutane for 12 hours. (
A propylene polymer with an isotactic degree of 98 degrees or higher. Crystalline polypropylene pellet [η] whose intrinsic viscosity [η] of biaxially oriented polypropylene falls within the range of the present invention
It is necessary that [η] be in the range of 11 to 2.1 in view of the decrease in thermal integrity, but it is preferable that [η] of the crystalline polypropylene pellet be in the range of 12 to 20.

However, it is essential that the degree of isotacticity satisfies the scope of the present invention.

In order for [η] at the pellet stage to be within the range mentioned here, it must be regulated to be within this range for one polymerization stage.

Although crystalline polypropylene can be obtained, the high [η
] The crystalline polypropylene of [η
] It is possible to obtain crystalline polypropylene in the range of . The latter may be preferred in stretching.

In the present invention, those whose intrinsic viscosity [η] is outside the above range are difficult to stretch, and those whose glossiness is less than 98 nl) are considered glossy.

The transparency becomes low and inferior, and it is difficult to achieve high gloss and excellent transparency.

A nucleating agent is a substance that acts as a nucleus for a crystal and is effective in growing the crystal.Specifically, it includes sodium adiphate, sodium benzoate, aluminum adipate, aluminum tertiary benzoate, and aluminum benzoate. , dibenzyritene rubitol and its derivatives are desirable.

The amount of the nucleating agent added is 0.001 to 1.0 parts by weight, preferably 0.02 to 1.0 parts by weight, based on 100 parts by weight of the crystalline polypropylene.
If the amount is less than 414 N, the effect of the nucleating agent will be small, and if it exceeds this range, it will ooze out from the film surface, transfer to rolls etc. during the film manufacturing process, and cause the film to deteriorate. It stains the surface and reduces transparency and gloss.

The silicon compound refers to inorganic and organic silicon compounds.

Inorganic silicon compounds include silicon dioxide, aluminum silicate, aluminum silicate soda, etc., specifically thyroid, silica, mica, curcum, diatomaceous earth, kaolin, kaolinite, bentonite, natural zeolite, synthetic zeolite. These substances play the role of lubricants. The preferred average particle size is 0.2 to 5.0
μ.

Silicone oil is cited as an organic silicon compound. The viscosity is 40 to 4[1,0[l[l] centistokes (25°C), and specifically, it is one of methylethylpolysiloxane, methylhydrodievorisiloxane, dimethylpolysiloxane, and dimethylborisiloxane. Modified silicone oil with other organic groups introduced into the methyl group,
Examples of these include amide 7 groups, carboxyl groups, polyoxyalkylene groups, long-chain alkyl groups, and epoxy groups.

Among these, dimethylpolysiloxane, polyoxyalkylene-modified polysiloxane, long-chain alkyl-modified polysiloxane, etc. or a mixture thereof are preferred.

Smoothness, anti-blocking properties, and even anti-blocking properties can be imparted in some cases.

The amount added is 0.05 to 20 parts by weight, more preferably 1 to 7100 parts by weight of the crystalline polypropylene.
One amount ranges from 0.07 to 10 parts by weight. If the amount is less than 005, the slipping properties and blocking resistance will be poor, and if it exceeds 20 parts by weight.

The gloss level decreases and the transparency becomes inferior.

Although inorganic and organic silicon compounds may be added in combination, the amount added is within the scope of the present invention.

In addition, to identify silicon compounds, it is determined that they contain silicon by 9 emission spectroscopy or absorption spectroscopy, and the ash content of one film (by heating and ashing at 850'O in air and measuring the percentage of ash content) is determined. , when the ash content is in the range of 0.045 to 1.8 wt%, the silicon compound is
It is determined that it is within 14.

In addition, since it has a gloss level (AS-60) of 145 or more, it can be used for high-grade and special purposes such as glitter laminating films, release films, adhesive films, packaging materials, etc.

The biaxially oriented polypropylene film of the present invention is.

Either sequential stretching or simultaneous stretching may be used. The stretching ratio is preferably 6 to 7 times in the longitudinal direction and 5 to 15 times in the transverse direction.

Although the film thickness is not particularly limited, 5 to 150 μm is preferably used.

Crystalline polypropylene contains stabilizers, antioxidants,
Ultraviolet absorbers, weathering agents, antistatic agents, colorants, brighteners, etc. may be added.

The characteristic values of the present invention are determined by the following measurement method.

(1) Intrinsic viscosity [η] Measure the relative viscosity in a 1-5'O tetralin solution.

Calculate the intrinsic viscosity [η].

(2) Isotactic degree (technical, technical) refers to the percentage of the weight of the residue after extraction with boiling n-hebutane for 12 hours based on the weight before extraction. however.

The weight before extraction refers to the value excluding additives such as nucleating agents.

(3) Glossiness This refers to the value according to Method 2 of J Engineering S-28741, and the higher the value, the better the glossiness.

(4) Haze (Evaluation of Transparency) 9.8 sheets were measured using 6714 on J-Ko S-Haze means the value measured by stacking 8 sheets. A low haze value means excellent transparency.

(5) Sliding coefficient: Two samples were conditioned for 24 hours in a room with a humidity of 20°C and 65% RH.The opposite sides of the two samples were stacked on top of each other, and a 200g load was placed on top of the two samples. The resistance value was read while moving at a speed of 1/min, and was expressed as a calculated value of resistance value (g)/2DDg.

(6) Blocking shear force (evaluation of surface 1 blocking property) A sample film of width 3 cm x length 10 cn1 was
After being stacked for 24 hours under a load of 40 g 7 cm ° in an atmosphere of 40 ° 0, 80% RH.

The force required for shear peeling is determined using a tensile tester.

The smaller the value, the better the rigid blocking property.

〔Effect of the invention〕

As described above, the present invention is a biaxially oriented polypropylene film in which a specific amount of a nucleating agent and a silicon compound are added to specific crystalline polypropylene.

We were able to create a film with a gloss level of 145 or higher, excellent transparency, and satisfactory lubricity and anti-blocking properties.

The biaxially oriented polypropylene film of the present invention is.

For print lamination (attaching to printed materials).

This film is suitable for high-grade and special uses such as #-type applications, packaging materials, and adhesive tapes.

〔Example〕

Next, embodiments of the present invention will be described based on Examples.

Crystalline polypropylene having the composition and properties shown in Table 1 was fed to an extruder, extruded through a T-die at 280°C, and wound around a cooling drum to form a 750μ sheet. Stretch the sheet 5 times in the longitudinal direction while heating it to 120°C with a group of T-rolls,
It was cooled and introduced into a tenter heated to 175'O for about 10 minutes.
Stretched twice in the transverse direction and further relaxed at 5% at 155°C.
A biaxially stretched polypropylene film having a thickness of 15 μm was prepared in an atmosphere of 1, and one side of the film was subjected to a corona discharge treatment. The results are listed in Table 1.

In Examples 1 and 2 of the present invention, the glossiness was greatly improved.

Excellent transparency with low haze. Furthermore, it is slippery.

The film also has excellent anti-blocking properties.

In Example 2, the film also had antistatic properties.

On the other hand, Comparative Example 1. is inferior in haze and glossiness. Comparative Example 2, which is inferior in surface properties and blocking; Comparative Example 6, in which the addition amount is large, so it adheres to the roll, and it adheres to the film surface, resulting in poor haze, glossiness, sliding coefficient, and blocking shear force. Comparative Example 4, where a large number of voids were formed, resulting in poor haze and gloss. High [η] low air comparative example 5
is the glossiness.

Inferior to haze + j% Cη]. Comparative Example 6 with low air content and no additives was inferior in all aspects.

When the film of the present invention was processed for print lamination (laminated onto printed matter), the resulting printed matter was clear and glossy.

Procedure amendment 轡1. Indication of the matter fl 1982 Patent Application No. 196801J'32, Name of the invention: Two-wheel stretched polypropylene film 3, Amendr's initiative 5, No number of inventions increased by the amendment 6, ``Details of the invention'' in the specification subject to the amendment Column 7, "Explanation", Contents of Correction (1) Mei IIIfq Page 6, Line 13, L1 "Measure percentage" is corrected to "at++ constant" (1%).

(2) Same page 11 Table 1 Comparison 6th row, 1.1" column of paperset 1~" [9,75J is corrected to +97.5J.

Claims (1)

[Claims] (1) Intrinsic viscosity [η] 1.0-2. o, 1 oz part of crystalline polypropylene with an isotactic degree of 98% or more, nucleating agent o, o i ~i, ozzzff+s
, A biaxially oriented polypropylene film containing 0.05 to 20 parts by weight of a quinine compound and having a glossiness of 145 or more.