JPH04212848A - Composite biaxially oriented polypropylene resin film - Google Patents

Abstract

PURPOSE:To improve sliding properties and desorbing properties by blending a 0.2-3.0 pts.wt. silicone gum and 0.05-2.0 pts.wt. silicone resin powder to the 100 pts.wt. resin component of a laminated resin layer only in the first laminated resin layer. CONSTITUTION:The title film is composed of the three layer structure of a biaxially oriented polypropylene resin film layer, a first laminated resin layer consisting of the mixed resin of the random copolymer of ethylene-propylene- buten laminated on one surface of the resin film layer and a buten.1 polymer and a second laminated resin layer made up of the mixed resin of one kind or more of buten copolymers laminated on the other surface or the buten copolymer and a polybuten and/or an ethylene-propylene copolymer. A silicone gum composed of a polysiloxane polymerizing section having viscosity at 25 deg.C of 10<7> centistokes or more and silicone resin powder are mixed with the 100 pts.wt. resin component only in the first laminated resin layer at that time.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a composite biaxially oriented polypropylene resin film having physical properties suitable as a packaging material for obtaining various packaging bodies, and is suitable for high-speed packaging using an overlap type automatic packaging machine. To provide a film that has high-temperature slip properties, heat-sealing properties, and transparency that can be used as a packaging material, and can provide a package with a good finish.

0002

[Prior Art] Biaxially oriented polypropylene resin films have excellent properties such as transparency, water vapor barrier properties, mechanical strength, and chemical resistance, and are particularly suitable for types that allow the contents inside the package to be seen through. Although it is widely used as a packaging material, it has the drawback of insufficient heat sealing performance.

[0003] For this reason, biaxially oriented polypropylene resin films used in fields where heat-sealing performance is required include, for example, polyethylene, ethylene-propylene copolymers, A composite film is used in which a heat sealant layer made of an ethylene-butene 1 copolymer or a mixed resin thereof is laminated by a coextrusion method, a lamination method, or the like. In particular, a composite biaxially stretched polypropylene resin film comprising a heat sealant layer made of the aforementioned polyethylene, ethylene-propylene copolymer, ethylene-butene monocopolymer, or a mixed resin of these, etc. It is a conventional overlapping type packaging material because of its advantages such as the ability to shorten the manufacturing process for polypropylene resin films and the ability to reuse manufacturing waste as raw material resin for biaxially oriented polypropylene resin films. Biaxially oriented polypropylene resin films having a polyvinylidene chloride coating layer have begun to be used in the field of packaging materials, and can be used in automatic packaging machines. Development of a composite biaxially oriented polypropylene resin film that has a heat sealant layer that has both heat sealing performance that allows heat sealing at a temperature that does not melt the film layer and a short pressure bonding time, and good slip properties. It is progressing.

For example, JP-A No. 62-233248 discloses a composite biaxial structure having a heat sealant layer made of a propylene-ethylene random copolymer or a propylene-ethylene-butene 1 random copolymer containing silicone resin powder. Stretched polypropylene resin film
Furthermore, JP-A-2-60745 discloses a propylene-ethylene random copolymer containing polydiorganosiloxane gum or a propylene-ethylene-butene-1
A composite biaxially oriented polypropylene resin film having a heat sealant layer made of a random copolymer is described as a composite biaxially oriented polypropylene resin film that has both heat sealing properties and slipperiness that can be used in automatic packaging machines. .

[0005]

[Problems to be Solved by the Invention] However, the composite biaxially oriented polypropylene resin films described in the above-mentioned JP-A-62-233248 and JP-A-2-60745 are not compatible with the composite biaxially oriented polypropylene resin films that have been developed in recent years. The heat sealability is not sufficient for use in wrap-type high-speed automatic packaging machines, and the slipperiness is particularly poor at high temperatures. Also, the removability is poor, and wrinkles occur in the heat-sealed portion of the resulting package, making it impossible to obtain a package with a tight feel and good finish.

In contrast, the present invention provides that the heat sealant layer that comes into contact with the metal guide plate and hot plate of an automatic packaging machine has extremely good slipperiness at high temperatures and does not come into contact with the contents inside the package. The heat sealant layer, which is the side to be covered with, has an appropriately adjusted slipperiness with respect to the contents, so that there is no misalignment of the folded part of the package due to the high slipperiness, and To provide a composite biaxially stretched polypropylene resin film that can be heat-sealed using an overlap type high-speed automatic packaging machine and provides a package with a good finish.

[0007]

[Means for Solving the Problems] The composite biaxially stretched polypropylene resin film of the present invention comprises a base material layer made of a polypropylene resin film to which biaxial stretching has been introduced, and a base material layer laminated on one side of the base material layer. It has a three-layer structure: a first laminated resin layer that is placed on the base layer, and a second laminated resin layer that is laminated on the surface of the base material layer on the opposite side of the first laminated resin layer.

In the composite biaxially stretched polypropylene resin film of the first invention, the resin components of the first laminated resin layer have an ethylene component content of 0.5 to 8.0% by weight and a butene component content of 0. .5 to 5.0% by weight of a random copolymer of ethylene-propylene-butene (30 to 70% by weight) and a butene monopolymer (70 to 30% by weight). The resin component of the resin layer is one or more butene-based copolymers selected from ethylene-butene copolymer, ethylene-propylene-butene copolymer, and propylene-butene copolymer, or the butene-based copolymer. It is made of a mixed resin of a copolymer and a polybutene and/or an ethylene-propylene copolymer, and the content of the butene component in the resin component of the second laminated resin layer is 5 to 70.
within the range of % by weight, and only in the first laminated resin layer, based on 100 parts by weight of the resin component of the laminated resin layer,
Silicone gum made of a polysiloxane polymer having a viscosity of 107 centistokes or more at 25°C 0.2~
3.0 parts by weight and 0.05 to 2.0 parts of silicone resin powder
Parts by weight are blended.

[0009] The composite biaxially oriented polypropylene resin film of the second invention has the structure of the composite biaxially oriented polypropylene resin film of the first invention, in which the butene monopolymer in the first laminated resin layer is However, JIS K6
30-90% by weight of butene-1 polymer with MFR (melt flow rate) defined by 760 of 1-8 g/10 minutes
and MFR (also defined in JIS K6760)
It consists of a mixture of butene and monopolymer 70 to 10% by weight with a melt flow rate of 18 to 50 g/10 min.

[0010] The composite biaxially oriented polypropylene resin film of the third invention has the structure of the composite biaxially oriented polypropylene resin film of the first invention or the second invention, in which the resin in the second laminated resin layer is The component consists of a propylene-butene copolymer having a butene component content of 5 to 50% by weight.

[0011] In the composite biaxially stretched polypropylene resin film of each of the present inventions having the above structure, the first laminated resin layer surface of the film becomes the outer surface layer of the package, that is, the second laminated resin layer surface serves as the content layer. It is used as a packaging material by making it the surface that comes into contact with objects.

[0012] In such a composite biaxially stretched polypropylene resin film, the base material layer made of a polypropylene resin film to which biaxial stretching has been introduced is made of an ordinary biaxially stretched polypropylene resin film, such as polypropylene homopolymer. Polymer, a copolymer of polypropylene and a small amount of α-olefin such as ethylene, or a film made of a mixed resin of these, etc.
As in the case of axially oriented polypropylene resin film,
A film made of a mixed resin with other resins may also be used within a range that does not impair the various properties of the biaxially oriented polypropylene resin film. In particular, for 100 parts by weight of polypropylene resin, for example, 5 parts of low molecular weight thermoplastic resin, such as petroleum resin or terpene resin, which is hard and brittle at room temperature.
When using a biaxially oriented polypropylene resin film made of a mixed resin containing about 30 parts by weight as a base material layer, a composite material having extremely good properties for folding when applied to an automatic packaging machine is used. It becomes a biaxially stretched film.

Furthermore, the base material layer made of the biaxially oriented polypropylene resin film mentioned above has, for example,
It goes without saying that additives such as antioxidants, lubricants, antistatic agents, and ultraviolet absorbers may be added as appropriate.

[0014] The first laminated resin layer laminated on one side of the base layer made of a polypropylene resin film subjected to biaxial stretching has an ethylene component content of 0.5 to 8.0.
Random copolymer of ethylene-propylene-butene with a butene component content of 0.5-5.0% by weight 30-7
0% by weight and 70-30% by weight of butene-1 type polymer as a resin component, and the viscosity at 25°C is 107 cm for 100 parts by weight of the mixed resin that makes up this resin component. It contains 0.2 to 3.0 parts by weight of silicone gum made of a polysiloxane polymer of Stokes or higher and 0.05 to 2.0 parts by weight of silicone resin powder.

[0015] Ethylene component content: 0.5 to 8.0% by weight
, ethylene with a butene component content of 0.5 to 5.0% by weight
In the first laminated resin layer formed using a mixed resin of a random copolymer of propylene-butene and a butene-1 type polymer as a resin component, the butene-1 type polymer is a resin component in the first laminated resin layer. When it becomes less than 30% by weight,
Sufficient low-temperature heat sealability by the first laminated resin layer cannot be obtained, and if it exceeds 70% by weight, film forming suitability deteriorates, and workability in the process of forming the first laminated resin layer deteriorates. Furthermore, the workability of the composite biaxially stretched polypropylene resin film in an automatic packaging machine also deteriorates.

[0016] It should be noted that butene in the first laminated resin layer
The MFR (melt flow rate) defined in JIS K 6770 is 1 to 8 g/1 for type 1 polymers because a wide range of heat sealing temperatures can be set and packaging with a good finish can be obtained. 10 minutes, preferably 2-4
g/10 min of butene-1 polymer 30 to 90% by weight, preferably 50 to 70% by weight, also JIS K 677
MFR (melt flow rate) defined as 0 is 18
~50g/10min, preferably 20~25g/10min butene monopolymer 70~10% by weight, preferably 50~
Preference is given to using a mixture of 30% by weight.

That is, when the butene-1 type polymer in the first laminated resin layer has an MFR (melt flow rate) of 1 to 8 g/10 min exceeding 90% by weight, the usable heat The sealing temperature range becomes narrower, and wrinkles are more likely to occur in the resulting packaging, which can be a problem especially when used for high-speed packaging using automatic packaging machines. This is improved by mixing a butene monopolymer with a flow rate of 18 to 50 g/10 min. However, MFR (melt flow rate) is 18-50g
When the butene/1-based polymer exceeds 70% by weight of the butene/1-based polymer, the flow of the resin becomes too good and the film forming performance of the first laminated resin layer deteriorates. Another problem may occur.

The silicone gum added to the first laminated resin layer is made of a two-dimensional polymer having a polysiloxane skeleton, and is in the form of a gum with a viscosity of 107 centistokes or more at 25°C and a molecular weight of 106 or more. A substance that exhibits
For example, polydimethylsiloxane or one of the methyl groups in the side chain.
These include polydimethylsiloxane modified products in which some portions are substituted with other functional groups.

The silicone gum used in the first laminated resin layer in the composite biaxially stretched polypropylene resin film of the present invention is different from silicone oil, silicone rubber, and even silicone resin. The viscosity at °C is 5 to 10 centistokes, the silicone rubber is a two-dimensional polymer having siloxane bonds via alkyl groups, and the silicone resin is a three-dimensionally bonded polysiloxane. clearly differentiated.

[0020] When the amount of silicone gum blended in the first laminated resin layer is less than 0.2 parts by weight based on 100 parts by weight of the resin component of the first laminated resin layer, the effect of adding silicone gum is Moreover, if the amount exceeds 3.0 parts by weight, not only will the effect of increasing the amount of silicone gum not be obtained, but the transparency of the composite biaxially oriented polypropylene resin film itself will decrease, and roll contamination may occur. or even worse, when it is in the winding state, the second
Since the silicone gum may transfer to the surface of the laminated resin layer, 0.2 parts by weight to 3.0 parts by weight, preferably 0.2 parts by weight to 100 parts by weight of the resin component in the first laminated resin layer.
．． It is blended in an amount of 3 to 1.0 parts by weight.

The silicone resin powder, which is the other additive component in the first laminated resin layer, is basically a three-dimensionally bonded silicone resin having siloxane bonds,
Various modified silicone resin powders can be used as long as they do not impair the effect of the first laminated resin layer.

The silicone resin powder is preferably spherical with an average particle size of about 1 to 7 μm.

[0023] The blending amount of silicone resin powder is 0.0 parts by weight per 100 parts by weight of the resin component in the first laminated resin layer.
If the amount is less than 5 parts by weight, there will be no effect of adding silicone resin powder, and if it exceeds 2.0 parts by weight, not only will the effect of increasing the amount of silicone resin powder not be obtained, but the composite biaxial This may reduce the transparency of the stretched polypropylene resin film itself, cause roll contamination, or even cause the silicone resin powder to transfer to the surface of the second laminated resin layer when the film is wound. Since the physical properties may be deteriorated, the amount is 0.05 to 2.0 parts by weight per 100 parts by weight of the resin component in the first laminated resin layer.
It is blended in a proportion of 0 parts by weight, preferably 0.1 to 1.0 parts by weight.

[0024] The second laminated resin layer laminated on the other side of the base material layer made of a polypropylene resin film subjected to biaxial stretching is such that the resin component in the laminated resin layer is ethylene-butene. one or more butene-based copolymers selected from ethylene-propylene-butene copolymers and propylene-butene copolymers, or the butene-based copolymers and polybutene and/or ethylene-propylene. It is made of a mixed resin with a copolymer, and the content of the butene component in the resin component is within the range of 5 to 70% by weight.

[0025] If the content of the butene component in the resin components in the second laminated resin layer is a small amount, less than 5% by weight, the heat sealing performance at low temperatures will deteriorate, and the butene content will decrease.
Good heat sealability cannot be obtained with the first laminated resin layer containing 70 to 30% by weight of the monopolymer, and if it exceeds 70% by weight, the second laminated resin layer will not be formed. In this case, the film forming suitability at the time of forming the film deteriorates, and the workability in the process of forming the second laminated resin layer deteriorates.

The first laminated resin layer and the second laminated resin layer described above contain additives commonly used in heat sealant layers,
For example, it goes without saying that antioxidants, anti-blocking agents, lubricants, etc. can be added as appropriate.

Composite 2 of the present invention having the above structure
The axially oriented polypropylene resin film is produced by: (1) obtaining a raw sheet with a three-layer configuration of a polypropylene resin layer, a first laminated resin layer, and a second laminated resin layer by co-extrusion molding, and then forming the raw sheet (2) After extruding and laminating a first laminated resin layer and a second laminated resin layer on a raw sheet obtained by extrusion molding a polypropylene resin, (3) After extruding and laminating a first laminated resin layer and a second laminated resin layer on a polypropylene resin film that has been uniaxially stretched in the longitudinal direction, It can be obtained by a method of stretching in the transverse direction, etc.

[0028] In the stretching in the longitudinal direction in the manufacturing process of the composite biaxially stretched polypropylene resin film according to (1) and (2) above, that is, the first laminated resin layer and the second laminated resin layer are laminated. In the step of stretching the unstretched sheet in the longitudinal direction, compared with the stretching step in the longitudinal direction in the manufacturing process of the composite biaxially oriented polypropylene resin film according to (3), the process of stretching the unstretched sheet in the longitudinal direction Because of the presence of the low melting point resin layer, it is necessary to perform the stretching at a lower temperature.

Furthermore, if the melting points of the resin components in the first laminated resin layer and the second laminated resin layer are very low, the low melting point resin layer may melt during roll stretching in the longitudinal direction. Since it may stick to the rolls or become sticky, the first laminated resin layer is stretched in the longitudinal direction so that the side that comes into contact with the rolls, where roll removal and stickiness are most likely to occur, is the first laminated resin layer. Alternatively, the first laminated resin layer and the second laminated resin layer are extruded and laminated onto the uniaxially stretched polypropylene resin film after the longitudinal stretching step, and this is laminated using a tenter. It is preferable to use method (3), which involves stretching in the transverse direction.

[0030] In the manufacturing process of the above-mentioned composite biaxially stretched polypropylene resin film, the stretching in the longitudinal direction is usually carried out by a roll stretching method at a stretching temperature of about 110 to 160°C to a stretching ratio of about 4 to 7 times. Further, the transverse stretching is carried out by a tenter method at a stretching temperature of about 130 to 170°C at a stretching ratio of about 7 to 12 times.

In the manufacturing process of the composite biaxially stretched polypropylene resin film described above, following the transverse stretching step, the film is stretched in the transverse direction for 5 to 15 minutes while heating at 100 to 170°C as necessary. Relaxation heat treatment is performed to shrink the material by approximately %.

[0032] The composite biaxially oriented polypropylene resin film obtained by the above process has good sliding properties, and even when it is used in an automatic packaging machine as it is, it does not exhibit any slippage during the feeding process or the contact process with rolls. Although the trouble of charging due to friction can be avoided, if a higher degree of antistatic property is required or if it will be subjected to a printing process or metal vapor deposition process, a second surface treatment such as corona discharge may be necessary. This can be done on the surface of the laminated resin layer.

However, since surface treatment by corona discharge etc. leads to a decrease in heat sealing performance, it is necessary to keep it to the minimum necessary level. In particular, corona discharge treatment to the surface of the first laminated resin layer is necessary. If this is done, the action of the silicone gum will be inhibited due to a decrease in the heat sealing performance of the laminated resin layer and bleeding of the internally added antistatic agent. You will not be able to obtain

[0034]

EXAMPLES The specific structure of the composite biaxially stretched polypropylene resin film of the present invention will be explained below based on manufacturing examples.

Example 1 Isotactic polypropylene resin (MFR: 2.
Mixed resin 1 of 90 parts by weight of 0g/10 minutes) and 10 parts by weight of petroleum resin [Arakawa Chemical Co., Ltd., Alcon P-100]
A mixed composition of T. - An unstretched sheet (aA) of polypropylene resin having a thickness of 950 μm was obtained by melt extrusion molding with a die and cooling with a cast roll at 40° C.

Next, a polypropylene resin sheet (aA
) Content of ethylene component: 4.0% by weight
, 60 parts by weight of an ethylene-propylene-butene random copolymer with a butene component content of 2.0% by weight, and MFR
To 100 parts by weight of a mixed resin with 40 parts by weight of butene 1 polymer having a weight of 4.0 g/10 minutes, 0.5 parts by weight of silicone gum having a viscosity of 5 x 107 centistokes at 25°C and an average particle size of 3 μm. A mixed composition containing 0.5 parts by weight of silicone resin powder and 0.2 parts by weight of erucic acid amide was added to the other side of the polypropylene resin sheet (aA). 60 parts by weight of an ethylene-propylene-butene random copolymer with a content of 4.0% by weight and a butene component content of 2.0% by weight, and MFR
A mixture in which 0.2 parts by weight of erucic acid amide and 0.2 parts by weight of silicon dioxide powder are mixed with 100 parts by weight of a mixed resin with 40 parts by weight of butene 1 polymer with a content of 4.0 g/10 minutes. The compositions were extruded and laminated to a thickness of 45 μm using two extruders, respectively, to obtain a 3-layer laminated sheet (aB).

Furthermore, the 3-layer laminated sheet (aB) is subjected to roll stretching of 5 times in the longitudinal direction at a stretching temperature of 125°C, and in the subsequent continuous process, tenter stretching of 9 times in the transverse direction at 160°C. and then heated at 160°C in the transverse direction for 7
By giving a relaxation of The first layer with a thickness of 1μ containing
and a second laminated resin layer with a thickness of 1μ laminated on the base material layer surface on the opposite side of the first laminated resin layer.
A composite biaxially oriented polypropylene resin film "a-1", which is an example product of the present invention based on the layer structure, was obtained.

Example 2 An example product of the present invention was prepared by subjecting the second laminated resin layer surface of the composite biaxially stretched polypropylene resin film “a-1” obtained in Example 1 to corona discharge treatment. A composite biaxially stretched polypropylene resin film that is
a-2" was obtained.

Example 3 In the manufacturing process of the composite biaxially stretched polypropylene resin film “a-1” of Example 1, the MFR was 4.0 g/
Instead of 10 minutes of butene-1 polymer, the MFR is 18
．． A composite biaxially oriented polypropylene resin film, which is an example product of the present invention, was prepared by using 0 g/10 min of butene-1 polymer and using the same procedure as in Example 1 for all other configurations. "a-3" was obtained.

Example 4 In the manufacturing process of the composite biaxially stretched polypropylene resin film “a-1” of Example 1, the MFR was 4.0 g/
Instead of 10 minutes of butene-1 polymer, the MFR is 4.
A mixture of 70% by weight of butene 1 polymer with an MFR of 25.0 g/10 min and 30% by weight of butene 1 polymer with an MFR of 25.0 g/10 min was used, and all other configurations corresponded to those in Example 1. In exactly the same manner as the procedure, composite biaxially stretched polypropylene resin film "a-4", which is an example product of the present invention, was prepared.
I got it.

Comparative Example 1 In the manufacturing process of the composite biaxially stretched polypropylene resin film “a-1” of Example 1, the first laminated resin layer was
A comparison of the present invention was carried out using a composition in which no silicone gum was added and 0.8 parts by weight of silicone resin powder was mixed, and all other configurations were carried out in exactly the same manner as in the corresponding procedure of Example 1. A composite biaxially stretched polypropylene resin film "A-1" consisting of an example product was obtained.

Comparative Example 2 In the manufacturing process of the composite biaxially stretched polypropylene resin film “a-1” of Example 1, the first laminated resin layer was
No silicone resin powder added, silicone gum 2.
The composition was prepared by mixing 0 parts by weight of silicon dioxide and 0.5 parts by weight of silicon dioxide, and all other compositions were as in Example 1.
Composite biaxially stretched polypropylene resin film "A
-2” was obtained.

Comparative Example 3 In the manufacturing process of the composite biaxially stretched polypropylene resin film “a-1” of Example 1, the first laminated resin layer was
No added silicone gum, viscosity at 25°C of 1
Composite 2 consisting of comparative example products of the present invention was prepared using a composition in which 0.5 parts by weight of silicone oil of 0.00 centistokes was mixed, and all other configurations were carried out in exactly the same manner as in the corresponding procedure of Example 1. An axially stretched polypropylene resin film "A-3" was obtained.

Example 5 Isotactic polypropylene resin (MFR: 2.
Mixed resin 1 of 90 parts by weight of 0g/10 minutes) and 10 parts by weight of petroleum resin [Arakawa Chemical Co., Ltd., Alcon P-100]
A mixed composition of T. - An unstretched sheet (bA) of polypropylene resin having a thickness of 750 μm was obtained by melt extrusion molding with a die and cooling with a cast roll at 40° C.

Next, a polypropylene resin sheet (bA
) was subjected to roll stretching 5 times in the longitudinal direction at a stretching temperature of 140° C. to obtain a uniaxially stretched polypropylene resin sheet (bB).

Furthermore, on one side of the uniaxially stretched polypropylene resin sheet (bB), the content of ethylene component is 4.0% by weight, and the content of butene component is 2.0% by weight.
Ethylene-propylene-butene random copolymer 60
0.5 parts by weight of silicone gum having a viscosity of 5 x 10 8 centistokes at 25° C. A mixed composition in which 0.4 parts by weight of silicone resin powder with an average particle size of 4.5μ and 0.2 parts by weight of erucic acid amide was mixed was also applied to the other side of the polypropylene resin sheet (bB). On the other hand, 100 parts by weight of a mixed resin of 40 parts by weight of an ethylene-propylene copolymer having an ethylene component content of 4.5% by weight and 60 parts by weight of an ethylene-butene copolymer having a butene component content of 20% by weight. , 0.2 parts by weight of erucic acid amide and 0.2 parts by weight of silicon dioxide
Parts by weight of the mixed composition were extruded and laminated to a thickness of 20 μm using two extruders, respectively, to obtain a 3-layer laminated sheet (bC).

[0047] Further, a laminate sheet with a three-layer structure (b
C) was subjected to 9x tenter stretching in the transverse direction at 160°C, followed by 7% relaxation in the transverse direction under heating at 160°C, whereby a biaxial stretch to a thickness of 20μ was introduced. a base material layer made of a polypropylene resin film, a first laminated resin layer having a thickness of 1.5 μ and laminated on one side of the base material layer and containing silicone gum and silicone resin powder; A composite biaxially oriented polypropylene resin, which is an example product of the present invention, has a three-layer structure with a second laminated resin layer having a thickness of 1.5μ laminated on the base material layer surface on the opposite side of the laminated resin layer. A film "b-1" was obtained.

Example 6 An example product of the present invention was prepared by subjecting the second laminated resin layer surface of the composite biaxially stretched polypropylene resin film “b-1” obtained in Example 5 to corona discharge treatment. A composite biaxially stretched polypropylene resin film that is
b-2" was obtained.

Example 7 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-1” of Example 5, an ethylene component with an ethylene component content of 4.5% by weight was used as the resin component of the second laminated resin layer. Instead of a mixed resin of 40 parts by weight of ethylene-propylene copolymer and 60 parts by weight of ethylene-butene copolymer with a butene component content of 20%, a propylene-butene copolymer with a butene component content of 25% by weight was used. A composite biaxially stretched polypropylene resin film "b-3", which is an example product of the present invention, was obtained by utilizing the coalescence process and performing all other configurations in exactly the same manner as the corresponding procedure of Example 5.

Example 8 An example product of the present invention was prepared by subjecting the second laminated resin layer surface of the composite biaxially stretched polypropylene resin film “b-3” obtained in Example 7 to corona discharge treatment. A composite biaxially stretched polypropylene resin film that is
b-4" was obtained.

Comparative Example 4 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-1” of Example 5, the first laminated resin layer was
A composite biaxially oriented polypropylene resin film "B-1" consisting of a comparative example product of the present invention was prepared using a composition without the addition of silicone gum, and all other configurations were carried out in exactly the same manner as the corresponding procedure of Example 5. ” was obtained.

Comparative Example 5 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-1” of Example 5, the first laminated resin layer was
No silicone resin powder added, no silicone gum.
A comparative example product of the present invention was prepared using a mixed composition in which 5 parts by weight of silicon dioxide and 0.5 parts by weight of silicon dioxide were mixed, and all other configurations were made in exactly the same manner as the corresponding procedure of Example 1. A composite biaxially stretched polypropylene resin film "B-2" was obtained.

Comparative Example 6 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-1” of Example 5, the first laminated resin layer was
25 parts by weight of a mixed resin of 40 parts by weight of an ethylene-propylene copolymer having an ethylene component content of 4.5% by weight and 60 parts by weight of an ethylene-butene copolymer having a butene component content of 20% by weight. 0.5 parts by weight of silicone gum having a viscosity of 5 x 108 centistokes at °C and an average particle size of 4
．． It was formed from a mixed composition in which 0.4 parts by weight of 5μ silicone resin powder and 0.2 parts by weight of erucic acid amide were mixed, and all other components were exactly the same as the corresponding procedure of Example 5. That is, all of the examples are the same except that both the resin component in the first laminated resin layer and the resin component in the second laminated resin layer are the same as the resin component in the second laminated resin layer in Example 5. Composite 2 consisting of comparative example products of the present invention was prepared in exactly the same manner as the corresponding procedure in 5.
An axially stretched polypropylene resin film "B-3" was obtained.

Comparative Example 7 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-3” of Example 7, the first laminated resin layer was
100 parts by weight of a propylene-butene copolymer with a butene content of 25% by weight, 0.5 parts by weight of silicone gum with a viscosity of 5 x 108 centistokes at 25°C, and a silicone resin with an average particle size of 4.5μ It was formed by a composition in which 0.4 parts by weight of powder and 0.2 parts by weight of erucic acid amide were mixed, and all other components were exactly the same as the corresponding procedure of Example 7, namely, All the steps were the same as in Example 7 except that the resin components in the first laminated resin layer and the resin components in the second laminated resin layer were the same as the resin components in the second laminated resin layer in Example 7. In exactly the same manner as above, a composite biaxially stretched polypropylene resin film "B-4" consisting of a comparative example product of the present invention was obtained.

Comparative Example 8 In the manufacturing process of the composite biaxially stretched polypropylene resin film “b-1” of Example 5, the first laminated resin layer was
60 parts by weight of an ethylene-propylene-butene random copolymer with an ethylene component content of 4.0% by weight and a butene component content of 2.0% by weight, and a butene-1 polymer with an MFR of 4.0 g/10 min. 40 parts by weight of a mixed resin, 0.5 parts by weight of silicone gum with a viscosity of 5 x 107 centistokes at 25°C, 0.4 parts by weight of silicone resin powder with an average particle size of 4.5μ, Acid amide 0.2
The second laminated resin layer is formed of a composition in which the content of the butene component is 20% by weight.
to 100 parts by weight of propylene-butene copolymer at 25°C.
A composition in which 0.5 parts by weight of silicone gum having a viscosity of 5 x 108 centistokes, 0.4 parts by weight of silicone resin powder having an average particle size of 4.5 μm, and 0.2 parts by weight of erucic acid amide are mixed. A composite biaxially stretched polypropylene resin film "B-5", which is a comparative example of the present invention, was obtained by using a composite biaxially stretched polypropylene resin film "B-5", which was a comparative example of the present invention.

[0056] Physical properties of each composite biaxially stretched polypropylene resin film according to Examples 1 to 8 and Comparative Examples 1 to 8, and the properties of packaging materials obtained by slitting each composite biaxially stretched polypropylene resin film into small widths. Automatic packaging machine suitability”
are summarized in Tables 1 to 12.

[0057] In the table, A side or A refers to the first laminated resin layer side of the composite biaxially oriented polypropylene resin film, and B side or B refers to the second laminated resin layer side of the composite biaxially oriented polypropylene resin film. means the laminated resin layer surface.

[0058] The numerical values obtained from the physical property tests were obtained by the following tests. 1) Haze (%) Value measured according to JIS K 6718 using a digital haze meter NDH-20D [Nippon Denshoku Industries Co., Ltd.]. 2) Change in transparency over time (△ haze (%)) 40
The haze (A%) obtained by subjecting the sample stored in an atmosphere at ℃ for 3 weeks to the measurement method in section 1) above, and the sample after measuring the haze (%) by the measurement method in section 1) above. A value expressed as the difference from the haze (B%) obtained by immediately washing with acetone and subjecting it to the measurement method described in item 1) above. Note that △ haze (%) indicates the extent to which the transparency of the film decreases over time due to bleed-out of additives, etc., and △ haze (%) is 0.
．． If it is 5 or less, it is difficult to visually discern the decrease in transparency over time, but if it is 1.0 or more, the decrease in transparency can be clearly determined with the naked eye. 3) Coefficient of friction (at room temperature) In an atmosphere of 20°C, the coefficient of friction between the first laminated resin layer surface and the second laminated resin layer in each sample made of composite biaxially stretched polypropylene resin film was calculated as follows: ASTMD
1894 (B method). 4) A heater capable of controlling the temperature of the coefficient of friction at high temperatures is attached to a horizontal plate attached to an aluminum plate coated with Teflon, similar to the heating plate in an automatic packaging machine, and the sample is placed on the warp side of the horizontal plate. At 120±2℃, the coefficient of friction between the sample and the Teflon-treated surface of the hot plate was determined as A.
Value measured in accordance with STM D 1894 (B method). 5) Antistatic property (static decay rate (%)) 6KV on sample
The amount of charge (X) when a charge of・Charge decay rate (%) measured using a “meter”
={(X-Y)×100}/The antistatic property was expressed as a numerical value represented by X. 6) Frictional electrification amount The amount of electrification (V) of the sample when the sample was rubbed against gauze for 1 minute was measured using a "Rotary Static Tester" manufactured by Koa Shokai Co., Ltd. 7) Heat-sealing strength Using a heat-sealing heat-sealer (Toyo Seiki Seisakusho), the thermally bonded part obtained by crimping under heat-pressing conditions of 2 kg/cm2 and 0.5 seconds was applied to Tensilon (manufactured by Orientec). ), the peel strength was measured when peeled at 200 mm/min. 8) Suitability for automatic packaging machines Each composite biaxially oriented polypropylene resin film was set in a U-3 type over wrapper manufactured by Tokyo Jidoki Co., Ltd., and soft cartons containing 20 cigarettes were individually wrapped. If packaging is possible at a rate of 250 pieces/min or more, the sealable temperature range of the top and bottom folds is displayed as the top and bottom sealable temperature range at the maximum speed, and the finished state of the resulting package can be visually inspected. I judged it. The maximum packaging speed of the packaging machine used was 280 pieces/min.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

[0063]

[Table 5]

[0064]

[Table 6]

[0065]

[Table 7]

[0066]

[Table 8]

[0067]

[Table 9]

[0068]

[Table 10]

[0069]

[Table 11]

[0070]

[Table 12] From the results of the above examples and comparative examples, ■ If either silicone gum or silicone resin powder is missing in the first laminated resin layer, slipperiness at high temperatures is poor and high speed Actual packaging becomes impossible (Experiment No. 6, Experiment No. 7, Experiment No. 13, Experiment No.
14).

The first laminated resin layer surface to which silicone gum or silicone resin powder is added is in contact with the contents in the package, and the second laminated resin layer surface to which silicone gum or silicone resin powder is not added is in contact with the contents of the package when the packaging machine When used in contact with a hot plate, the film has poor slipperiness and high-speed actual packaging is impossible (Experiment No. 2).

[0072] When the amount of silicone gum added increases, the slipperiness at high temperatures improves, but the heat sealability deteriorates on the surface of the first laminated resin layer, and the transparency of the film deteriorates due to bleed-out of the additive. Furthermore, the deposits accumulated on the rolls and hot plates of the packaging machine fall onto the film, deteriorating the finished appearance of the package. Furthermore, the finish of the package was slightly baggy and did not feel tight (Experiment No. 7).

[0073] When the first laminated resin layer contains silicone oil, although the slipperiness at high temperatures is slightly improved, the transparency of the film decreases due to additive bleed-out, and the packaging material High-speed packaging is impossible because wrinkles occur in the top and bottom seals (Experiment No. 8).

[0074] ■ When the first laminated resin layer contains appropriate amounts of silicone gum and silicone resin powder, the slipperiness at high temperatures is good, and moreover, high-speed packaging of 280 pieces/min is possible. (Experiment No. 1, Experiment No. 3, Experiment No. 4, Experiment No. 5). When using a mixture of butene-mono-polymers with different MFRs as the butene-mono-polymer in the first laminated resin layer, the probability that corners will occur at the rear of the folded part when obtaining a package can be greatly reduced. Moreover, the heat sealable temperature range is expanded (Experiment No. 5).

[0075] Corona discharge treatment can improve the antistatic performance, but the heat-sealable temperature range becomes narrower (Experiment No. 3).

■ The resin component of the second laminated resin layer is an ethylene-butene copolymer or the copolymer and ethylene-butene copolymer.
Mixed resin with propylene copolymer or propylene-
By using a butene copolymer, it is possible to obtain a package with a particularly good finish after packaging, and the heat-sealable temperature range is also expanded (Experiment No. 9, Experiment No.
．． 10, Experiment No. 11, Experiment No. 12).

In particular, by using a propylene-butene copolymer as the resin component of the second laminated resin layer, the heat sealing area on the low temperature side is further expanded, and even when subjected to corona discharge treatment, the packaging Because heat sealing can be performed without using high heat sealing temperatures that would cause wrinkles on the body,
A package with an extremely good finish can be obtained (Experiment No.
．． 11, Experiment No. 12).

[0078] Adding silicone gum to both the first laminated resin layer and the second laminated resin layer provides extremely good slipperiness at high temperatures; The slipperiness of the product also becomes too good, which causes the folded portion to shift during packaging, resulting in a finished product that lacks a tight feel after packaging (Experiment No. 17).

■ When the resin component of the first laminated resin layer consists of a mixed resin of ethylene-propylene copolymer and ethylene-butene copolymer or a propylene-butene copolymer, silicone gum and silicone resin Even if powder is blended, the sliding properties between the package and the hot plate of the packaging machine are insufficient, resulting in corners forming at the rear of the top and bottom seals of the package, making it impossible to obtain a package with a good finish ( Experiment No. 15
, Experiment No. 16).

[0080]

Effects of the Invention The composite biaxially stretched polypropylene resin film of the present invention comprises a base material layer made of a polypropylene resin film subjected to biaxial stretching, and a first layer laminated on one side of the base material layer. In a composite biaxially stretched polypropylene resin film having a three-layer configuration of a laminated resin layer and a second laminated resin layer laminated on the base layer surface opposite to the first laminated resin layer, the first laminated resin layer The resin component of the resin layer is
Ethylene-propylene-butene random copolymer 30
~70% by weight and 70-30% by weight of butene monopolymer
The resin component of the second laminated resin layer is one selected from ethylene-butene copolymer, ethylene-propylene-butene copolymer, and propylene-butene copolymer. The above-mentioned butene-based copolymer, or a mixed resin of the butene-based copolymer and polybutene and/or ethylene-propylene copolymer, is used only in the first laminated resin layer. 0.2 to 3.0 parts of silicone gum per 100 parts by weight of the resin component of the layer.
0 parts by weight and 0.05 to 2.0 parts by weight of silicone resin powder are blended.

As is clear from the description in the Examples section above, the composite biaxially stretched polypropylene resin film of the present invention having the above structure has a heat sealing temperature that does not melt the biaxially stretched polypropylene resin film layer. in,
In addition, the composite 2 of the present invention is equipped with a heat sealant layer that has both heat sealing performance that allows heat sealing in a short time and good slip properties, especially good slip properties at high temperatures. Packaging materials made of axially oriented polypropylene resin films have good sliding properties and detachability from metal guide plates and hot plates in overlap-type high-speed automatic packaging machines that have been developed in recent years. Not only hard carton boxes such as caramel individual packaging, but also soft carton packaging such as cigarette individual packaging, has no wrinkles or corners.
This results in a package with a tight feel and a good finish.

Claims (3)

[Claims] Claim 1: A base material layer made of a polypropylene resin film subjected to biaxial stretching, a first laminated resin layer laminated on one side of the base material layer, and a first laminated resin layer of the first laminated resin layer. In a composite biaxially stretched polypropylene resin film having a three-layer configuration with a second laminated resin layer laminated on the opposite base material layer surface, the resin component of the first laminated resin layer is
Ethylene-propylene with an ethylene component content of 0.5 to 8.0% by weight and a butene component content of 0.5 to 5.0% by weight
Consisting of a mixed resin of 30 to 70% by weight of a random copolymer of butene and 70 to 30% by weight of a butene monopolymer,
Further, the resin component of the second laminated resin layer is one or more butene-based copolymers selected from ethylene-butene copolymer, ethylene-propylene-butene copolymer, and propylene-butene copolymer. or, the second laminated resin layer is made of a mixed resin of the butene-based copolymer and polybutene and/or ethylene-propylene copolymer, and the content of the butene component in the resin component is 5 to 70. % by weight, and only in the first laminated resin layer, 2 parts by weight per 100 parts by weight of the resin component of the laminated resin layer.
Silicone gum made of a polysiloxane polymer with a viscosity of 107 centistokes or more at 5°C 0.2~
3.0 parts by weight and 0.05 to 2.0 parts of silicone resin powder
A composite biaxially oriented polypropylene resin film, characterized in that parts by weight are blended. Claim 2: Butene-1 in the first laminated resin layer
The MFR of the polymer is defined in JIS K6760.
Butene (melt flow rate) of 1 to 8 g/10 min.
1 polymer 30 to 90% by weight, also JIS K 67
MFR (melt flow rate) defined as 60 is 1
The composite biaxially stretched polypropylene resin film according to claim 1, comprising a mixture of 8 to 50 g/10 minutes of butene and 70 to 10% by weight of monopolymer. 3. The resin component in the second laminated resin layer is propylene-propylene containing a butene component of 5 to 50% by weight.
The composite biaxially stretched polypropylene resin film according to claim 1 or 2, comprising a butene copolymer.