JPH02258852A - Polypropylene film - Google Patents

Abstract

PURPOSE:To obtain the title film excellent in both initial slipperiness and that with a lapse of days without impairing transparency, thus suitable for various packaging use by incorporating a crystalline propylene polymer with specified amount of butyl stearate and/or octyl stearate. CONSTITUTION:A composition is prepared by incorporating (A) 100 pts.wt. of a crystalline propylene polymer pref. 3-40g/10min in melt flow rate with (B) 0.01-1 pt.wt. of butyl stearate and/or octyl stearate of the formula (R is butyl or octyl) and (C) 0.01-1 pt.wt. of an antistatic agent (12-22C fatty acid glycerine ester or fatty acid diethanolamine) and/or slipping agent (18-22C higher fatty acid amide). This composition is then made into the objective film.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to polypropylene films.

More specifically, the present invention relates to a polypropylene film suitable for various packaging applications and having excellent initial and D-day slip properties.

[Conventional technology]

BACKGROUND ART Various polypropylene resin films have been produced and widely used for various packaging applications.

In general, when packaging materials are manufactured using polypropylene films, there have been drawbacks such as a decrease in productivity in the packaging process and poor opening of the resulting packaging materials due to lack of slip properties of the film.

In order to improve this drawback, there are a method of roughening the surface of the film to improve the slip property, and a method of forming a film by blending a large amount of slip agent and/or antistatic agent into polypropylene resin. Although the method of roughening the film surface is an inexpensive method, it has the disadvantage that transparency is significantly impaired when rounding imparts appropriate slip properties. In addition, the method of forming a film by blending a large amount of slip agent and/or antistatic agent with polypropylene resin is widely used, but the slip agent and antistatic agent that bleed out on the surface of the obtained film are easily damaged. It has the disadvantage that transparency deteriorates significantly.

We conducted intensive research on how to solve the illumination point. As a result, a film obtained from a composition obtained by blending a crystalline propylene polymer with butyl stearate and/or octyl stearate and predetermined amounts of an antistatic agent and/or a slip agent can be obtained without impairing transparency. It was discovered that the material has excellent slip properties both initially and over time, and based on this knowledge, the present invention was completed. As is clear from the above description, one object of the present invention is to provide a polypropylene film that has excellent slip properties both initially and over time.

[Means to solve the problem]

The present invention has the following configuration.

(IJ 100 parts by weight of crystalline propylene polymer, 0.01 to 1.0 parts by weight of butyl stearate and/or octyl stearate, and 0.01 to 1.0 parts by weight of antistatic agent and/or slip agent) A polypropylene film characterized by using a composition comprising:

(2) As an antistatic agent, use glycerin fatty acid ester or fatty acid jetanolamine with a fatty acid number of 12 to 22 carbon atoms as 18i or more, and as a slip agent, use a glycerin fatty acid ester with a carbon number of 12 to 22 or more as a slip agent.
The polypropylene film according to item 1 above, which uses ~22 higher fatty acid amides.

The crystalline propylene polymer used in the present invention includes a crystalline propylene homopolymer, a crystalline ethylene-propylene random copolymer, propylene and phtene-1, pentene-1, hexene-1, heptene-1, octene-1,
Crystalline random copolymers of one or more α-olefins such as decene-1, propylene and ethylene with butene-1, pentene-1, hexene-1, heptene-1, octene-1, decene-1, etc. A propylene component such as a crystalline random copolymer with one or more α-olefins
0! Contains more than the amount of propylene, ethylene and/or
Or a crystalline random copolymer with an α-olefin having 4 or more carbon atoms, or 28! It is a mixture of the above. The melt flow rate (J
Based on IS K 7210, temperature 230°C, load 2.
The amount of molten resin discharged per 10 minutes when 4I is added to No. 16 is not particularly limited, but is preferably 3 to 401710.
It's worth it. The crystalline ethylene-propylene random copolymer preferably has an ethylene content of 0.1 to 10% by weight, particularly preferably 1 to 8% by weight. The crystalline propylene-butene-1 random copolymer preferably has a butene-1 content of 0.3 to 30% by weight, particularly preferably 1.5 to 20% by weight.

In addition, crystalline propylene-α-olefin (butene-1
except for. ) The random copolymer preferably has an α-olefin content of 0.3 to 20% by weight. The crystalline propylene polymer can be produced, for example, by homopolymerization of propylene, copolymerization of propylene and ethylene, propylene and butene-1, heptene-1, hexene-1, heptene-1, octene-1,
It can be obtained by copolymerization with one or more α-olefins such as decene-1, or by random copolymerization of propylene and ethylene with one or more of the above-mentioned α-olefins.

Butyl stearate and octyl stearate used in the present invention are generally represented by C,, H□COR (R nibutyl group or octyl group). The blending ratio of butyl stearate and octyl stearate is 0.01 to 1.0 parts by weight, respectively, based on 100 parts by weight of the crystalline propylene polymer. If the blending ratio is less than 1 part by weight of O, O', the effect of improving the slip property of the film when the obtained composition is made into a film will not be sufficiently exhibited;
．． If the amount exceeds 0 parts by weight, the butyl stearate or the octyl stearate may bleed out on the surface of the film when the resulting composition is used, and the anti-blocking properties of the film may be significantly deteriorated. ° It is undesirable because it generates smoke during film production and contaminates cooling rolls and the like.

The antistatic agent and/or slip agent used in the present invention is a polyhydric alcohol ester of a fatty acid or a fatty acid amine derivative. Esters with jetanolamine, stearyl alcohol, etc. Examples include glyceride laurate, glyceride stearate, behenin-derived jetanolamine, jetanolamine stearate, jetanolamine stearate stearyl ester, or mixtures of two or more of these. . In addition, as a slip agent, stearamide, erucamide, oleic acid amide, N-N ethylene bisstearamide, stearic acid jetanolamide, or a mixture of six or more of these, each having a fatty acid carbon number of 18 to 22, may be used. can be given. The blending ratio of the antistatic agent and /l or slip agent is 0.01 to 1.0 parts by weight per 100 parts by weight of the crystalline propylene polymer.

If the blending ratio is less than 0.01 part by weight, the effect of improving the slip property of the film when the obtained composition is made into a film will not be sufficiently exhibited, and if it exceeds 1.0 part by weight, the effect of improving the slip property of the film will not be sufficiently exhibited. When the resulting composition is used to form a film, the antistatic agent and slip agent bleed out onto the surface of the film, impairing the transparency of the film, which is undesirable.

The composition used for the polypropylene film of the present invention contains various additives that are usually added to propylene polymers, such as antioxidants (such as phosphorus antioxidants, sulfur antioxidants, and phenolic antioxidants). ), neutralizing agents (metal salts of higher fatty acids, hydrotalcite, etc.), anti-blocking agents (silica, zeolite, melamine formaldehyde condensate spherical powder, etc.) can be used within the range that does not impair the purpose of the present invention. .

The composition used for the polypropylene film of the present invention includes a crystalline propylene polymer, butyl stearate and/or octyl stearate, an antistatic agent and/or
& Bamboo slip agent Furthermore, predetermined amounts of the above-mentioned various additives are added using an ordinary stirring mixer such as a Hensel mixer (trade name),
It can be obtained by stirring and mixing using a super mixer or a ribbon blender, and it can also be obtained as pellets by melt-kneading and pelletizing the mixture in an ordinary single-screw extruder, twin-screw extruder, roll, etc. You can also do it. Further, the antistatic agent or slip agent is individually blended with the crystalline propylene polymer and pelletized, and the pellets of the crystalline propylene polymer are blended into pellets using a blender at a predetermined blending ratio. It can also be obtained by The polypropylene film of the present invention can be obtained by forming such a composition into a film using a conventional inflation method, T-die method, or the like. Especially in the T-die method, melt kneading temperature 18
The method of melting and cross-extruding at 0 to 260°C, rapidly cooling to 60°C or less to form a film, and then subjecting the surface to surface treatment such as corona discharge treatment as necessary to form a film does not impair transparency. This is desirable because it results in a film with excellent initial slip properties and slip properties over time.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the scope of the present invention is not limited thereby.

Note that the performance evaluation of the films carried out in Examples and Comparative Examples was carried out by the following method.

1) Slip property (sliding friction coefficient) 223℃, 50%RH
A film kept for 24 hours and a film kept for 168 hours were used as samples, and ASTMD 1894-64
Slip property was shown by the coefficient of dynamic friction measured using a method based on . The smaller this value is, the better the slip property is.

2) Transparency = Films kept at 23°C and 50% RH for 24 hours and 168 hours were used as samples, and the transparency was determined by the haze value (unit: 2%) measured in accordance with ASTM D 1003 K. Indicated. The smaller this value is, the better the transparency is.

3) Bleedability = 23°C, 50% R1' (24 hours and 168 hours kept at 23°C value 24
B, I(
Unit: %). The smaller the B and I values, the better the bleedability.

4) 77°C O'7 Kingability: 1 at 23℃, 501RH
A film kept for 68 hours was used as a sample, and the corona-treated sides of the film were superimposed on each other to form a mosquito superimposed film 4.
After applying a load of υ1 kg per cI/1 and keeping it at 40°C for 24 hours, the peel strength of the stacked films was measured at 23°C and 50% RH to determine the degree of anti-blocking (unit:
#i/4cd). The smaller this value is, the better the anti-blocking property is.

5) Smoke-emitting property: The smoke generated near the die during molding was visually confirmed, and the smoke-emitting property was rated as 1 for no smoke, 2 for some smoke, and 3 for a lot of smoke.

Examples 1 to 14, Comparative Examples 1 to 5 As a crystalline propylene polymer, the melt flow rate was 8.
0#/10 minutes, ethylene content 3.0 weight kettle, butene content 3.0 weight kettle, crystal melting point measured by DSC method is 14
Powdered crystalline ethylene-propylene-butene at 0°C
Butyl stearate or octyl stearate, a slip agent (erucic acid amide), and an antistatic agent (stearic acid moglyceride) are added to 100 parts by weight of the ternary random copolymer in the amounts listed in Table 1 below, and an antioxidant. (BHT) 0.1 part by weight, 0.05 part by weight of neutralizing agent (calcium stearate) and 0.2 part by weight of anti-blocking agent (silica) were placed in a Hensel mixer (trade name) and stirred for 2 minutes. After mixing, the mixture was heated to a melt mixing temperature of 200°C using a single screw extruder with a diameter of 40 m.
The mixture was melt-extruded and pelletized. The obtained pellets were molded into a film with a thickness of 25 μm using a molding machine equipped with a T-die under the processing conditions listed in Table 1, and one side of the film was subjected to corona discharge treatment to obtain a single-sided treated film. Using the obtained single-sided treated film, film performance was evaluated by the above evaluation method. The results are shown in Table 1.

As can be seen from Table 1, Examples 1 to 14 are all made by blending butyl stearate or octyl stearate and an antistatic agent and/or a slip agent with the crystalline propylene polymer according to the present invention. Compared to Comparative Example IK, which uses a composition in which only an antistatic agent and/or a slip agent is blended with a crystalline propylene polymer, initial and oral slip properties are improved, and at the same time, the film surface is improved. However, the anti-blocking properties of the resulting film were significantly reduced, and the smoke-emitting properties were also deteriorated.

Comparative Examples 3 and 4 are cases where crystalline propylene is added, and although the initial and aging slip properties of the film are improved, the bleed properties (B, I values) of the film are extremely poor, and the transparency of the film is reduced. However, it can be seen that the smoke generation property is also worsened.

Comparative Example 5 is a case where only butyl stearate was added to the crystalline propylene polymer without adding an antistatic agent or a slip agent, but the initial and aging slip properties and anti-blocking properties of the obtained film were remarkable. It turns out to be inferior.

Examples 15 to 17, Comparative Example 6 As a crystalline propylene polymer, melt flow rate 8
．． 0.19/10 minutes, ethylene content 3.0 weight kettle, butene content 3.0 weight kettle, powdered crystalline ethylene-propylene-butene 1 ternary random with a crystal melting point of 140°C measured by DSC method. Butyl stearate and a slip agent (oleic acid amide) were added to 100 parts by weight of the copolymer in the amounts listed in Table 2 below, and an antioxidant (BHT) was added to 100 parts by weight of the copolymer.
)0.1 part by weight, neutralizing agent (calcium stearate))
0.1 part by weight and anti-blocking agent (silica) 0
．． After 311 parts were put into a Hensel mixer (trade name) and stirred and mixed for 2 minutes, the mixture was melt-cross-extruded using a single-screw extruder with a diameter of 40 tx at a melt-mixing temperature of 200°C to pelletize. The obtained pellets were molded into a 25 μm thick film using a water-cooled inflation molding machine under the processing conditions listed in Table 2. Using the obtained film, the performance of the Sifilm was evaluated by the above evaluation method. The results are shown in Table 2.

As can be seen from Table 2, all of Examples 15 to 17 are films using compositions in which butyl stearate and a slip agent are blended with the crystalline propylene polymer according to the present invention. It can be seen that the initial and oral slip properties are improved compared to the film of Comparative Example 1, which uses a composition comprising only a slip agent blended with a polymer, and the film also has excellent bleed properties.

Examples 18-20. Comparative Example 7 Melt flow rate as crystalline propylene polymer 8.
0.9/10 minutes, ethylene content 3.0% by weight, DSC
A mixture of butyl stearate and a slip agent (erucic acid amide) was added to 100 parts by weight of a powdered crystalline ethylene-propylene random copolymer having a crystal melting point of 150°C as measured by the method described in Table 2 below. Add 0.1 part by weight of antioxidant (BIT), 0.1 part by weight of neutralizing agent (calcium stearate) and 0.3 parts by weight of anti-blocking agent (silica) to Hensel mixer (trade name) K2. After stirring and mixing for a minute, the mixture was
Using a 0U single-screw extruder, the mixture was melt-cross-extruded at a melt-cross-wire temperature of 200° C. and pelletized. The obtained pellets were molded into a 25 μm thick film using a water-cooled inflation molding machine under the processing conditions listed in Table 2. Using the nine films obtained, the performance of the film was evaluated according to the evaluation method described above.

The results are shown in Table 2.

As can be seen from Table 2, the films of the present invention obtained in Examples 18 to 20 were compared to the film of Comparative Example 7, which used a composition containing only a slip agent in a crystalline propylene polymer. It can be seen that the initial and aging slip properties are improved, and the film also has excellent bleed properties.

Examples 21 to 23, Comparative Example 8 Melt flow rate as crystalline propylene polymer)8.
Butyl stearate and a slip agent (erucic acid amide) were added to 100 parts by weight of a powdered crystalline propylene homopolymer having a crystal melting point of 160°C as measured by the DSC method, as described below. Amounts listed in Table 2 and antioxidant (B I T ) 0.1
Parts by weight, 0.1 parts by weight of a neutralizing agent (calcium stearate), and 0.3 parts by weight of an anti-blocking agent (silica) were placed in a Hensel mixer (trade name), stirred and mixed for 2 minutes, and then the mixture was Using a 40 m single-screw extruder, the mixture was melt-cross-extruded at a melt-cross-wire temperature of 200°C and pelletized. The obtained pellets were molded to a thickness of 25 μm using a water-cooled inflation molding machine under the processing conditions listed in Table 2.
A film was formed. Using the obtained film, the performance of the film was evaluated according to the above evaluation method. The results are shown in Table 2.

As can be seen from Table 2, the films of the present invention obtained in Examples 20 to 23 had an initial It can be seen that the oral slip properties are improved and the film bleed properties are also excellent.

〔Effect of the invention〕

The polypropylene film of the present invention has excellent initial and aging slip properties, and also has a small amount of bleeding onto the film surface.Since the initial slip properties are improved, wrinkles do not occur during film formation. It is a film that has excellent prevention and rewind properties from mill rolls, and has excellent workability during packaging processing. Furthermore, as the bleed property has been improved, there is less build-up on contact rolls during printing processing and less bleed on the film surface after packaging, making it possible to clearly see the contents and create clean packaging. It is suitable as a packaging film.

that's all

Claims (2)

[Claims] (1) Add 0.0% butyl stearate and/or octyl stearate to 100 parts by weight of crystalline propylene polymer.
1. A polypropylene film characterized by using a composition comprising 0.01 to 1.0 parts by weight of 0.01 to 1.0 parts by weight and 0.01 to 1.0 parts by weight of an antistatic agent and/or a slip agent. (2) One or more glycerin fatty acid esters or fatty acid diethanolamines whose fatty acids have 12 to 22 carbon atoms are used as antistatic agents, and one or more fatty acid diethanolamines whose fatty acids have 18 to 22 carbon atoms are used as slip agents.
The polypropylene film according to claim 1, wherein 22 higher fatty acid amides are used.