KR101892870B1 - Polyolefin resin composition for matt film and film produced with the same - Google Patents

Abstract

The present invention relates to a polyolefin resin composition for a matt film and a film produced from the polyolefin resin composition for the matt film. Provided is a polyolefin resin composition comprising: 39.95 to 60 wt% of a polyethylene resin including 48 to 52 wt% of an ethylene homopolymer (A) having a melt index 10 to 50 g/10 mins when measuring with a load of 2.16 kg at 190°C in accordance with ASTM D1238, and 48 to 52 wt% of a copolymer (B) of ethylene or α-olefin having 3 to 20 carbon atoms; 39.95 to 60 wt% of a homo-polypropylene resin or a random polypropylene resin; and 0.005 to 0.05 wt% of peroxide. The polyethylene resin has a melt index 0.1 to 0.4 g/10 mins when measuring with a load of 2.16 kg at 190°C in accordance with ASTM D1238. Further, a film produced from the polyolefin resin composition of the present invention, as a matt film, exhibits a high haze value of 80% or more, and has excellent external physical properties by having less than 0.5 spot/400 cm^2 as a total number of shiny spots and silver spots.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyolefin resin composition for a matte film and a film produced therefrom,

The present invention relates to a polyolefin resin composition having excellent matt characteristics and a film produced therefrom. More particularly, the present invention relates to a polyolefin resin composition excellent in lightfastness when applied to an outer layer (skin layer or outer layer) And a polyolefin resin composition excellent in film appearance and a film produced therefrom.

BACKGROUND OF THE INVENTION Polyolefin resins are widely used for films for industrial and household products due to their excellent mechanical and electrical properties. Particularly, matte films having a low surface gloss and showing a smooth surface texture are widely used.

Such a matte film is generally produced by forming a sheet by a multi-layer T-die casting method, and then stretching the sheet longitudinally and transversely in a partially molten state at a temperature lower than the melting temperature by applying heat, a diffuse reflection due to surface irregularities is generated so as to exhibit a matte property on a skin layer, and a polypropylene resin composition is generally used as a core layer. The biaxial stretching method shows a very high rigidity as compared with a film formed by the T-die casting method in the case of film production and is widely used in various fields such as food packaging and industrial use because of its excellent transparency and moisture barrier property.

The matte film is mainly composed of haze and gloss, and the shiny spot (or bright spot) and the PP film layer are not exposed because the matte film layer on the surface is not fully stretched and the PP film layer of the middle layer is exposed. But the haze of the matte film layer is not uniform and is evaluated as a property such as a silver spot having relatively low matt characteristics. The higher the haze, the lower the gloss, the better the matte property, and the smaller the shiny spot and bright spot, It is estimated that the uniformity of quality is high.

Conventionally, as a method for producing a matte film, there have been known a method of polishing a surface of a film with a metal powder to form a scratched surface, and an embossing method of processing a film with a roll having projections and depressions. However, Cracks are formed on the surface of the film or the size of the grooves is uneven, making it difficult to produce a uniform film. Moreover, this method has a disadvantage that the mechanical properties are poor and easily torn.

In order to solve these problems, various methods utilizing the difference in flowability, shrinkage ratio and refractive index between mixed resins, which are characteristics of a resin mixture having incompatibility, are presented.

U.S. Patent No. 5,366,796 proposes a method of obtaining a matte film through a biaxial stretching process using a resin composition obtained by mixing a polypropylene resin and a high-density polyethylene resin as a surface layer. However, the haze is as low as 40 or more, and there is no mention of film appearance quality such as shiny spot or sliver spot.

Korean Patent No. 10-0557566 discloses an ethylene-alpha olefin copolymer resin or an ethylene polymerization resin, which is a copolymer resin of alpha-olefin and ethylene having not more than 10 carbon atoms, an ethylene-propylene copolymer containing ethylene and an ethylene- Propylene copolymer and a method of molding it into a matte film by a blown film method. However, there is no mention of film appearance quality such as film haze and shiny or silver spot as a method for improvement of impact strength and tear strength.

An object of the present invention to solve the above problems is to provide a polyolefin resin composition for a matte film excellent in haze and excellent in appearance properties due to low shiny spot and silver spot.

Another object of the present invention is to provide a matte film made of a polyolefin resin composition.

According to an aspect of the present invention,

48 to 52 wt% of an ethylene homopolymer (A) having a melt flow index of 10 to 50 g / 10 min at 190 DEG C and 2.16 kg of ASTM D1238 and 48 to 52 wt% of an ethylene /? - olefin copolymer (B) % Of a polyethylene resin;

39.95 to 60% by weight homopolypropylene or random polypropylene resin; And 0.005 to 0.05% by weight peroxide; Wherein the polyolefin resin composition comprises:

Wherein the polyethylene resin has a melt flow index of 0.1 to 0.4 g / 10 min at 190 占 폚 and 2.16 kg of ASTM D1238.

Further, it is intended to provide a film made of the polyolefin resin composition.

The polyolefin resin composition having excellent non-light-emitting properties according to the present invention has excellent matt appearance characteristics when applied to a skin layer or an outer layer at the time of production of a film, and has a small shiny spot and silver spot and is excellent in film appearance.

Hereinafter, the present invention will be described in more detail.

48 to 52 wt% of an ethylene homopolymer (A) having a melt flow index of 10 to 50 g / 10 min at 190 DEG C and 2.16 kg of ASTM D1238 and 48 to 52 wt% of an ethylene /? - olefin copolymer (B) % Of a polyethylene resin;

39.95 to 60% by weight homopolypropylene resin or random polypropylene resin; And 0.005 to 0.05% by weight of a peroxide,

Wherein the polyethylene resin has a melt flow index of 0.1 to 0.4 g / 10 min at 190 占 폚 and 2.16 kg of ASTM D1238.

In addition, the film made of the polyolefin resin composition shows a high haze of 80% or more as a matte film, and the sum of the shiny spot and the sliver spot is less than 0.5 / 400 cm < ² >

In one embodiment of the present invention, the polyethylene resin may contain the ethylene homopolymer (A) in an amount of 48 to 52 wt%, and when the content of the ethylene homopolymer (A) is less than 48 wt% Is less than 80%, and when it exceeds 52% by weight, shiny spot and silver spot increase.

The ethylene homopolymer (A) has a melt flow rate (190 占 폚, 2.16 kg in ASTM D1238) of 10 to 50 g / 10 min, preferably 10 to 25 g / 10 min, more preferably 13 to 20 g / to be.

If the melt flow index of the ethylene homopolymer (A) is less than 10 g / 10 min, the haze of the film may be reduced to less than 80% And the quality of the appearance of the film may be problematic.

In one embodiment of the present invention, the polyethylene resin may contain ethylene or an? -Olefin copolymer (B) having 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms in an amount of 48 to 52% by weight, When the number of carbon atoms is more than 20, the reactivity is lowered and the resin production cost is greatly increased. If the content is less than 48% by weight, the haze is less than 80% and when the content is more than 52% by weight, the shiny spot and the silver spot are increased.

In one embodiment of the present invention, the polyolefin resin composition may include 39.95 to 60% by weight of a polyethylene resin comprising an ethylene homopolymer (A) and ethylene or an? -Olefin copolymer (B) having 3 to 20 carbon atoms have.

If the content of the polyethylene resin is less than 39.95% by weight or exceeds 60% by weight, the haze becomes less than 80%.

The polyethylene resin has a melt flow index (190 占 폚, 2.16 kg in ASTM D1238) of 0.1 to 0.4 g / 10 min, preferably 0.15 to 0.35 g / 10 min.

When the melt flow index is less than 0.1 g / 10 min, shiny spots and silver spots are increased. When the melt flow index exceeds 0.4 g / 10 min, the haze is reduced to less than 80%.

In one embodiment of the present invention, the polyolefin resin composition may include a homopolypropylene resin or a random polypropylene resin containing at least one selected from ethylene and butene-1.

The homopolypropylene resin or the random polypropylene resin may be contained in an amount of 39.95 to 60% by weight based on the total weight of the polyolefin resin composition. When the content is less than 39.95% by weight or exceeds 60% by weight, haze is less than 80% .

The homopolypropylene resin or the random polypropylene resin preferably has a melt flow index (230 DEG C, 2.16 kg of ASTM D1238) of 1 to 20 g / 10 min, more preferably 12 to 18 g / 10 min.

If the melt flow index is less than 1 g / 10 min, the haze is less than 80%, the processing load is high and the productivity is decreased. When the melt flow rate is more than 20 g / 10 min, shiny spot and silver spot are increased, Deep sea die cleaning cycle is short, which hinders productivity.

In one embodiment of the present invention, the polyolefin resin composition may include a peroxide.

If the content is less than 0.005% by weight, haze becomes less than 80%, and when it exceeds 0.05% by weight, shiny spot and silver spot are increased.

In one embodiment of the present invention, the polyethylene resin has a melt flow index (MI) of 21.6 kg / m < 2 > at a melt flow index measured at 190 DEG C and a load of 2.16 kg at a load of 21.6 kg The melt flow index ratio (MFRR), which is 2.16 kg, is 50-100.

If the melt flow index ratio is less than 50, the haze becomes less than 80%, and when it exceeds 100, the shiny spot and the silver spot increase.

The density of the polyethylene resin is the 0.950 ~ 0.965g / cm ³ are preferred, and the density can is 0.950g / cm ³ less than the haze is inferior to less than 80% decrease the matte properties of the film, 0.965g / cm ³ Excessive shiny and silver spots can cause problems in the appearance of the film.

In one embodiment of the present invention, the polyethylene resin composition may further include at least one selected from an antioxidant, a neutralizing agent, and a fluorine resin.

The antioxidant may be contained in an amount of 0.01 to 0.5 parts by weight, preferably 0.05 to 0.2 parts by weight, based on 100 parts by weight of the polyethylene resin composition.

If the content of the antioxidant is less than 0.01 part by weight, discoloration during storage and viscosity change during processing may occur. If the content of the antioxidant is more than 0.5 parts by weight, the mechanical properties of the resin may be deteriorated.

The neutralizing agent may be contained in an amount of 0.01 to 0.3 parts by weight, preferably 0.05 to 0.2 parts by weight, based on 100 parts by weight of the polyethylene resin composition.

If the content of the neutralizing agent is less than 0.01 parts by weight, discoloration and viscosity change during processing may occur. If the amount of the neutralizing agent is more than 0.3 parts by weight, changes in physical properties such as color and strength may occur.

The fluororesin may be contained in an amount of 0.01 to 0.2 parts by weight, preferably 0.05 to 0.1 parts by weight, based on 100 parts by weight of the polyethylene resin composition.

If the content of the fluorine resin is less than 0.01 parts by weight, the die build-up is severe and the die cleaning cycle is short, which may hinder productivity. If the fluorine resin content exceeds 0.2 parts by weight, the mechanical properties of the resin may be deteriorated.

Representative examples of the antioxidant include 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene (1,3,5- , 4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1,6-bis [3- (3,5- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamido] hexane), 1,6-bis [3- Butyl-4-hydroxyphenyl) propionamido] propane), tetrakis [methylene (3,5 4-hydroxyhydrocinnamate)] methane), bis (2,6-di-tert-butyl-4-hydroxyhydrocinnamate) Butyl-4-methylphenyl) pentaerythritol-di-phosphite), tris (2,4-di-tert- butylphenyl) pentaerythritol- ) Phosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol-di-phosphite (Bis (2,4-di-tert-butylphenyl) Pentraerythritol-di-phosphite) and the like.

Representative examples of such neutralizing agents may include calcium stearate, zinc stearate, magnesium aluminum hydroxycarbonate, zinc oxide and magnesium hydroxystearic acid or mixtures thereof.

The polyolefin resin composition according to the present invention can be used in both blown and cast film production methods, and can provide a film made of the polyolefin resin composition.

The film may be a matte film, preferably a haze of 80% or more, and a sum of a shiny spot and a silver spot is preferably 0.5 ea / 400 cm ^{2 or} less.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples so that those skilled in the art can easily carry out the present invention. The following examples are only illustrative of the present invention and do not limit the scope of protection of the present invention.

Example  1 to 7, Comparative Example  1 to 8

Polyethylene resin ( The first component )

Two-stage polymerization was carried out in two polymerization tanks connected in series by continuous slurry polymerization. The comonomer used is 1-butene. In the first polymerization reactor, only ethylene was fed as the monomer, and in the second polymerization reactor, ethylene and 1-butene were fed to polymerize.

(Blend ratio, B / R) of the ethylene homopolymer (A) obtained in the first polymerization reactor, the melt flow index (1-stage MI) at 190 ° C, the ratio (B) The ratio of the copolymer (B) of 1-butene is shown in Table 1, and the melt flow index (MI), the melt flow index ratio (MFRR) and the density of the first component in which A and B are mixed are shown in Table 1.

0.025 part of Irganox-1010 (Tetrakisethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane) as an antioxidant, 0.025 part of Irgafos-168 (Tris (2,4- t-butylphenyl) phosphite, and 0.1 part by weight of calcium stearate as a neutralizing agent were mixed in a Henschel mixer, and then granulated in a pellet form at 200 ° C using a 50Φ twin-screw extruder.

1st , 2, Ternary Kneading extrusion

The above-prepared polyethylene resin (first component), Hanwha total homopolypropylene resin or random polypropylene resin (second component), peroxide 2,5-dimethyl-2,5-di (tert- butylperoxy hexane (third component) were mixed in the weight percentages shown in Table 1, and then granulated in the form of pellets at 200 占 폚 using a 50? twin-screw extruder.

In Examples 1 to 6 and Comparative Examples 1 to 8, the polypropylene resin of polypropylene resin is RJ773, and the polypropylene resin of Example 7 is HF429.

Biaxially  oriented polypropylene ( BOPP ) Film processing

A / B two layers of BOPP film were processed. The core layer (B) is HU300 (2.16 kg load, melt flow index at 230 캜 is 3 g / 10 min.), which is a Hanwha total homopolypropylene, and the skin layer (A) Kneaded and extruded.

Melt flow index (Melt Index, MI)

Measured according to ASTM D1238 at 190 占 폚 at 2.16 kg or 230 占 폚 at 2.16 kg.

Melt flow index  The Melt Flow Rate Ratio, MFRR )

MI 21.6 (21.6 kg load, melt flow index at 190 캜) / MI 2.16 (2.16 kg load, melt flow index at 190 캜)

density

Measured according to ASTM D1505.

Haze

And measured according to ASTM D1003.

Gloss

Measured according to ASTM D2477. (45 DEG)

Shiny spot

The matt film layer on the surface was not completely stretched so that the PP film layer of the middle layer was exposed and the number of the sparkles was measured visually in the light of a fluorescent lamp.

Silver spot

The PP film layer was not exposed, but the haze of the matte film layer was not uniform, and the number of the samples was visually observed in the light of a fluorescent lamp in a part where the matte property was relatively poor.

Property Unit Example One 2 3 4 5 6 7 1st
ingredient 1st stage MI 190 < 0 > C, g / 10 min 15 25 45 15 15 15 15 1st stage B / R wt% 50 51 48 50 50 50 50 MI 2.16 kg 190 < 0 > C, g / 10 min 0.35 0.25 0.2 0.35 0.35 0.35 0.35 MFRR - 65 70 70 65 65 65 65 Density g / cm ³ 0.962 0.960 0.959 0.962 0.962 0.962 0.962 Resin blend wt% 49.99 49.99 49.99 54.99 44.99 49.99 49.99 Second
ingredient MI 230 deg. C, g / 10 min 18 18 18 18 18 18 8 C2 wt% 3 3 3 3 3 3 0 Resin blend wt% 49.99 49.99 49.99 49.99 54.99 49.99 49.99 Third
ingredient Peroxide wt% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 film
Properties Matt skin layer ㎛ 2 2 2 2 2 2 2 Haze % 85 88 88 87 86 89 85 Gloss % 8.1 8.3 8.4 7.9 8.5 7.9 8 Shiny spot ea / 400
cm ² 0.2 0.1 0.1 0.2 0.1 0.1 0.2 Silver spot ea / 400
cm ² 0.1 0.1 0.2 0.2 0.2 0.1 0.1

Property Unit Comparative Example One 2 3 4 5 6 7 8 1st
ingredient 1st stage MI 190 < 0 > C, g / 10 min 130 5 25 25 1000 140 15 15 1st stage B / R wt% 50 50 56 46 49 50 50 50 MI 2.16 kg 190 < 0 > C, g / 10 min 0.35 0.35 0.18 0.2 0.05 1.7 0.35 0.35 MFRR - 80 45 90 60 160 60 65 65 Density g / cm ³ 0.962 0.962 0.959 0.960 0.956 0.962 0.962 0.962 Resin blend wt% 49.99 49.99 49.99 49.99 49.99 49.99 29.99 50 Second
ingredient MI 230 deg. C, g / 10 min 18 18 18 18 18 18 18 18 C2 wt% 3 3 3 3 3 3 3 3 Resin blend wt% 49.99 49.99 49.99 49.99 49.99 49.99 69.99 50 Third
ingredient Peroxide wt% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0 film
Properties



Matt skin layer ㎛ 2 2 2 2 2 2 2 2 Haze % 83 75 87 78 81 72 65 68 Gloss % 8.2 8.9 7.9 8.3 8.1 8.6 8.9 8.8 Shiny spot ea / 400 cm ² 0.6 0.2 1.4 0.2 3.6 0.2 0.1 0.1 Silver spot ea / 400 cm ² 0.5 0.1 2.5 0.2 4.2 0.1 0.1 0.2

As shown in Table 1, the BOPP film properties using the polyolefin resin composition knitted in the twin-screw extruder including the first, second and third components of Examples 1 to 7 of the present invention as a skin layer had haze of 80% or more , The gloss is less than 10%, and the sum of the shiny spot and the silver spot is less than 0.5ea / 400 cm 2, which shows excellent matt film properties.

In Comparative Example 1, the sum of shiny spots and silver spots was 0.5 (melt flow index (MI) at 190 占 폚) of 1 st MI of the first component (2.16 kg of ethylene homopolymer ea / 400 cm 2. In Comparative Example 2, the first stage MI of the first component is as low as less than 10 g / 10 min, and the melt flow index ratio (MFRR) is as low as less than 50, so that the haze is less than 80%. In Comparative Example 3, the B / R ratio of the first component was more than 52 wt%, the shinny spot number exceeded 0.5 ea / 400 cm 2, and Comparative Example 4 was superior to the first component B / R (Blend ratio) is less than 48% by weight and Haze is less than 80%. In Comparative Example 5, the melt flow index ratio (MFRR) was more than 100, the MI of the first component was lower than 0.1 g / 10 min, and the shiny spot number exceeded 0.5 ea / The MI of the first component is higher than 0.5 g / 10 min and Haze is less than 80%. In Comparative Example 7, the haze of the first component was lower than 40% by weight and the haze of the Comparative Example 8 was lower than 80%.

Claims (9)

48 to 52% by weight of an ethylene homopolymer (A) having a melt flow index (190 DEG C, 2.16 kg in ASTM D1238) of 10 to 50 g / 10 min and 48 to 52% by weight of an ethylene /? - olefin copolymer 39.95 to 60% by weight of a polyethylene resin containing% by weight;
39.95 to 60% by weight homopolypropylene resin or random polypropylene resin; And
0.005 to 0.05% by weight of peroxide; Wherein the polyolefin resin composition comprises:
Wherein the polyethylene resin has a melt flow index (190 占 폚, 2.16 kg in ASTM D1238) of 0.1 to 0.4 g / 10 minutes.
The method according to claim 1,
Wherein the random polypropylene resin comprises at least one selected from ethylene and butene-1.
The method according to claim 1,
Wherein the homopolypropylene resin or the random polypropylene resin has a melt flow index (230 占 폚, 2.16 kg in ASTM D1238) of 1 to 20 g / 10 minutes.
The method according to claim 1,
Wherein a melt flow index ratio (MI: 21.6 kg / MI: 2.16 kg) of the polyethylene resin is 50 to 100. The polyolefin resin composition according to claim 1,
The method according to claim 1,
Wherein the polyethylene resin has a density of 0.950 to 0.965 g / cm < ^{3 &} gt ;.
The method according to claim 1,
Wherein the polyolefin resin composition further comprises at least one selected from the group consisting of 0.01 to 0.5 parts by weight of an antioxidant, 0.01 to 0.3 parts by weight of a neutralizing agent and 0.01 to 0.2 parts by weight of a fluorine resin based on 100 parts by weight of the polyolefin resin composition.
A film made from the polyolefin resin composition of any one of claims 1 to 6.
8. The method of claim 7,
Wherein the film has a haze of 80% or more.
8. The method of claim 7,
Wherein the film has a sum of a shiny spot and a silver spot of less than 0.5 ea / 400 cm < ^{2 &} gt ;.