KR20190123159A - Polypropylene resin composition for thermal adhesion film and polypropylene thermal adhesion film - Google Patents

Abstract

The present invention relates to a polypropylene resin composition for a thermal adhesive film, which comprises: (a) Terpolymers of ethylene, propylene and butenes; (b) a propylene-alphaolefin copolymer; and (c) an ethylene-octene rubber copolymer having 1-octene content of 20 to 30% and density of 0.900 to 0.910, wherein the polypropylene resin composition shows the melt index of 1 to 10 g/min, the melting temperature of 120 to 135°C, the melting strength of 0.1 to 0.2 N, and the thermal adhesive initiation temperature of 105°C or less and the content of the fraction soluble in xylene at room temperature is less than 5 wt%. The polypropylene resin composition of the present invention is possible to provide a polypropylene thermal adhesive film having excellent transparency and processability and excellent quality.

Description

POLYPROPYLENE RESIN COMPOSITION FOR THERMAL ADHESION FILM AND POLYPROPYLENE THERMAL ADHESION FILM}

The present invention relates to a polypropylene resin composition for a heat-adhesive film and a polypropylene heat-adhesive film, and more particularly, to a polypropylene resin composition for heat-adhesive film with improved transparency and processability, and a polypropylene heat-adhesive film prepared by such a composition. It is about.

Polypropylene thermal adhesive films are widely applied as thermal adhesive protective films applied to the inner surface of food or pharmaceutical packaging. More specifically, the thermal adhesive protective film is applied to the inner surface of the food or drug packaging to protect the food or drug while at the same time serves to seal the food or drug to the inner film facing each other by heat.

In order to increase the production speed during packaging, there is a method of reducing the thermal bonding time by increasing the thermal bonding temperature or lowering the thermal bonding temperature of the resin used in the thermal bonding layer. It is preferable to use a resin having a bonding temperature. In particular, a phenomenon in which the extruded film width becomes narrower than the extruder die width during packaging and a phenomenon in which the width of the film is not uniform occurs, so that high-speed processing is difficult.

In order to solve this problem, Japanese Patent Laid-Open No. 45-33298 discloses a technique for improving the processing speed by adding 5 to 15 wt% of a low density polyethylene having a density of 0.917 to 0.930 to a polypropylene resin composition. There is a lot of problems with poor transparency.

Korean Patent Publication No. 2001-0006497 discloses a method for controlling the melt flow rate ratio and the intrinsic viscosity ratio of an olefin copolymer, a homopolymer, and an ethylene-propylene copolymer, but the thickness of the olefin copolymer, the homopolymer, and the ethylene-propylene copolymer is insufficient. There is a problem that is difficult to apply for thick products.

Korean Patent Publication No. 2009-0057617 proposes a method for producing highly transparent polypropylene by increasing the dispersibility of vinyl cyclic saturated hydrocarbon, but the catalyst development should be prioritized and the polymerization process should be added. There is a difficult problem.

Korean Patent Publication No. 2007-0136526 discloses a heat-sealing film for food packaging obtained using a polypropylene terpolymer containing ethylene and butene. However, the polypropylene thermocompression film produced by such a technique has a problem that the thermal bonding temperature is improved but the amount of the blocking agent is added and transparency is inferior.

The present invention is to solve the problems of the above-described prior art, one object of the present invention is to provide a polypropylene resin composition excellent in transparency and processability at a wide range of temperatures.

Another object of the present invention is to provide a polypropylene thermal adhesive film excellent in transparency and processability formed from the polypropylene resin composition.

One aspect of the present invention for solving the above problems,

Terpolymers of ethylene, propylene and butene;

Propylene-alphaolefin copolymers; And

An ethylene-octene rubber copolymer having a 1-octene content of 20 to 30% and a density of 0.900 to 0.910,

Where the melt index of 1-10 g / min, the melting temperature of 120-135 ° C., the melt strength of 0.1N-0.2N, the thermal bonding initiation temperature of 105 ° C. or less and the content of fractions soluble in xylene at room temperature It is related with the polypropylene resin composition for heat adhesive films, which is less than 5 weight%.

The ethylene-propylene-butene terpolymer includes 0.5 to 3 wt% of ethylene derived units, 10 to 15 wt% of butene derived units and the balance of propylene derived units, and a melt index of 1.0 to 10.0 g / It is 10 min (230 degreeC), and melting temperature is 120-135 degreeC.

The propylene / alphaolefin copolymer has a unit derived from 0.5 to 10% by weight of alpha olefin, has a melt index of 1.0 to 10.0 g / 10 min (230 ° C.), and a density of 0.89 to 0.91 g / cm 3.

The propylene / alphaolefin copolymer may be a heterophasic propylene / alphaolefin copolymer.

The composition of the present invention is 80 to 90% by weight of the terpolymer of ethylene, propylene and butene; 1 to 10% by weight of propylene-alphaolefin copolymer; And (c) 1 to 10% by weight of ethylene-octene rubber copolymer.

Another aspect of the present invention relates to a polypropylene heat adhesive film formed from the polypropylene resin composition of the present invention, which film may be applied as a heat adhesive protective film to food or pharmaceutical packaging.

According to the present invention, it is possible to provide a polypropylene resin composition having excellent transparency and improved workability in a wide temperature range.

In addition, the polypropylene resin composition of the present invention can provide a polypropylene heat-adhesive film excellent in processability and transparency while also excellent in printability, moldability, laminate properties, and the like.

Such polypropylene thermal adhesive films can be advantageously applied as heat adhesive protective films in food or pharmaceutical packaging.

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

Polypropylene resin composition for heat adhesive film of one embodiment of the present invention

(a) terpolymers of ethylene, propylene and butene;

(b) propylene-alphaolefin copolymers; And

(c) an ethylene-octene rubber copolymer having a 1-octene content of 20 to 30% and a density of 0.900 to 0.910,

Where the melt index of 1-10 g / min, the melting temperature of 120-135 ° C , the melt strength of 0.1N-0.2N , the thermal bonding initiation temperature of 105 ° C or less and the content of fractions soluble in xylene at room temperature It is characterized by less than 5% by weight.

Such polypropylene resin compositions include terpolymers of propylene, ethylene and butene as polypropylene resins, with at least 90 to 99.5 weight percent units derived from propylene and 0.5 to 10 derived from C4-C10 alpha olefins. Propylene-alpha olefin copolymers having weight percent units. As a result, the heat-adhesive film formed of the polypropylene resin composition may be heat-bonded even at a lower temperature and may exhibit improved anti-blocking property and transparency.

The polypropylene resin composition is specifically examined for each component as follows.

a) propylene-ethylene- Butene Terpolymer

The polypropylene resin composition of the present invention comprises a polypropylene resin including a terpolymer of propylene, ethylene and butene. As the polypropylene-based resin includes a terpolymer of propylene, ethylene and butene, the heat-adhesive film formed of the resin composition may be heat-bonded at a low temperature and may exhibit excellent antiblocking properties.

The ethylene-propylene-butene terpolymer contains 0.5 to 3 wt% of ethylene derived units, 10 to 15 wt% butene derived units and the remaining amount of propylene derived units, and has a density of 0.89 to 0.91 g / cm 3. Phosphorus terpolymer.

The terpolymer may be a random copolymer in which 0.5 to 3 mol% of ethylene and 1.5 to 10 mol% butene are copolymerized with propylene, and more preferably 1 to 2 mol% of ethylene and 2 to propylene. 6 mol% of butenes can be copolymerized random copolymers. By using such a terpolymer as the polypropylene resin, it is possible to further improve the processability of the heat-adhesive film formed of the composition.

In addition, the polypropylene-based resin including the terpolymer may have a powder shape with an average particle diameter of 5 mm or less, preferably 2 mm or less, and may have a melt index of 1.0 to 10 g / 10 min. And the polypropylene resin may contain a soluble content of 2 to 8% by weight, preferably 4 to 6% by weight or less. As the polypropylene-based resin has such a property, it exhibits more improved thermal adhesive strength, and the temporal change of the wetness index can be reduced.

Ternary copolymers of propylene, ethylene and butene are included in the content range of 80 to 90% by weight relative to the total weight of the polypropylene resin composition. If the content of the terpolymer of propylene, ethylene and butene is less than 80% by weight, the mechanical properties of the polypropylene heat-adhesive film, for example, strength or impact strength, may be lowered. The thermal bonding temperature of the film is less likely to be low enough and the antiblocking property may be lowered.

b) propylene / Alphaolefin  Copolymer

The propylene / alphaolefin copolymer contains 0.5 to 10 wt% of units derived from alpha olefins, has a melt index of 1.0 to 10.0 g / 10 min (230 ° C.), a melting temperature of 120 to 135 ° C., and a density of Use 0.89-0.91 g / cm <2>.

In the present invention, the propylene / alpha olefin copolymer is prepared by injecting a propylene, alpha olefin and hydrogen as a molecular weight modifier in a series of reactors following the production of the propylene-ethylene-butene terpolymer and a reaction temperature of 50 to 100 ° C. And a polymerization reaction for about 30 minutes to 3 hours of polymerization time under a pressure of 5 to 50 bar to prepare an elastic copolymer. The content of the alpha olefin in the propylene / alpha olefin copolymer is preferably 0.5 to 10.0% by weight. If the alpha olefin content is less than 0.5% by weight, the compatibility with the propylene-ethylene-butene terpolymer is high, but the transparency is excellent, but there is a problem that the rigidity and impact strength, particularly low temperature impact strength is lowered, exceeding 10% by weight In this case, there is a problem that the impact strength is lowered.

The alpha olefins used in the present invention are ethylene or alpha olefins having 4 to 10 carbon atoms, and specific examples thereof include ethylene, butene, 1-pentene, 1-hexene, 1-octene, 1-dekene, 4-methyl-1-pentene, 3-methyl-1-pentene and the like may be used, and the alpha olefins may be used alone or in mixture of two or more thereof for copolymerization with propylene.

The propylene / alphaolefin copolymer can be prepared by slurry polymerization, bulk and gas phase polymerization, and gas phase polymerization is the most widely used.

The propylene / alphaolefin copolymer has a ratio (IV-b / IV-a) of the intrinsic viscosity number of the styrene-dissolved fraction of the propylene / alphaolefin copolymer to the intrinsic viscosity number of the propylene-ethylene-butene terpolymer The melt index is in the range of 0.5 to 150 g / 10 minutes to be 0.3 to 1. Transparency and impact resistance increase when using the thing of the said range.

In the present invention, a heterophasic propylene / alpha olefin copolymer including a propylene / alpha olefin copolymer having an alpha olefin content of 5 to 20 wt% may be used. The term "heterophasic propylene / alpha olefin copolymer" means a crystalline isotactic polypropylene phase in which an amorphous phase is dispersed. The use of heterophasic propylene / alpha olefin copolymers provides excellent transparency and flexibility. The melt index of the heterophasic propylene / alpha olefin copolymer is preferably 1 to 20 g / 10 minutes. If the melt index is 1 g / 10 min or less, the desired degree of transparency may not be obtained, and if the melt index is 20 g / 10 min or more, workability may be deteriorated.

The propylene / alpha olefin copolymer may be included in an amount of 1 to 10% by weight based on the total weight of the resin composition.

(c) ethylene Octene  Copolymer

The ethylene-octene copolymer contains 90 to 96 mol% of units derived from ethylene, and the rest includes octene. The ethylene-octene copolymer is selected from substantially linear polyethylene polymers and homogeneously branched linear polyethylenes. Ethylene-octene copolymers can be prepared using manufacturing processes known to those skilled in the art, such as gas phase, solution, or slurry polymer manufacturing processes.

The melt index (MI) of the ethylene-octene copolymer is 1 to 10 g / 10 minutes. The ethylene-octene copolymer preferably has a degree of crystallinity of 30 to 40% by weight. In the case of the ethylene 1-octene copolymer, the crystallinity corresponds to 14 to 25% by weight of polymerized units derived from 1-octene.

The ethylene-octene copolymer used in the present invention is a key component constituting the present invention, but is a high melt melt index and low molecular weight component, but it is an important component that improves processability without deteriorating melt tension and mechanical properties while maintaining low hardness. The ethylene-octene rubber resin preferably has an octene content of 20 to 30 wt% and a density of 0.900 to 0.910 g / ml. When the octene content is less than 20% by weight, the impact strength is lowered, and the copolymer having more than 30% by weight has a problem that the mold release property is lowered and the melt strength is lowered due to the low molecular weight. In addition, when the density is less than 0.900 g / ㎖ injection moldability is weak, the melt strength is weak when more than 0.910 g / ㎖ occurs.

In addition, the polypropylene resin composition of the present invention, various additives, for example, crystal nucleating agent, antioxidant, heat stabilizer, slip agent, antistatic agent, anti-blocking agent, filler, viscosity modifier, A coloring inhibitor and the like.

The resin composition of the present invention exhibits a melt index of 1 to 10 g / min, a melt temperature of 120 to 135 ° C, a melt strength of 0.1N to 0.2N, and a thermal bonding initiation temperature of 105 ° C or lower, and is soluble in xylene at room temperature. The content of phosphorus fraction is less than 5% by weight.

If the melt index (MI) of the resin composition of the present invention is less than 1.0 g / 10 min, the load is excessively applied to the processing equipment during film processing, the flow of the molten resin is uneven and the surface of the film is rough, and the melt index is 10.0 g / If it exceeds 10min, the melt strength is lowered, resulting in poor workability and film strength.

Melting temperature (T _m ) is in the range of 125 ~ 135 ℃, if the melting temperature is less than 125 ℃ there is a difficulty in the production process of polypropylene resin, if it exceeds 135 ℃ heat adhesiveness may be lowered.

Since the thermal bonding initiation temperature of the composition of the present invention is 105 ° C. or lower, which ensures rapid thermal bonding at low temperatures, the product to be sealed does not have to be exposed to high temperatures, and the low thermal bonding initiation temperature results in a cost reduction.

The composition of the present invention has a content of fraction soluble in xylene at room temperature of less than 5% by weight. Since the lower the content of the soluble fraction in the xylene means less sticky properties, the possibility of process failure during the processing and heat bonding process is extremely low.

In addition, the resin composition of the present invention has a melt strength in the range of 0.1N to 0.2N. From the viewpoint of film forming property, the higher the melt strength tends to improve the uniformity of the film thickness, and it is easy to form a dense surface. If the melt strength is less than 0.1 N, the uniformity of the film thickness is inferior, while if the melt strength is more than 0.2 N, the desired film thickness may not be maintained. Melt strength refers to the strength of the resin on the melt, and the melt-in (the extruded film width becomes narrower than the extruder die width) and weaving (phenomena of non-uniform width of the film) must be maintained at a melt strength of 0.1N to 0.2N or more. This improvement allows high speed machining, and if it exceeds 0.2 N, the workability may be degraded due to the decrease in flowability.

The ethylene-octene copolymer may be included in an amount of 1 to 10% by weight based on the total weight of the resin composition.

Although it is preferable to satisfy | fill the above characteristics with respect to a resin composition, it is also preferable that the whole film manufactured by the same composition satisfy | fills.

On the other hand, another aspect of the present invention relates to a polypropylene thermal adhesive film formed of the above-described polypropylene resin composition. Each component contained in the polypropylene heat-adhesive film corresponds to each component of the resin composition described above, and the same properties and kinds of materials as those components of these resin compositions can be used, and the content thereof is also resin. It may be equal to the content range of each component of the composition.

The above-mentioned polypropylene thermal adhesive film exhibits improved transparency and processability while also exhibiting excellent quality, for example, excellent printability, moldability, laminate properties and antiblocking properties, so that the thermal adhesive protective film for food or pharmaceutical packaging It can be preferably applied as.

In some food applications, the optical properties of the film, ie transparency, may be impaired during sterilization with steam, radiation or chemicals.

It can be advantageously used as a packaging material by satisfying low haze or high sharpness.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, this is presented as an example of the invention, whereby the scope of the invention is not limited.

Example

Example  One

0.1 parts by weight of primary antioxidant (Iganox-1010), secondary antioxidant (Igafos-168) as an additive to an ethylene-propylene-butene terpolymer having a melt index of 5 g / 10 min (230 ° C) and a melting temperature of 130 ° C. 0.1 parts by weight, neutralizing agent (Tinuvin770DF) was added in a content ratio of the following Table 1, and the propylene / alpha olefin having a melting index of 6 g / 10 min (190 ° C) and a melting temperature of 110 ° C, and 1-octene content was 20%. After mixing the ethylene-octene rubber having a density of 0.910 in the content ratio of Table 1 below, a pellet-like composition was obtained at 210 ° C using a twin screw extruder. The composition was extruded at a melting temperature of 240 ° C. using an extruder having a diameter of 40 mm and a T-die and quenched with cooling water having a surface temperature of 20 ° C. to form a film to obtain a roll-like film having a thickness of 30 μm and a width of 40 cm. . Various physical properties and performance of the obtained film were evaluated and shown in Table 2 below.

Example  2 ~ 6

Except for changing the ethylene octene copolymer to a different kind to carry out in the same manner as in Example 1 to obtain a polypropylene film, and to evaluate the overall physical properties and performance of the obtained film are shown in Table 2 together.

Comparative example  1-4

  Except that the composition of the polypropylene resin composition was changed as shown in Table 1, except that the same as in Example 1 to obtain a polypropylene film, the physical properties and performance of the obtained film was evaluated and shown in Table 2 below It was.

Test Example - Heat seal  Film performance evaluation

The physical properties of the polypropylene thermal adhesive films obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated by the following methods, and the results are shown in Table 2 below.

1) Melt index (MI): measured at a temperature of 230 ° C. and a load of 2.16 kg based on ASTM D1238DP.

2) Thermal Bond Initiation Temperature (SIT): Indicates the temperature at which the initial thermal bonding begins, and the condition is measured at the temperature at which the force of 100 g / 25 mm or more starts to act at 2 kg and 0.5 seconds. The lower the SIT value is, the better it is. However, if the SIT is 105 ° C. or less, “○” is indicated, and if it is more than 105 ° C., “X” is indicated.

3) Melt Strength (MS): Using a melt tension tester, the polypropylene to be measured is heated to 230 ° C., the molten polypropylene is discharged at an extrusion rate of 15 mm / min to form a strand, and the strand is 6.5 m / min. The tension at the time of taking in at the speed of was measured, and it measured by melt strength.

4) Haze: Transparency was measured according to ASTM D1003, and the lower the haze value, the better. The haze value was 2.0 or less, and " X "

Resin composition composition Performance evaluation division a b c-1 c-2 c-3 c-4 c-5 c-6 MI T _m SIT XS MS Haze Example 1 80 10 10 6 129 O 8 0.15 O Example 2 80 10 10 6 129 O 8 0.18 O Example 3 80 10 10 6 130 O 8 0.10 O Example 4 80 10 10 6 129 O 8 0.09 O Example 5 90 5 5 6 130 O 8 0.10 O Example 6 90 5 5 6 129 O 8 0.10 O Comparative Example 1 90 10 7 130 O 8 0.05 X Comparative Example 2 90 10 7 130 X 8 0.12 O Comparative Example 3 70 20 10 7 130 O 10 0.06 X Comparative Example 4 70 10 20 7 130 O 9 0.15 X Component (a): propylene-ethylene-butene-terpolymer, melting temperature 130 ° C., MI (230 ° C.) = 7.0 g / 10min
Component (b): propylene-alpha olefin copolymer, melting temperature 120 ° C.,
-Component (c-1): ethylene-octene rubber (1-octene content 20 wt%, density: 0.910)
-Component (c-2): ethylene-octene rubber (1-octene content 30 wt%, density: 0.900)
-Component (c-3): ethylene-octene rubber (1-octene content 25 wt%, density: 0.910)
-Component (c-4): ethylene-octene rubber (1-octene content 25 wt%, density: 0.900)
-Component (c-5): ethylene-octene rubber (1-octene content 10 wt%, density: 0.920)
-Component (c-6): ethylene-octene rubber (1-octene content 35 wt%, density: 0.890)

Referring to Table 1, the polypropylene thermal adhesive film of Examples 1 to 6 can be confirmed that the transparency and excellent workability, in contrast, the polypropylene thermal adhesive film of Comparative Examples 1 to 2 is not sufficient transparency and processability This is confirmed.

Although the above has been described in detail with reference to specific embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such modifications and claims are attached to the appended claims. It is to be understood as being included in the scope.

Claims (7)

Terpolymers of ethylene, propylene and butene;
Propylene-alphaolefin copolymers; And
An ethylene-octene rubber copolymer having a 1-octene content of 20 to 30% and a density of 0.900 to 0.910,
Where the melt index of 1-10 g / min, the melting temperature of 120-135 ° C., the melt strength of 0.1 N to 0.2 N, the thermal bonding initiation temperature of 105 ° C. or less and the content of fractions soluble in xylene at room temperature Polypropylene resin composition for heat-adhesive film, characterized in that less than 5% by weight.
The method of claim 1,
The ethylene-propylene-butene terpolymer includes 0.5 to 3 wt% of ethylene derived units, 10 to 15 wt% of butene derived units and the balance of propylene derived units, and a melt index of 1.0 to 10.0 g / It is 10 min (230 degreeC), The polypropylene resin composition for heat adhesive films.
The method of claim 1,
The propylene / alphaolefin copolymer has a unit derived from 0.5 to 10% by weight of alpha olefin, has a melt index of 1.0 to 10.0 g / 10 min (230 ° C.), and a density of 0.89 to 0.91 g / cm 3. Polypropylene resin composition for thermal adhesive films to be.
The method of claim 1,
The propylene / alpha olefin copolymer is a polypropylene resin composition for a heat adhesive film, characterized in that the heterophasic propylene / alpha olefin copolymer.
The method of claim 1, wherein the composition
(a) 80-90 weight percent of terpolymer of ethylene, propylene and butene;
(b) 1 to 10 weight percent of propylene-alphaolefin copolymer; And
(c) 1 to 10% by weight of an ethylene-octene rubber copolymer, wherein the polypropylene resin composition for a heat adhesive film.
The polypropylene heat-adhesive film formed from the polypropylene resin composition of any one of Claims 1-5.
7. The polypropylene thermal adhesive film of claim 6, wherein the film is applied as a thermal adhesive protective film to food or pharmaceutical packaging.