JPH06107868A - Polyolefin resin film - Google Patents

Abstract

PURPOSE:To provide the title film having excellent transparency and good slipperiness and scratch resistance. CONSTITUTION:The film is made from a composition prepared by adding 0.005-2 pts.wt. crosslinked particles having a mean particle diameter of 0.4-7mum, made of a polymer prepared by copolymerizing as the principal components an acrylic monomer with a styrene monomer in a weight ratio of 0.1/0.9 to 0.9/0.1 to 100 pts.wt. polyolefin resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin film which is excellent in transparency, has good slipperiness and scratch resistance, has less soybean contamination during film formation, and has excellent film formation operability. .

[0002]

2. Description of the Related Art Conventionally, inorganic fine particles have been added as a method for improving the slipperiness and blocking resistance of a polyolefin resin film (for example, JP-B-52-16134, JP-B-42-24523 and JP-A-3). -99
38) and organic polymer fine particles added (for example, JP-A-49-11945 and JP-A-57-64).
522, JP-A-62-39219) and the like are known.

Of these methods, the method of using fine particles of an organic polymer is more useful than the method of using inorganic fine particles because a film having excellent transparency and scratch resistance can be obtained. However, organic polymer particles,
Since the heat resistance is inferior to that of the inorganic fine particles, the method of using the fine particles of the organic polymer is, for example, the contamination by the deteriorated material at the die outlet during the film formation is large and it is necessary to increase the number of die lip cleanings. There was a problem such as reduced operability.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and its object is to provide excellent transparency, good blocking resistance, scratch resistance, and slipperiness. (EN) It is intended to provide a polyolefin resin film which has little die contamination during film formation and is excellent in film forming operability.

[0005]

The polyolefin resin film of the present invention comprises an acrylic monomer and a styrene monomer which are composed of the following copolymerization proportions having an average particle diameter of 0.4 to 7 μm with respect to 100 parts by weight of the polyolefin resin. A polyolefin resin film comprising a composition containing 0.005 to 2 parts by weight of crosslinked particles of a polymer copolymerized with a monomer as a main component. Acrylic monomer / Styrene monomer = 0.1 / 0.9
~ 0.9 / 0.1 (weight ratio)

The polyolefin resin in the present invention means
Propylene, ethylene, butene, 4-methylpentene-
A homopolymer or copolymer such as 1 or a mixture of these polymers. The crosslinked particles in the present invention have an acrylic monomer and a styrenic monomer in a polymer weight ratio of 0.
The copolymer must be contained as a main component in a ratio of 1 / 0.9 to 0.9 / 0.1.

In the case of non-crosslinked particles, the heat resistance of the particles is low, so that, for example, deterioration products accumulate at the die outlet during film formation,
Since streaky scratches occur on the film, it is necessary to increase the number of times the die lip is cleaned to remove accumulated deterioration products. Film operability (hereinafter, simply referred to as film operability)
Is reduced, which is not preferable.

If the acrylic monomer / styrene monomer content is less than 0.1 / 0.9, the transparency of the film is lowered, which is not preferable. On the other hand, if the acrylic monomer / styrene monomer exceeds 0.9 / 0.1, the heat resistance is low and the film forming operability is deteriorated even with crosslinked particles, which is not preferable. 0.2 / 0.8 to 0.8 / 0.2 is more preferable. Here, as the acrylic monomer, acrylic acid, acrylic acid such as methyl acrylate, ethyl acrylate, and butyl acrylate, or an ester derivative of acrylic acid, methacrylic acid, methyl methacrylate, or methacrylic acid is used. Examples thereof include methacrylic acid or ester derivatives of methacrylic acid such as ethyl acidate and butyl methacrylate. Even if these monomers are one kind,
You may use 2 or more types together. Further, as long as it is a small amount, a metal salt of acrylic acid or methacrylic acid, an amide derivative, an ester derivative having a special structure such as hydroxylethyl ester or dimethylaminoethyl ester may be used.

Examples of the styrene-based monomer include styrene such as styrene, methylstyrene and α-methylstyrene, or a derivative thereof.

Further, the above copolymer has a total weight of 20
As long as it is not more than weight%, it may be a copolymer of polymerizable vinyl monomers such as vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, and methacrylonitrile.

Examples of the cross-linking agent include, but are not limited to, divinylbenzene, ethylene glycol diacrylate and dimethacrylate.

The method for making the polymer into fine particles is not limited, but a method such as emulsion polymerization or suspension polymerization is used.
A method of directly forming fine particles during polymerization is suitable. When this method is adopted, a means of copolymerizing a polar monomer having a special structure is used in order to impart self-emulsifying property to the polymer, but there is no limitation to use these means. Absent. Rather, it is the preferred embodiment. The shape of the polymer fine particles is not particularly limited, but is preferably substantially spherical.

The average particle size of the crosslinked particles must be in the range of 0.4 to 7 μm. If it is less than 0.4 μm, the effect of improving the slipperiness is reduced, which is not preferable. Conversely, 7 μm
When it exceeds, the effect of improving the slipperiness is saturated and the transparency is deteriorated, which is not preferable. The particle size distribution of the crosslinked particles is
The sharpness is preferable in terms of satisfying transparency, slipperiness, and blocking resistance. The average particle size of the polymer fine particles is obtained by taking a photograph with a scanning electron microscope, measuring the Feret diameter in the horizontal direction using an image analyzer, and displaying the average value.

The blending ratio of the polyolefin resin used in the present invention and the crosslinked particles is such that polyolefin resin 1
0.005 to 2 parts by weight of cross-linked particles with respect to 00 parts by weight,
It is preferably 0.01 to 1 part by weight. If the amount of the crosslinked particles is less than 0.005 part by weight, it is impossible to impart the slip property and the blocking resistance to the film, while if it exceeds 2 parts by weight, the slip property and the blocking resistance are sufficiently imparted. However, it is not preferable because the transparency of the film is significantly impaired.

The optimum values of the average particle size and blending ratio of the crosslinked particles vary greatly depending on the type of polyolefin resin, the thickness and structure of the film, the presence or absence of stretching, etc. It is better to set it arbitrarily.

In the present invention, organic or inorganic fine particles other than the crosslinked particles may be used in combination as long as the effects of the present invention are not impaired. In the present invention, there is no limitation to take measures such as using a lubricant such as higher fatty acid amide, higher fatty acid ester, wax, and metallic soap together to improve slipperiness. Rather, the combined use of these lubricants is the preferred embodiment.

There are no restrictions on the combined use of stabilizers, antistatic agents, ultraviolet absorbers, processing aids, plasticizers and the like which are usually used for polyolefin resins.

The method for mixing the above-mentioned crosslinked particles, additives and the like is not particularly limited, but kneaded pellets with a mixer such as a V type blender, a screw type blender, a dry blender, a ribbon blender or a Henschel mixer. It is common to change.

The method of the present invention can be applied to an unstretched cast film that has been simply extruded, or to a stretched film that has been uniaxially or biaxially stretched from the casting film. Further, it can be applied to both a single layer structure and a multilayer structure composed of two or more layers. In the case of a multi-layer structure, the above-mentioned crosslinked particles are generally added to the surface layer, but not limited thereto.

Further, it is a preferred embodiment that the film of the present invention is subjected to a surface treatment such as a corona discharge treatment plasma treatment, an ultraviolet irradiation treatment or the like for surface activation treatment to improve adhesiveness.

[0021]

EXAMPLES The present invention will be described below based on examples. The measuring method used in the examples is as follows.

(1) Haze value Measured by Toyo Seiki Haze Tester J according to JIS-K6714.

(2) Coefficient of friction Measured by ASTM-D1894 at 20 ° C. × 65% RH.

(3) Scratch resistance According to JIS-L0823-1971, 5% under a load of 200 gf by a dyeing fastness friction tester manufactured by Toyo Seiki.
The friction test was performed 0 times, the haze value before and after the test was measured, and the degree of increase of the haze value by the friction test was measured. The smaller the degree of increase, the better the scratch resistance.

(4) Film-forming operation coefficient: Using a twin-screw extruder equipped with a nozzle having a diameter of 4 mmφ, the absorption composition (in the case of a multilayer film, the polymer composition used for the surface layer is used) at a temperature of 270 ° C. and 12 kg / hr. Melt extrusion was carried out for 8 hours at the discharge amount, and the growth degree (length: mm) of the thermally deteriorated substance deposited on the nozzle surface was displayed. The lower the growth rate, the better the film forming operability.

Example 1 As a base layer (A), a mixed composition 10 comprising 90% by weight of a propylene-ethylene copolymer having an ethylene content of 0.5% by weight and 10% by weight of a petroleum resin (trade name Alcon P-115).
The composition was such that 0.3 part by weight of glycerin resin acid ester and 0.3 part by weight of erucic acid amide were mixed with 0 part by weight.

On the other hand, the butene content of the surface layer (B) is 2
100 parts by weight of a 3% by weight propylene / butene-1 copolymer (melt index 6.0 g / 10 min), a cross-linked acrylic-styrene-based copolymer having an almost monodisperse particle size distribution with an average particle size of 1.5 μm. 0.25 part by weight of coalesced particles [methyl methacrylate / n-butyl acrylate / styrene / divinylbenzene = 36/27/36/1 (weight ratio)], 0.5 part by weight of glycerin fatty acid ester, and hydroxy stearoamide 0. A composition was used in which 5 parts by weight were mixed, melt-extruded at 180 ° C., and pelletized. The A
The layer and B layer compositions were melt extruded from two extruders to give a B / A / B three layer unstretched film. The unstretched film was stretched in the longitudinal direction at 130 ° C. at a rate of 4 or 5 and further in the transverse direction at a rate of 8 times, and corona discharge treatment was applied to both surfaces to a thickness of 25 μm (thickness ratio 5: 90: 5). To obtain a biaxially stretched film. The characteristic values of the obtained film are shown in Table 1.

The film obtained in this example has transparency,
It has excellent slipperiness and scratch resistance, and also has a good operation index during film formation.

Comparative Example 1 Instead of the crosslinked acryl-styrene copolymer particles, crosslinked styrene polymer particles having an average particle diameter of 1.5 μm and having a substantially monodispersed particle size distribution [styrene / divinylbenzene = 9]
9/1 (weight ratio)], the characteristics of the film obtained by the same method as in Example 1 are shown in Table 1.

The film obtained in this Comparative Example has a good operation index and scratch resistance during film formation, but is inferior in transparency.

Comparative Example 2 Instead of the crosslinked acrylic-styrene copolymer particles, crosslinked acrylic polymer particles having an average particle diameter of 1.5 μm and having a substantially monodispersed particle size distribution [methylmethacrylate / n-butylacrylate]. / Ethylene glycol dimethacrylate residue = 60/39/1 (weight ratio)], the properties of the film obtained by the same method as in Example 1 are shown in Table 1.
The film obtained in this comparative example is excellent in transparency, slipperiness, and scratch resistance, but the operation index during film formation is inferior.

Comparative Example 3 The procedure of Example 1 was repeated, except that spherical silica having an average particle size of 1.5 μm and having a substantially monodispersed particle size distribution was used instead of the crosslinked acrylic-styrene copolymer particles. The characteristics of the film are shown in Table 1.

The film obtained in this Comparative Example has a good operation index at the time of film formation, but is inferior in transparency and scratch resistance.

Example 2 Crosslinked acrylic-styrene copolymer particles having an average particle size of 2.2 μm [methyl methacrylate / n-butyl acrylate / styrene / divinylbenzene = 20/10/69
1/1 (weight ratio)] 0.1 wt% polypropylene having a melt index of 2.5 g / 10 min is used at a resin temperature of 27
A sheet having a thickness of 0.72 mm was obtained by performing melt extrusion at 0 ° C. and quenching with a cooling roll at 30 ° C. The obtained sheet was stretched 4.5 times in the longitudinal direction at a stretching temperature of 40 ° C. by utilizing the roll peripheral speed difference of the longitudinal stretching machine, and subsequently stretched by a tenter type stretching machine at a stretching temperature of 155 ° C. in the transverse direction 8 times. It was stretched. Then, heat treatment is performed at 160 ° C. to obtain a thickness of about 20 μm
After forming the axially stretched film, one side was subjected to corona treatment.
The characteristic values of the obtained film are shown in Table 1. The film obtained in this example is excellent in transparency, slipperiness, and scratch resistance, and also has a good operation index during film formation.

Comparative Example 4 In place of the crosslinked acrylic-styrene copolymer particles, crosslinked styrene copolymer particles having an average particle diameter of 2.2 μm (styrene / divinylbenzene = 99/1 (weight ratio)) were used. The characteristics of the film obtained in the same manner as in Example 2 are shown in Table 1.
Shown in. The film obtained in this comparative example has a good operation index during film formation, but has poor transparency.

Comparative Example 5 Example 5 was repeated except that 0.05% by weight of nylon 6 having an average particle diameter of 5 μm and amorphous silica having an average particle diameter of 3 μm were mixed in place of the crosslinked acrylic-styrene copolymer particles. The characteristics of the film obtained by the same method as in 2 are shown in Table 1.

The film obtained in this Comparative Example has good film characteristics such as transparency, slipperiness and scratch resistance.
The operation index of film formation is extremely inferior.

Example 3 80% by weight of an isotactic polybutene-1-ethylene copolymer (ethylene content: 3.5% by weight), 10% by weight of a propylene-butene 1 copolymer and 10 of a propylene-ethylene copolymer. 1% by weight of an ethylene oxide adduct of alkylamine as an antistatic agent is mixed with a mixed composition of 1% by weight to obtain a film material (A) for a base layer. As the coating film material (B), propylene-butene 1 copolymer (butene content 12% by weight) and propylene-ethylene copolymer (ethylene content 4.5%) are used.
50% by weight), and cross-linked acryl-styrene copolymer particles having an average particle diameter of 3.5 μm (methyl methacrylate / n-butyl acrylate / styrene / divinylbenzene = 20/10 /). 6
9/1 (weight ratio)] A mixture of 0.2% by weight is used.

The above materials (A) and (B) are melt-extruded, laminated in a molten state, and then cooled by a cooling roll at 25 ° C. to make the thickness of (B) layer / (A) layer / (B) layer. Ratio is 15
A laminated unstretched film having a thickness of / 75/15 of 720 μm was obtained. The unstretched film was vertically stretched at 125 ° C. to 4.0
The film was biaxially stretched twice in the transverse direction and 4.5 times in the transverse direction to obtain a 40 μm biaxially stretched film. The properties of the obtained film are shown in Table 1.

The film obtained in this example has excellent film characteristics such as transparency, slipperiness and scratch resistance, and also has a good film-forming operation index.

Comparative Example 6 The characteristics of the film obtained in the same manner as in Example 3 were changed except that 0.4% by weight of amorphous silica having an average particle diameter of 3.5 μm was added instead of the crosslinked acrylic-styrene copolymer particles. It shows in Table 1. The film obtained in this comparative example is inferior in slipperiness.

Comparative Examples 7 to 8 Instead of the crosslinked acryl-styrene copolymer particles, the stellene particles having an average particle diameter of 3.5 μm (composition is Comparative Example 1).
Table 1 shows the characteristics of the film obtained by the same method as in Example 3 except that the same) and acrylic particles (the composition is the same as in Comparative Example 2) are used.

The film using styrene particles has transparency, and the film using acrylic particles has a poor operation index during film formation.

Example 4 Propylene-ethylene random copolymer having a melt index of 5 g / 10 min (ethylene content 5% by weight) 10
0 parts by weight of 0.25 parts by weight of stearic acid amide and 0.3 parts by weight of crosslinked acrylic-styrene copolymer particles having an average particle size of 5 μm (composition is the same as in Example 3) were mixed and melted at a resin temperature of 250 ° C. The film was extruded and rapidly cooled with a cooling roll at 25 ° C. to obtain a cast film having a thickness of 40 μm.
Table 1 shows the properties of the obtained cast film.

The film obtained in this example has transparency,
It has excellent slipperiness and scratch resistance, and also has a good operation index during film formation.

Comparative Example 9 The casting film characteristics obtained in the same manner as in Example 4 are shown except that 0.3 parts by weight of spherical violite having an average particle size of 5.0 μm is blended in place of the crosslinked acrylic-styrene copolymer particles. Shown in 1.

The film obtained in this comparative example is inferior in transparency and scratch resistance.

Example 5 100 parts by weight of linear low-density polyethylene obtained by octene copolymerization with a melt index of 2.0 g / 10 min was added to 0.25 part by weight of amide oleate and a crosslinked acrylic-styrene copolymer having an average particle size of 3.5 μm. 0.40 parts by weight of polymer particles are blended,
A casting film having a thickness of 60 μm was obtained by the same method as in Example 4. The properties of the obtained film are shown in Table 1.

The film obtained in this example is excellent in transparency, slipperiness and scratch resistance, and also has a good operation index during film formation.

Comparative Example 10 A casting film obtained in the same manner as in Example 5 except that 0.40 parts by weight of particles of diatomaceous earth having an average particle size of 3.5 μm were mixed in place of the crosslinked acrylic-styrene copolymer particles. The physical properties of are shown in Table 1.

The film obtained in this Comparative Example had a good operation index during film formation, but was inferior in transparency, slipperiness and scratch resistance.

[0052]

[Table 1]

[0053]

INDUSTRIAL APPLICABILITY According to the present invention, a cross-linked particle of a copolymerized polymer containing an acrylic monomer having a specific composition and an average particle diameter as a main component and a styrene monomer as a main component is used in a specific amount of a polyolefin resin. It is highly practicable because it has excellent transparency, a film with good slipperiness and scratch resistance is obtained, and the die is not contaminated during film formation and has excellent film forming operability. .

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C08L 33:00) (C08L 23/02 25:14) (72) Inventor Yasushi Furuyu Inuyama City, Aichi Prefecture Kizu character Maebata 344 Toyobo Co., Ltd. Inuyama factory

Claims (1)

[Claims] 1. An acrylic monomer and a styrene monomer having an average particle diameter of 0.4 to 7 μm and having the following copolymerization ratios based on 100 parts by weight of a polyolefin resin are copolymerized as main components. A polyolefin resin film comprising a composition containing 0.005 to 2 parts by weight of crosslinked polymer particles. Acrylic monomer / Styrene monomer = 0.1 / 0.9
~ 0.9 / 0.1 (weight ratio)