KR102111340B1 - Tri-copolymerized polypropylene composition for thermal adhesive film excellent in low-temperature heat sealing composition and easy peeling property - Google Patents

Abstract

The present invention relates to a polypropylene-based resin composition, a mixture of propylene-alpha olefin copolymer and ethylene-alpha olefin copolymer in a propylene terpolymer in an appropriate ratio, a resin composition for a heat-adhesive film excellent in low-temperature heat sealing and easy peelability Gives

Description

Tri-copolymerized polypropylene composition for thermal adhesive film excellent in low-temperature heat sealing composition and easy peeling property}

The present invention relates to a method for producing a resin composition for a heat-adhesive film using a polypropylene (Polypropylene, PP) -based resin, and more particularly, to a resin composition for a heat-adhesive film excellent in low-temperature heat-sealing and easy peelability.

Thermal adhesive films using polypropylene resins are widely used for food and pharmaceutical packaging. Polypropylene (polypropylene) is a thermoplastic resin obtained by polymerizing propylene, and propylene obtained from petroleum, such as polyethylene, is polymerized with a Ziegler-Natta catalyst, and is made in the same way as low pressure polyethylene.

Polypropylene is a methyl group (CH3) attached to every other carbon in the chain of a polyethylene molecule, and has a short branched form. Polypropylene films are more transparent and slightly harder than polyethylene films.

Also, it is often used for molding, and bottle containers are made. The specific gravity is 0.92, which is the lightest among the existing plastics, and the melting temperature is high as 135 ~ 160 ℃, and its application range is wide. However, the drawbacks are that it is difficult to color and is slightly vulnerable to heat and light.

In general, propylene is formed with ethylene when decomposing naphtha in petrochemical plants. A Ziegler-Natta catalyst (typically, a complex salt composed of titanium trichloride and diethyl aluminum chloride) is made in a nucleic acid and propylene is easily synthesized by passing it at about 70 ° C and 5 atm. It has an isotactic structure, so the methyl groups are arranged in the same direction squarely as in the structural formula. The melting point is 165 ℃, and continuous use under load is possible at 110 ℃. The density is 0.9 to 0.91, and the crystallinity is large, but after molding, it decreases to 70% or less. The electrical properties are excellent because it consists only of carbon and hydrogen, and is comparable to polyethylene. Polypropylene is one of the four general-purpose resins, together with polyethylene, PVC, and polystyrene, and the proportion used in the thermoplastic resin is 24%. It also has the advantage of cost and environmental advantages.

In order to increase the production speed when packaging with a heat-adhesive film, the time required for heat-sealing must be reduced, so it must be adhered at high temperatures, or the temperature of the heat-adhesive of the resin must be lowered. Development) and weaving (a phenomenon in which the width of the film is not constant) occurs, making high-speed processing difficult. Therefore, low temperature heat sealability and easy peelability are required.

In order to solve this problem, conventionally, at low temperature, a solid solid (density is 0.91 to 0.94) has low crystallization to improve processability, flexibility, and transparency, and LDPE (Low Density Polyethylene) has been added to improve high-speed processability. There is a problem that the ease of writing is poor.

The problem to be solved by the present invention is propylene terpolymer (TerPP, Terpolymer) and propylene-alpha olefin copolymer, ethylene-alpha olefin copolymer is mixed at an appropriate ratio for a low-temperature heat sealable and easy-to-eat heat-adhesive film It is intended to provide a resin composition.

In order to solve the above problems, according to an aspect of the present invention, as a resin composition for a heat-adhesive film using a polypropylene-based resin, the resin composition is a propylene terpolymer (Terpolymer, TerPP) and two types of alpha-olefin copolymer A polypropylene-based resin composition comprising 80:20 to 90: 10% by weight is provided.

The polypropylene-based resin composition of the present invention is used for a heat-adhesive film that improves heat sealing and easy-filling properties by improving mixing accuracy and dispersibility with polypropylene by randomly applying two types of alpha olefin copolymer to a propylene terpolymer. Provided is a method of preparing a resin composition.

Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor appropriately uses the concept of terms to describe his or her invention in the best way. It should be interpreted as a meaning and a concept consistent with the technical idea of the present invention based on the principle that it can be defined as such. Therefore, the configuration described in the embodiments of the present specification is only an embodiment of the present invention and does not represent all of the technical spirit of the present invention, and various equivalents and modifications that can replace them at the time of this application It should be understood that there may be.

The present invention relates to a resin composition for a heat-adhesive film having excellent low-temperature heat-sealing properties and easy peelability, and mixing propylene-alpha olefin copolymer and ethylene-alpha olefin copolymer in an appropriate ratio in a propylene terpolymer to achieve low-temperature heat sealing and ease. Provided is a resin composition for a heat-adhesive film having excellent peelability.

One embodiment of the present invention, as a resin composition for a heat-adhesive film using a polypropylene-based resin, the resin composition is a propylene terpolymer (Terpolymer, TerPP) and two types of alpha olefin copolymer 80: 20 to 90: It provides a polypropylene-based resin composition consisting of 10% by weight.

In another embodiment of the present invention, the two types of alpha olefin copolymers are propylene alpha olefins, polypropylene-based one or more compositions selected from the group consisting of ethylene alpha olefins produced by copolymerizing alpha olefins Provided is a resin composition.

Another embodiment of the present invention provides a polypropylene-based resin composition, characterized in that the alpha-olefin of the two types of alpha-olefin copolymer is 5 to 10% by weight, respectively. When the content of the alpha olefin is less than 0.5% by weight, there is a problem that thermal adhesion and impact strength are deteriorated, and when it is 10% by weight or more, moldability becomes weak, which is not preferable.

In another embodiment of the present invention, the alpha olefin is 1-octene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-nonene, 1-decene, And it provides a polypropylene-based resin composition, characterized in that one composition selected from the group consisting of styrene.

In another embodiment of the present invention, the propylene terpolymer is a propylene: ethylene: 1-butene 85: 5:10 to 95: 0.5: 4.5 polypropylene-based resin composition, characterized in that consisting of weight percent Gives

In another embodiment of the present invention, the polypropylene-based resin composition provides a polypropylene-based resin composition characterized in that X / S (Xylene Solubility) is 0.1 to 8.0 wt%. The lower the X / S is, the less the low molecular weight component is, so the higher the thermal adhesion is.

In another embodiment of the present invention, the polypropylene-based resin composition provides a polypropylene-based resin composition, characterized in that the thermal fusion start temperature is 100 to 115 ° C. If the temperature of the start of heat fusion is less than 100 ° C, it is not desirable because of difficulties in the production process of polypropylene resin, and when it is above 115 ° C, the heat sealability is poor, and time and energy required for heat bonding must be entered. It is not desirable because it is not economically effective.

Hereinafter, the terpolymer used in the present invention will be described in detail.

The terpolymer (propylene terpolymer) of the present invention is i) the content of ethylene derived units is 0.3 to 5.0% by weight; Preferably in the range of 0.5% to 3.0% by weight;

ii) the content of 1-butene derived units ranges from 5 to 10% by weight;

iii) the content of ethylene derived units satisfies the following formula (I);

C2 <C6 * 0.16 (I);

Preferably formula (I) is C2 <C6 * 0.15; More preferably C2 <C6 * 0.14; Even more preferably C2 <C6 * 0.13;

In the formula, C2 is an ethylene derived unit and C6 is a 1-butene derived unit;

iv) melt mass flow rate measured according to ISO 1133, 230 ° C., 2.16 kg, MFR is 15 g / 10 min to 80 g / 10 min; Preferably from 20 g / 10 min to 50 g / 10 min; More preferably, it ranges from 25 g / 10 min to 45 g / 10 min.

The terpolymer contains only propylene, ethylene and 1-butene, and the sum of these three comonomer derived unit contents is 100% by weight.

To achieve the MFR of the terpolymer, it is also possible to pyrolyze the polymer with a lower MFR. To thermally decompose the polymer, known thermal decomposition agents such as peroxides can be used. By thermal decomposition, the MFR of the product can be finely adjusted.

The terpolymer has an isotactic type stereoregularity of the propylenic sequence, which is evident by the low value of the xylene extract, which is less than 15% by weight.

The terpolymer for a heat-adhesive film of the present invention can be prepared by polymerization in one or more polymerization steps. This polymerization can be carried out in the presence of a Ziegler-Natta catalyst. The essential component of the catalyst is a solid catalyst component comprising a titanium compound with at least one titanium-halogen bond and an electron-donor compound, both of which are supported on an active form of magnesium halide. Another essential component (cocatalyst) is an organoaluminum compound, such as an alkyl aluminum compound. External donors are optionally added.

Catalysts commonly used in the process of the present invention can produce polypropylene with xylene insoluble values of greater than 90%, preferably greater than 95% at ambient temperature.

The solid catalyst component used in the catalyst is a compound selected from the group consisting of ethers, ketones, lactones, compounds containing N, P and / or S atoms, and esters of monocarboxylic acids and dicarboxylic acids. -Included as donors (internal donors).

Particularly suitable electron-donor compounds are esters of phthalic acid and 1,3-diethers of the formula:

Wherein RI and RII are the same or different and are C1-C18 alkyl, C3-C18 cycloalkyl or C7-C18 aryl radicals; RIII and RIV are the same or different and are C1-C4 alkyl radicals; Or the carbon atom at position 2 is 5, 6 or 7 carbon atoms, or 5-n or 6-n 'carbon atoms, and each n nitrogen atom, n selected from the group consisting of N, O, S and Si 1,3-diether belonging to a cyclic or polycyclic structure composed of 'heteroatoms, wherein n is 1 or 2, n' is 1, 2 or 3, and the structure is 2 or 3 unsaturated Containing (cyclopolyonic structures), optionally condensed with other cyclic structures, or linear or branched alkyl radicals; The above-mentioned substituents which may be substituted with one or more substituents selected from the group consisting of cycloalkyl, aryl, aralkyl, alkali radicals and halogens, or condensed with other cyclic structures and also bonded to condensed cyclic structures. Substituted with one or more of; One or more of the above-mentioned alkyl, cycloalkyl, aryl, aralkyl or alkaryl radicals and condensed cyclic structures may optionally contain one or more heteroatom (s) as substituents for carbon atoms, hydrogen atoms or both atoms. Contains.

Representative examples of the diether include 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane and 2-isopropyl-2- Cyclopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isoamyl-1,3-dimethoxypropane, 9,9-bis (methoxymethyl) fluorene.

Other suitable electron-donor compounds are phthalic acid esters, such as diisobutyl, dioctyl, diphenyl and benzylbutyl phthalate.

It is also possible to use mixtures of at least two electron donor compounds, one of which is present in an amount of from 30 mol% to 90 mol% relative to the total amount of the donor and is selected from succinate, the other is 1, 3-diether.

Hereinafter, specific examples are provided to help understanding of the present invention. However, the following examples are provided only to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

The physical properties of the resin composition prepared in this example were measured by the following method.

<Method for measuring physical properties>

1) Melt Flow Index (MI): Based on ASTM D1238DP, the weight of the resin flowed for 10 minutes was measured using a temperature of 230 ° C. and a load of 2.16 kg.

2) Melting point (Tm): The melting point was measured through a change in heat capacity according to a thermal change (10 ° C / min rise) of a sample through a differential scanning calorimeter (DSC).

3) Thermal adhesion initiation temperature (SIT): indicates the temperature at which the initial thermal adhesion begins, and the condition is measured at a 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, the better it is. If the SIT is 110 ° C or lower, it is indicated as "○", and if it is 110 ° C or higher, it is represented as "X".

4) Xylene Solubility (X / S): refers to the value in terms of wt% of the component dissolved in the xylene in which the polymer is boiled and the isotactic component precipitated and only the atactic component remained.

5) Transparency (Haze): Transparency was measured in accordance with ASTM D1003, and the lower the haze value, the better the haze value.

<Example 1>

 To prepare a polyolefin-based resin composition, a resin composition was prepared by adding a propylene-alphaolefin copolymer and an ethylene-alphaolefin copolymer to a terpolymer composed of propylene, ethylene, and 1-butene. The terpolymer was 80% by weight, the propylene-alpha olefin copolymer was 10% by weight (melting temperature 120 ° C), and the ethylene-alpha olefin copolymer was copolymerized at 10% by weight (1-octene 20 content%, density 0.910). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 129 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more.

<Example 2>

Performed in the same manner as in Example 1, the terpolymer 80% by weight, propylene-alpha olefin copolymer 10% by weight (melting temperature 120 ℃), ethylene-alpha olefin copolymer 10% by weight (1-octene 30 content% , Density 0.900). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 129 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more.

<Example 3>

Performed in the same manner as in Example 1, the terpolymer 80% by weight, propylene-alpha olefin copolymer 10% by weight (melting temperature 120 ℃), ethylene-alpha olefin copolymer 10% by weight (1-octene 10 content% , Density 0.920). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 129 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more.

<Example 4>

Performed in the same manner as in Example 1, the terpolymer 80% by weight, propylene-alpha olefin copolymer 10% by weight (melting temperature 120 ℃), ethylene-alpha olefin copolymer 10% by weight (1-octene 35 content% , Density 0.890). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 129 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more.

<Example 5>

Performed in the same manner as in Example 1, the terpolymer 90% by weight, the propylene-alpha olefin copolymer 5% by weight (melting temperature 120 ℃), ethylene-alpha olefin copolymer 5% by weight (1-octene 20 content% , Density 0.910). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 130 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more were found.

<Example 6>

Performed in the same manner as in Example 1, the terpolymer 90% by weight, the propylene-alpha olefin copolymer 5% by weight (melting temperature 120 ℃), ethylene-alpha olefin copolymer 5% by weight (1-octene 30 content% , Density 0.900). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 6g / min, Tm 129 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or more.

<Comparative Example 1>

It was carried out in the same manner as in Example 1, terpolymer was 90% by weight, propylene-alpha olefin copolymer was copolymerized to 10% by weight (melting temperature 120 ℃). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 7g / min, Tm 130 ° C, SIT 110 ° C or less, X / S 8 wt%, easy-filling 'not suitable', and transparency 2.0 or less.

<Comparative Example 2>

It was carried out in the same manner as in Example 1, the terpolymer was 90% by weight, the ethylene-alpha olefin copolymer was copolymerized to 10% by weight (1-octene 20 content%, density 0.910). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 7g / min, Tm 130 ° C, SIT 110 ° C or higher, X / S 8 wt%, easy-filling 'fit', and transparency 2.0 or higher.

<Comparative Example 3>

The same procedure as in Example 1 was carried out, but the terpolymer was 70% by weight, the propylene-alpha olefin copolymer was 20% by weight (melting temperature 120 ° C), and the ethylene-alpha olefin copolymer was 10% by weight (1-octene 35 content %, Density 0.890). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 7g / min, Tm 130 ° C, SIT 110 ° C or less, X / S 10 wt%, easy-filling 'not suitable', and transparency of 2.0 or less.

<Comparative Example 4>

The same procedure as in Example 1 was carried out, but the terpolymer was 70% by weight, the propylene-alpha olefin copolymer was 10% by weight (melting temperature 120 ° C), and the ethylene-alpha olefin copolymer was 20% by weight (1-octene 10 content %, Density 0.920). As a result of evaluating the physical properties of such a polyolefin-based resin composition, MI 7g / min, Tm 130 ° C, SIT 110 ° C or less, X / S 9 wt%, easy-filling 'not suitable', and transparency of 2.0 or less.

The experimental results through the examples and comparative examples are summarized in Table 1 below.

Resin composition composition Performance evaluation (○ good, × bad) Category (wt%) a b c-1 c-2 c-3 c-4 MI T _m SIT X / S Lee Ji-pil Haze Example 1 80 10 10 6 129 O 8 O O Example 2 80 10 10 6 129 O 8 O O Example 3 80 10 10 6 130 O 8 O O Example 4 80 10 10 6 129 O 8 O O Example 5 90 5 5 6 130 O 8 O O Example 6 90 5 5 6 129 O 8 O O Comparative Example 1 90 10 7 130 O 8 X X Comparative Example 2 90 10 7 130 X 8 O O Comparative Example 3 70 20 10 7 130 O 10 X X Comparative Example 4 70 10 20 7 130 O 9 X X -Component (a): Propylene-ethylene-butene-ternary copolymer, 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-alpha olefin (1-octene content 20 wt%, density: 0.910)
-Component (c-2): Ethylene-alpha olefin (1-octene content 30 wt%, density: 0.900)
-Component (c-3): Ethylene-alpha olefin (1-octene content 10 wt%, density: 0.920)
-Component (c-4): Ethylene-alpha olefin (1-octene content 35 wt%, density: 0.890)

Summarizing the above results, in the case of Examples 1 to 6, the melt index and melting point are suitable, the thermal adhesion start temperature is 110 ° C. or less, xylene solubility (X / S) 8 wt% or less, and transparency is 2.0 or more. It showed excellent results.

Considering on the basis of these results, the terpolymer (propylene, ethylene, 1-butene terpolymer) as in the present invention is propylene-alpha olefin copolymer 5 to 10% by weight, ethylene-alpha within the range of 80 to 90% by weight Comparative examples not added in the case of Examples in which 3 to 10% by weight of the olefin copolymer is added to the composition, but the 1-octene content of the ethylene-alpha olefin copolymer satisfies 10 to 35 wt% and density 0.890 to 0.920. It was confirmed that MI, SIT, X / S, haze (transparency) and easy peeling properties were suitable.

Claims (7)

As a resin composition for a heat-adhesive film using a polypropylene-based resin,
The resin composition is 80 to 90% by weight of a propylene-ethylene-1-butene terpolymer; 5-10% by weight of propylene-alpha olefin copolymer; And 5 to 10% by weight of ethylene-alpha olefin copolymer,
The resin composition has a xylene solubility (X / S) of 0.1 to 8.0 wt%,
The 1-octene content of the ethylene-alpha olefin copolymer is 10 to 35% by weight, the density is 0.890 ~ 0.920g / m ³ polypropylene-based resin composition.
delete delete According to claim 1,
The alpha olefin is one selected from the group consisting of 1-octene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-nonene, 1-decene, and styrene. Polypropylene-based resin composition, characterized in that the composition.
According to claim 1,
The propylene-ethylene-1-butene terpolymer is a polypropylene-based resin composition, characterized in that propylene: ethylene: 1-butene is composed of 85% by weight in the range of 85: 5: 10 to 95: 0.5: 4.5.
delete According to claim 1,
The polypropylene-based resin composition is a polypropylene-based resin composition, characterized in that the thermal fusion start temperature is 100 to 115 ℃.