JP2001288315A - Resin composition for forming film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for forming a film having excellent balance of physical properties such as mechanical strengths, heat resistance, blocking resistance, slipperiness, transparency, etc., and slight discoloration with time. SOLUTION: This resin composition is obtained by compounding 100 pts.wt. of a copolymer (I) of ethylene and a 3-18C α-olefin having 0.890-0.940 g/cm3 density and 0.3-20 g/10 minutes melt flow rate with 1-50 pts.wt. of a low-density polyethylene (II) produced by a high-pressure radical polymerization method, 0.01-0.1 pt.wt. of pentaerythritol tetrakis-[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] (IIIa), 0.02-0.3 pt.wt. of the total of at least two kinds of phosphorus- based heat stabilizer (IIIb), 0.05-1.0 pt.wt. of an antiblocking agent (IV) and 0.02-1.0 pt.wt. of a fatty acid amide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for forming a film, and more particularly to a resin composition which suppresses thermal deterioration during film formation and retains excellent mechanical strength, transparency, anti-blocking property and slipperiness. The present invention relates to a resin composition for forming a film which is less colored with time.

[0002]

2. Description of the Related Art Low-density polyethylene (hereinafter abbreviated as HP-LDPE) produced by a high-pressure radical polymerization method has been used for polyethylene films used for packaging and the like.
And ethylene-vinyl acetate copolymers and the like have been used. In recent years, linear low-density polyethylene (hereinafter referred to as L-polyethylene) obtained by an ionic polymerization method using a Ziegler catalyst or the like.
Since the development of L-LDPE,
Compared to HP-LDPE, they are superior in mechanical strength such as impact strength and low-temperature impact strength, heat resistance, stress cracking resistance, heat sealability, hot tack, etc., and are used in many fields. It has been used as a packaging material.

[0003] However, the film obtained by molding the above L-LDPE has a problem that it is inferior in the balance of physical properties such as transparency, anti-blocking property and slipperiness. In order to solve the above problems, for example, Japanese Patent Application Laid-Open Nos. 58-191733 and 59-9814
No. 7, JP-A-1-43546, etc.
Various studies have been made on additives such as a heat stabilizer, an anti-blocking agent, and a lubricant which are added at the time of film formation.

[0004] For example, tetrakis [methylene-3 (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate] methane is well known as the heat stabilizer. However, there was a problem that a film produced from the resin composition to which this was added had poor antiblocking properties.

Therefore, in the case where octadecyl-3- (4'-hydroxy-3,5'-di-tert-butylphenyl) propionate is used as the heat stabilizer, tetrakis [methylene-3 (3 ', 5 '-Di-t-butyl-4
-Hydroxyphenyl) propionate] was superior in anti-blocking property to that using methane. However, there is a problem in that the heat stabilizing effect is small and thermal deterioration is recognized during film formation.

[0006] The above-mentioned octadecyl-
If 3- (4'-hydroxy-3,5'-di-t-butylphenyl) propionate is used alone to obtain a sufficient heat stability effect, it must be added in a large amount. As a result, there is a problem that coloring may be recognized with time on the end face of the film after the film is formed.

As a method for increasing the transparency of a film, there is known a method of blending L-LDPE with HP-LDPE. However, although the film obtained by the above method has excellent transparency,
There is a problem that the anti-blocking property and the slip property are remarkably inferior. Further, for the purpose of solving the above problems, even if an anti-blocking agent such as silica and talc and a lubricant such as oleic acid amide which is an unsaturated fatty acid amide are added, the effects obtained by these additives are sufficient. However, it was difficult to sufficiently improve the anti-blocking property and the slip property.

In recent years, there has been an increasing demand for a film-forming resin composition that can be formed into a film having a good balance of various physical properties such as the above-mentioned transparency, anti-blocking properties, and slip properties.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a good balance of physical properties such as mechanical strength, heat resistance, anti-blocking property, slipperiness, and transparency, and has little coloring with time. An object of the present invention is to provide a resin composition for forming a film.

[0010]

Means for Solving the Problems According to the present invention, claim 1 is provided.
Has a density in the range of 0.890 to 0.940 g / cm ³ and a melt flow rate of 0.3 to 20 g / 1.
In 100 minutes by weight of a copolymer (I) of ethylene and an α-olefin having 3 to 18 carbon atoms in a range of 0 minute, low-density polyethylene (II) 1 to 1
50 parts by weight of pentaerythritol tetrakis- [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] (IIIa) in an amount of 0.01 to 0.1 part by weight and at least two kinds of phosphorus-based heat stabilizers (IIIb). 02 to 0.3 parts by weight and an anti-blocking agent (IV)
0.05 to 1.0 part by weight, and fatty acid amide (V) 0.0
2 to 1.0 part by weight is provided.

A second aspect of the present invention relates to the film-forming resin composition according to the first aspect, wherein the HP-LDPE (I
I) has a density in the range of 0.91 to 0.94 g / cm ³ and a melt flow rate of 0.1 to 50 g / 10
The present invention provides a resin composition for film molding having a range of minutes.
A third aspect of the present invention relates to the film-forming resin composition according to the first or second aspect, wherein the phosphorus-based heat stabilizer (IIIb) is used.
Are tris (2,4-di-t-butylphenyl) phosphite (IIIb1), tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite (IIIb2), and Bis [2,4-bis (1,1
-Dimethylethyl) -6-methyl-phenyl] ethyl phosphite (IIIb3).

According to a fourth aspect of the present invention, in the film-forming resin composition according to any one of the first to third aspects, the fatty acid amide (V) is a mixture of an unsaturated fatty acid amide and a saturated fatty acid amide. The blending weight ratio is 95: 5
The present invention provides a film-forming resin composition having a ratio of about 50:50.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The copolymer (I) used in the present invention (hereinafter referred to as (I)
Component)) converts ethylene and an α-olefin having 3 to 18 carbon atoms into a Ziegler catalyst, a Phillips catalyst,
It is obtained by ionic polymerization in the presence of a single-site catalyst or the like. The above copolymerization reaction is usually carried out at 30 to 3
The polymerization is carried out at a polymerization temperature of 00 ° C., at a normal pressure to a polymerization pressure of 3000 kgf / cm ² , in the presence of a solvent, in a gas-solid, liquid-solid or homogeneous liquid phase.

Examples of the α-olefin having 3 to 18 carbon atoms include propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, and decene-1.
And the like, and those having 4 to 10 carbon atoms are more preferably used. These α-olefins can be used alone or in combination of two or more.

The above component (I) has a density of 0.890 to 0.890.
0.940 g / cm ³ , preferably 0.910 to 0.9
35 g / cm ³ , more preferably 0.915 to 0.93
The range is 0 g / cm ³ . The above density is 0.890g
If it is less than / cm ^{3, the} film becomes sticky even if the additives described below are added, and the film has poor antiblocking properties. On the other hand, those exceeding 0.940 g / cm ³ have high rigidity, poor mechanical strength, and low transparency.

The melt flow rate (MFR) of the component (I) is 0.3 to 20 g / 10 min, preferably 0.4 to 10 g / 10 min, more preferably 0.5 to 10 g / 10 min.
５5 g / 10 min. The above MFR is 0.3 g
If it is less than / 10 min, the extrudability is inferior, and if it exceeds 20 g / 10 min, the melt viscosity is low and film formation is difficult.

The melt flow rate ratio (hereinafter abbreviated as MFRR) indicating the molecular weight distribution of the component (I) is 4
When it is 0 or less, more preferably 35 or less, a film having more excellent mechanical strength and transparency can be obtained. Here, the MFRR is JIS K7210.
M measured respectively according to conditions 7 and 4 of
Indicates the ratio of FR values and is determined by the following equation. MFRR
= The amount of extrusion per 10 minutes at a load of 21.6 kg / the amount of extrusion per 10 minutes at a load of 2.16 kg.

The HP-LDPE (II) used in the present invention
The compounding amount of the component (II) is required to be 1 to 50 parts by weight based on 100 parts by weight of the component (I). When the amount is less than 1 part by weight, transparency is poor, and when it exceeds 50 parts by weight, mechanical strength, heat sealing property, hot tack property and the like are poor.

The density of the component (II) is 0.89
It is preferably in the range of 0 to 0.940 g / cm ³ . If the density is less than 0.890 g / cm ³ ,
Tends to be poor in anti-blocking property, 0.940 g / c
which exceeds m ³ tends to be inferior in mechanical strength and transparency. The MFR of the component (II) is 0.1 to 50.
It is preferably in the range of g / 10 minutes. The above MFR
However, if less than 0.1 g / 10 minutes, extrudability, transparency,
Those having an anti-blocking property tend to be inferior, and those exceeding 50 g / 10 minutes tend to have inferior film processability.

The heat stabilizer (III) (hereinafter referred to as component (III)) used in the present invention is pentaerythritol tetrakis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate. ] (IIIa) (hereinafter,
(IIIa) component) and two or more phosphorus-based heat stabilizers (IIIb) (hereinafter, referred to as (IIIb) component) are used as a mixture.

The breakdown of the amount of the component (III) is (I)
The component (IIIa) is present in an amount of 0.01 to 100 parts by weight of the component.
0.1 parts by weight, preferably 0.01 to 0.07 parts by weight, and the component (IIIb) is selected in the range of 0.02 to 0.3 parts by weight, preferably 0.05 to 0.25. . (II
Ia) 0.01 parts by weight of the component, or (IIIb)
When the compounding amount of the component is less than 0.02 parts by weight, the heat resistance is inferior, the resin composition undergoes thermal deterioration during film formation, and the compounding amount of the component (IIIa) is 0.1 part by weight or (IIIb). If the amount of the component (3) exceeds 0.3 parts by weight, the anti-blocking property is inferior and coloring with time occurs.

The above component (IIIb) includes, for example, 3,5-di-t-butyl-4-hydroxybenzyl phosphite diethyl ester, bis (2,6-di-t-butyl-4-ethyl).
Methylphenoxy) diphosphospiroundecan, bis (stearyl) diphosphospiroundecan, cyclic netopentanetetraylbis (nonylphenylphosphite), bis (nonylphenylphenoxy) diphosphospiroundecan, 3,4,5 6-dibenzo-1,
2-oxaphosphane-2-oxide, tris (2,4
-Di-t-butylphenyl) phosphite, 2,4,6
-Tri-t-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite, 2,2'-
Methylenebis (4,6-di-t-butylphenyl) octyl phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methyl-phenyl] ethyl phosphite, bis (2,4-diphenyl -T-butylphenoxy) diphosphospiroundecan, trilauryltrithiophosphite, 1,1,3-tris (2-methyl-4-di-
Tridecyl phosphite 5-t-butylphenyl) butane, 2,2'-ethylidenebis (4,6-di-t-butylphenyl) fluorophosphite, 4,4'-isopropylidene diphenol alkyl (C12-C15 ) Phosphite, 4,4′-butylidenebis (3-methyl-
6-t-butylphenyl) -di-tridecyl phosphite, diphenyl isodecyl phosphite, diphenyl mono (tridecyl) phosphite, tris- (mono-, di-mixed nonylphenyl) phosphite, phenyl-bisphenol A pentaerythritol Diphosphite, di (laurylthio) pentaerythritol diphosphite, tetrakis (2,6-di-t-butyl-4-n-octadecyloxycarbonylethyl-phenyl) -4,
4'-biphenylene-diphosphonite, tetrakis [2,6-di-t-butyl-4- (2,4'-di-t
-Butylphenyloxycarbonyl) -phenyl]-
4,4'-biphenylene-diphosphonite), tricetyltrithiophosphite, a condensate of di-tert-butylphenyl-m-cresylphosphonite and biphenyl, tetrakis (2,4-di-t- Butylphenyl)
-4,4'-biphenylenediphosphonite, cyclic butylethylpropanediol-2,4,6-tri-butylphenylphosphite, tris- [2-
(2,4,8,10-tetrabutyl-5,7-dioxa-6-phospho-dibenzo- {a, c} cycloheptene-
6-yl-oxy) ethyl] amine, calcium bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate) calcium, 3,9-bis {2,4-bis (1-
Methyl-1-phenylethyl) phenoxy {-2,4,
A mixture of two or more selected from 8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane and the like is used.

Among the above compounds, tris (2,4-di-t-butylphenyl) phosphite (IIIb1) (hereinafter referred to as the component (IIIb1)), tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite (IIIb2) (hereinafter, referred to as (IIIb2) component) and bis [2,4-bis (1,1-dimethylethyl) -6-methyl-phenyl] ethylphosphonite It is particularly preferable to use a mixture of two kinds selected from phyto (IIIb3) (hereinafter, referred to as (IIIb3) component).

The anti-blocking agent (I) used in the present invention
The amount of V) (hereinafter referred to as component (IV)) is 0.05 to 1.0 part by weight, preferably 0.08 to 0.8 part by weight, per 100 parts by weight of component (I). is there. The above blending amount is
If the amount is less than 0.05 part by weight, the effect of improving the anti-blocking property cannot be obtained, and if it exceeds 1.0 part by weight, the transparency of the film decreases.

The component (IV) has an average particle size of about 0.3 to 8 μm and contains 5% by volume or less of particles having a particle diameter of 10 μm or more from the viewpoint of anti-blocking effect and transparency. preferable. Here, the particle size was measured using a Coulter counter after dispersing the component (IV) in an electrolytic solution for 2 minutes by ultrasonic treatment.

Specific examples of the component (IV) include amorphous aluminosilicate, kaolin, talc, zeolite, silica and the like. They may be natural or synthetic, and may be used alone or in combination of two or more.

Fatty acid amide (V) used in the present invention
(Hereinafter referred to as the component (V)) in the amount of the component (I) 10
It is 0.02 to 1.0 part by weight, preferably 0.03 to 0.5 part by weight, based on 0 part by weight. When the compounding amount is 0.
If the amount is less than 02 parts by weight, the slipping property and the anti-blocking property are remarkably reduced. If the amount exceeds 1.0 part by weight, not only slippage is caused but also printability is deteriorated.

As the component (V), a mixture of an unsaturated fatty acid amide and a saturated fatty acid amide is particularly preferably used. The compounding weight ratio of the unsaturated fatty acid amide to the saturated fatty acid amide is preferably from 95: 5 to 50:50, more preferably from 90:10 to 70:30. When the compounding weight ratio of the saturated fatty acid amide is less than 5, the effect of preventing blocking tends to decrease, and when it exceeds 50, the bleeding speed tends to be low and the slip property tends to be impaired. Specific examples of the component (V) include erucamide (melting point: 84 ° C.) as an unsaturated fatty acid amide.
And stearic acid amide (melting point: 103 ° C.) and behenic acid amide (melting point: 1) as saturated fatty acid amides.
10 ° C.).

The film-forming resin composition of the present invention may contain commonly used antistatic agents, weathering agents, UV agents, antifogging agents, etc. within a range that does not impair the object of the present invention. .

The film-forming resin composition of the present invention comprises the components (I), (II), (III), (IV),
It can be adjusted by melt-kneading the component (V) and the various additives used as desired according to a conventional method. As a specific method of the melt kneading, a method of mixing with a tumbler blender, a Henschel mixer, etc., a method of melt kneading and granulating with a single screw extruder, a multi-screw extruder, etc. after mixing, melting with a kneader, a Banbury mixer, etc. Examples of the method include kneading and granulating. Also, (I)
The component (III), the component (IV), and the component (V) can be obtained by melting and kneading and granulating the component by the above method and the component (II) by mixing with a tumbler blender or the like.

The resin composition for film formation obtained in this manner is formed into a film by a conventional air-cooled inflation molding method, an air-cooled two-stage cooling inflation molding method, a T-die film molding method, a water-cooled inflation molding method, or the like. can do.

The film thus obtained is excellent in the balance of physical properties such as mechanical strength, heat sealing property, hot tack property, heat resistance, anti-blocking property and slip property. It can be suitably used for various packaging films such as bags, sugar bags, oily material packaging bags, watery material packaging bags, agricultural materials, and the like. Further, since it has excellent transparency and little coloring with time, it can be used as a multilayer film by bonding it to a substrate such as nylon or polyester.

[0033]

The present invention will be described below more specifically with reference to examples. These examples show one embodiment of the present invention, and do not limit the present invention, and can be arbitrarily changed within the scope of the present invention.

Examples 1 to 8 and Comparative Examples 1 to 3 An air-cooled inflation molding machine for L-LDPE (extruder: screw diameter 55
mm, L / D = 28, spiral die 100 mm diameter,
(Lip opening 3m), blow ratio 2.2, processing temperature 1
The film was formed at 90 ° C. to a film thickness of 30 μm. Evaluation of various physical properties of the obtained film is performed according to the following method,
The results are shown in Table 4. The main materials are as follows. Component (I): linear low-density polyethylene (LLDPE) obtained with a Ziegler catalyst, density = 0.923 g / cm
³ , MFR = 0.9 dg / min. Component (II): High pressure radical method low density polyethylene (HP
-LDPE), density = 0.922 g / cm ³ , MFR =
1.5 dg / min. Component (IIIa): pentaerythritol tetrakis-
[3- (3,5-Di-t-butyl-4-hydroxyphenyl) propionate] (trade name: Irganox1010, manufactured by Ciba Specialty Chemicals). Component (IIIb1): Tris (2,4-di-t-butylphenyl) phosphite (trade name: Irgafos 168, manufactured by Ciba Specialty Chemicals). (IIIb2) component: tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite (Ciba Specialty Chemicals, trade name: P-EPQ). Component (IIIb3): bis [2,4-bis (1,1-dimethylethyl) -6-methyl-phenyl] ethyl phosphite (trade name: Irgafos 38, manufactured by Ciba Specialty Chemicals). Component (IIIc): octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) (Ciba.
Product name: Irgan, manufactured by Specialty Chemicals
ox1076).

(1) Transparency A haze value was measured in accordance with JIS K7105. (2) Degree of blocking The above film was adhered to a pressurized surface of 10 × 10 cm ² , 60
After promoting film adhesion for 5 hours at a temperature of 20 ° C. and a load of 20 kgf / 100 cm ² , the test piece was brought into contact with a surface of 10 × 10 cm ^2.
When the film was fixed to a peeling test jig and peeled off at a tensile speed of 500 mm / min by a tensile tester, the load required to completely peel off the film (gf / 100 cm ² )
Was measured, and the obtained measured value was indicated. The above measurement is a measure of the degree of anti-blocking properties of the film,
Smaller is more preferable.

(3) Slipperiness The outer surface / outer surface kinetic friction coefficient of the blown film was measured according to JIS K7215 and used as an index indicating the film's slipperiness. (4) Mechanical strength The mechanical strength of the film was measured according to JIS P8134. (5) Yellowness (YI) The yellowness (YI) when a sheet having a thickness of 2 mm was prepared and aged at 60 ° C. and 90% RH for 2 weeks was determined by AS.
It measured according to TMD7103. This value is a measure of the degree of coloration of the film over time.

(6) Thermal stability of resin composition Full-flight screw (L / D = 28, diameter 40 m)
Using m), each resin composition was extruded at an extrusion temperature of 210 ° C., the strand was cooled in water, and cut into pellets. This operation was repeated five times to obtain the MFR of each resin composition.
Was compared before and after the extrusion was repeated 5 times.
The greater the decrease in MFR after extrusion, the lower the thermal stability, and the more likely it is to cause coloring, burning, gel, etc. during film formation.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

[0041]

[Table 4]

(Summary of Examples 1 to 8 and Comparative Examples 1 to 3) From the results shown in Table 4, the resin compositions for film formation obtained in Examples 1 to 8 are excellent in heat stability, The film obtained by molding the composition was excellent in transparency with little coloring over time, mechanical strength, anti-blocking properties, and slipperiness. On the other hand, the resin composition for film molding obtained in Comparative Example 3 was inferior in thermal stability, and
The film obtained in 3 is transparent, anti-blocking,
It was inferior in slipperiness and markedly colored with time.

[0043]

As described above, in the resin composition for film forming of the present invention, thermal deterioration during film forming is suppressed, and transparency, mechanical strength, anti-blocking property, slip property, etc. are improved. A film having an excellent balance of physical properties can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08K 5/49 C08K 5/49 5/524 5/524 5/5393 5/5393 C08L 23/08 C08L 23 / 08 // (C08L 23/16 (C08L 23/16 23:06) 23:06) F term (reference) 4F071 AA14 AA14X AA15 AA15X AA18 AC11 AC12 AC15 AE05 AE11 AE22 AF13 AF30 AF45 AF58 AH04 AH05 BA01 BB09 BC01 4J051 BB032 BB032BB BB151 DJ008 DJ018 DJ038 DJ048 EJ066 EP019 EW067 EW127 FD066 FD067 FD208 GG01 GG02

Claims (4)

[Claims] (1) a density of 0.890 to 0.940 g / cm;
³ , and the melt flow rate is 0.3 to
Ethylene and carbon number 3-1 in the range of 20 g / 10 min.
8 to 100 parts by weight of a copolymer (I) with an α-olefin, 1 to 50 parts by weight of a low-density polyethylene (II) produced by a high-pressure radical polymerization method, and pentaerythritol tetrakis as a heat stabilizer (III). -[3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (IIIa) 0.01 to
0.1 part by weight, at least 0.02 to 0.3 parts by weight of at least two kinds of phosphorus heat stabilizers (IIIb), 0.05 to 1.0 part by weight of an anti-blocking agent (IV), A resin composition for forming a film, comprising 0.02 to 1.0 part by weight of a fatty acid amide (V). 2. The low-density polyethylene (II) has a density in the range of 0.91 to 0.94 g / cm ³ , and
The resin composition for forming a film according to claim 1, wherein the melt flow rate is in a range of 0.1 to 50 g / 10 minutes. 3. The phosphorous heat stabilizer (IIIb) comprises tris (2,4-di-t-butylphenyl) phosphite (IIIb1), tetrakis (2,4-di-t-butylphenyl) -4. , 4'-biphenylenediphosphonite (IIIb2), and bis [2,4-bis (1,1-dimethylethyl) -6-methyl-phenyl] ethylphosphite (IIIb3) The resin composition for forming a film according to claim 1, which is a mixture. 4. The fatty acid amide (V) is a mixture of an unsaturated fatty acid amide and a saturated fatty acid amide, and its blending ratio (unsaturated fatty acid amide: saturated fatty acid amide)
Is 95: 5 to 50:50, the resin composition for film molding according to any one of claims 1 to 3.