JP2003171565A - Resin composition containing inorganic fine particle and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition in which handling of a fine particle is easy and dispersibility of an inorganic fine particle is excellent. <P>SOLUTION: The resin composition comprises 80-99 parts by weight of a thermoplastic resin, i.e., a particle satisfying the following requirement: (A)-(C) and 1-20 parts by weight of an inorganic fine particle: requirement (A): that a weight average particle diameter is 500 μm or more, requirement (B): that a particle having a particle diameter of 200 μm or less is 1% by weight or more to less than 5% by weight and requirement (C): that a particle having a particle diameter of 500 μm or less is 15% by weight or more. In the method for manufacturing the resin composition, after the thermoplastic resin and the inorganic fine particle are mixed, the mixture is melted and kneaded. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition. More specifically, it relates to a resin composition which is easy to handle as a powder and has excellent dispersibility of inorganic fine particles.

[0002]

2. Description of the Related Art Conventionally, films and sheets obtained by using thermoplastic resins have been widely used as packaging materials for various products including foods. As a defect of the film itself obtained by using a thermoplastic resin, there is a deterioration in packaging suitability, and this defect is considered to be caused by so-called film blocking that the films adhere to each other when the films are stacked, In order to eliminate this drawback, it is widely practiced to incorporate inorganic fine particles into the film.

A widely used method for incorporating inorganic fine particles into a film is to mix a particulate thermoplastic resin with the inorganic fine particles, and then melt-knead the mixture to produce a pellet-shaped resin composition. This is a method of molding this to obtain a film.

For example, JP-A-58-225142 discloses a particle body having a particle size distribution represented by the Rosin-Rammler formula and having a particle size of 100 .mu.
The weight ratio of silicon dioxide to a fatty acid salt is 0.1% in a propylene polymer that does not contain 1% by weight or more of particles of .mu.
An olefin polymer composition is described which is blended in the range of 01 to 1 and is effective in improving the dispersibility of silicon dioxide.

Japanese Unexamined Patent Publication (Kokai) No. 8-81591 discloses an olefin polymer particle 100 having an average particle diameter of 500 to 1300 μm and a proportion of fine particles of 300 μm or less of 10% by weight or less.
In parts by weight, an inorganic fine powder having an average particle diameter of 1.0 to 4.0 μm and an apparent specific gravity of 0.20 to 0.60 g / cm 3 is 0.0
A polyolefin composition is described which comprises 5 to 0.60 parts by weight and is melt-kneaded.

The inorganic fine particles are mixed with the thermoplastic resin so that the concentration of the inorganic fine particles in the thermoplastic resin is high, and then the mixture is melt-kneaded to produce a masterbatch, which is prepared separately. Addition to thermoplastics is also widely practiced. For example, in JP-A-8-92424, an olefin polymer particle having an average particle diameter of 50 to 500 μ and a proportion of fine particles of 100 μ or less of 10 wt% or more is blended with an inorganic fine powder, and melt-kneaded to obtain. The concentration of the antiblocking agent is 3.0 to 25.0% by weight, the dispersibility of the antiblocking agent is good, and the film appearance, transparency, blocking resistance, and scratch resistance are good masters for polyolefin films. Batches are listed.

However, as described in JP-A-58-225142 or JP-A-8-81591, when olefin polymer particles are mixed with inorganic fine particles which are silicon dioxide (silica) powders, it is generally Since inorganic fine particles tend to aggregate during mixing, an aggregate of inorganic fine particles may be formed. Particularly, the above-mentioned JP-A-8-92.
As described in Japanese Patent No. 424, when a high-concentration masterbatch is produced, aggregates are likely to be formed. When the aggregates are mixed into the product film or sheet, the appearance of the film or sheet may be impaired and the product value may be reduced.

As methods for preventing the formation of aggregates, conventionally known methods include increasing the amount of fine particles in a thermoplastic resin, using a specific additive, and using inorganic fine particles having specific properties. ing. However, the method of increasing the amount of fine particles in the thermoplastic resin causes scattering,
The handling of fine particles becomes difficult and the risk of dust explosion increases. In addition, the use of the method using a specific additive or the method using inorganic fine particles having a specific property is limited. In such a situation, a method for producing a resin composition that can be applied to a wide range of uses, in which the concentration of the inorganic fine particles can be increased, the inorganic fine particles do not aggregate, and a resin composition having excellent dispersibility can be produced. A method was desired.

[0009]

An object of the present invention is to provide a resin composition which is easy to handle as a powder and has excellent dispersibility of inorganic fine particles.

[0010]

DISCLOSURE OF THE INVENTION In view of such circumstances, the present inventors have made earnest studies and, as a result, have determined that the weight average particle diameter is in a specific range and the proportion of particles having a particle diameter of a specific value or less is specified. , The particle size is in a specific range, the ratio of particles is in a specific range, the mixing ratio is a thermoplastic resin and a mixing ratio is a resin composition containing inorganic fine particles in a certain range. And a method for producing the resin composition, and the mixing amount is a mixture of the resin composition and the thermoplastic resin having a mixing range of a specific range, the film obtained by extrusion molding the above problems The inventors have found that they can be solved and completed the present invention.

That is, the present invention provides the following requirements (A)-
The present invention relates to a resin composition containing 80 to 99 parts by weight of a thermoplastic resin which is particles satisfying (C) and 1 to 20 parts by weight of inorganic fine particles, and a method for producing the resin composition. Requirement (A): The weight average particle diameter is 500 μm or more. Requirement (B): 1% by weight or more and less than 5% by weight of particles having a particle diameter of 200 μm or less. Requirement (C): 15 particles having a particle diameter of 500 μm or less
It is more than weight%. Hereinafter, the present invention will be described in detail.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin used in the present invention is a polymer obtained by polymerizing at least one monomer selected from ethylene, propylene, styrene and esters. A polymer obtained by polymerizing a monomer containing propylene as a main component, a polymer obtained by polymerizing a monomer containing propylene as a main component, and a polymer obtained by polymerizing a monomer containing styrene as a main component Examples thereof include a polymer and a polymer obtained by polymerizing a monomer having an ester as a main component, and a polymer obtained by polymerizing a monomer having a propylene as a main component is preferable. These polymers may be used alone or in combination of at least two kinds.

Polymers obtained by polymerizing a monomer containing ethylene as a main component include ethylene homopolymers, ethylene-propylene copolymers, ethylene and 4 to 1 carbon atoms.
Examples thereof include a copolymer of 2 α-olefins.

The propylene content of the ethylene-propylene copolymer may be 0.1 to 10% by weight based on the total weight of the ethylene-propylene copolymer.

Examples of the α-olefin having 4 to 12 carbon atoms include butene-1, hexene-1, octene-
1 and the like, and the α-olefin content is 0.1 to 50% by weight based on the total weight of the copolymer of ethylene and the α-olefin having 4 to 12 carbon atoms. Examples of the copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms include ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer and the like. To be

The polymer obtained by polymerizing a monomer containing ethylene as a main component is preferably ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1. It is a copolymer.

The method for producing a polymer obtained by polymerizing a monomer containing ethylene as a main component is not particularly limited, and a known polymerization method using a known polymerization catalyst can be mentioned. Known polymerization catalysts include, for example, Ziegler catalysts, metallocene catalysts and the like, and known polymerization methods include, for example, high pressure polymerization method, solution polymerization method, slurry polymerization method, gas phase polymerization method, etc. The polymerization method may be batchwise or continuous.

Examples of the polymer obtained by polymerizing a monomer containing propylene as a main component include a propylene homopolymer, a propylene-ethylene copolymer, and a copolymer of propylene and an α-olefin having 4 to 12 carbon atoms. Examples thereof include a ternary copolymer of propylene, ethylene, and an α-olefin having 4 to 12 carbon atoms.

The ethylene content in the propylene-ethylene copolymer may be 0.1 to 10% by weight based on the total weight of the propylene-ethylene copolymer.

In the copolymer of propylene and α-olefin having 4 to 12 carbon atoms, α having 4 to 12 carbon atoms
Examples of the olefin include α-olefin having 4 to 12 carbon atoms used in the polymer obtained by polymerizing the above-mentioned monomer containing ethylene as a main component, and the α-olefin content is propylene and carbon. Α with 4 to 12 atoms
0.1% by weight, based on the total weight of the olefin copolymer
˜30% by weight. Propylene and 4 carbon atoms
Examples of the α-olefin copolymer of
Examples thereof include a propylene-butene-1 copolymer and a propylene-hexene-1 copolymer.

Propylene, ethylene and 4 to 1 carbon atoms
The ethylene content of the α-olefin terpolymer of 2 is 0.1% by weight to the total weight of the terpolymer.
10% by weight can be used. 4 carbon atoms
Examples of the α-olefin having 12 to 12 include α-olefins having 4 to 12 carbon atoms which are used in a polymer obtained by polymerizing the above-mentioned monomer containing ethylene as a main component, and the α-olefin content is , 0.1 to 30% by weight based on the total weight of the terpolymer. Examples of the terpolymer of propylene, ethylene and α-olefin having 4 to 12 carbon atoms include propylene-ethylene-butene-1 copolymer and propylene-ethylene-hexene-1 copolymer. .

The polymer obtained by polymerizing a monomer containing propylene as a main component is preferably propylene homopolymer, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene. -1
It is a copolymer.

The method for producing a polymer obtained by polymerizing a monomer containing propylene as a main component is not particularly limited, and a known polymerization method using a known polymerization catalyst can be mentioned. Known polymerization catalysts include, for example, Ziegler catalysts, metallocene catalysts, etc., and known polymerization methods include, for example, solution polymerization method, slurry polymerization method, gas phase polymerization method, and the like. It may be a batch system or a continuous system.

The thermoplastic resin used in the present invention is particles, and the weight average particle diameter thereof is 500 μm or more, preferably 500 to 1000 μm. When the weight average particle diameter of the thermoplastic resin particles is less than 500 μm, it may be difficult to handle as a powder, such as a danger of dust explosion. The particle size of the thermoplastic resin can be measured using a laser diffraction type particle size distribution measuring device or the like.

In the thermoplastic resin used in the present invention, the amount of particles having a particle diameter of 200 μm or less is 1% by weight or more and less than 5% by weight based on the total weight of the thermoplastic resin. If the amount of particles having a particle size of 200 μm or less is less than 1% by weight, the dispersion of the inorganic fine particles may be insufficient. If the amount of particles is 5% by weight or more, there is a danger of dust explosion. It can be difficult.

In the thermoplastic resin which is a particle used in the present invention, the amount of particles having a particle diameter of 500 μm or less is 15% by weight or more based on the total weight of the thermoplastic resin,
It is preferably 15 to 40% by weight. Particles having a particle diameter of 500 μm or less as referred to herein have a particle diameter of 20 described above.
It also includes particles having a size of 0 μm or less. Particle size is 500μ
When the amount of particles of m or less is less than 15% by weight, the inorganic fine particles may be insufficiently dispersed.

The inorganic fine particles used in the present invention are not particularly limited, but those having an average particle diameter of 1 to 10 μm and an apparent specific gravity of 0.1 to 1 g / cc have the appearance and resistance of the film. It is preferably used in terms of blocking property and scratch resistance.

Specific examples of the inorganic fine particles used in the present invention include magnesium silicates such as silicon dioxide, aluminosilicate and talc, aluminum silicates such as kaolin, aluminum borate, calcium carbonate and the like. Among these, silicon dioxide is particularly preferably used because the effect of the present invention is great.

Regarding the mixing amount of the thermoplastic resin which is the particles and the inorganic fine particles used in the present invention, the mixing amount of the thermoplastic resin which is the particles is 80 to 99 parts by weight, and the mixing amount of the inorganic fine particles is 1 to 20 parts by weight. It is a department. Preferably, the mixing amount of the thermoplastic resin as particles is 90 to 98 parts by weight, and the mixing amount of the inorganic fine particles is 2 to 10 parts by weight.

When the mixing amount of the thermoplastic resin particles is less than 80 parts by weight (that is, when the mixing amount of the inorganic fine particles exceeds 20 parts by weight), the dispersibility of the inorganic fine particles may be insufficient. In addition, the mixing amount of the thermoplastic resin particles is 99
If the amount exceeds 100 parts by weight (that is, the amount of the inorganic fine particles is less than 1 part by weight), the blocking resistance is not improved unless added in a large amount when used in products such as films,
The value as a product may be low.

The mixing method used in the present invention is not particularly limited and may be a known mixing method, which is a method using a known mixing device. Examples of the apparatus used for mixing include a tumbler mixer, a super mixer, a Henschel mixer, a screw blender and a ribbon blender.

The resin composition of the present invention contains, if necessary, metallic soap, chlorine scavenger, antioxidant, ultraviolet absorber, light stabilizer, antistatic agent, lubricant, flame retardant, nucleating agent, pigment and the like. Additives may be added to the extent that the effects of the present invention can be maintained.

The method for producing the resin composition of the present invention is not particularly limited, but is preferably a method in which a thermoplastic resin and inorganic fine particles are mixed and then melt-kneaded. The melt-kneading method is not particularly limited as long as it is a method of melt-kneading at a temperature equal to or higher than the melting point of the thermoplastic resin. The device used for melt kneading is not particularly limited, and examples thereof include known melt kneading devices, and examples thereof include a uniaxial melt extruder, a biaxial or more multiaxial melt extruder, and a Banbury mixer. Among them, a multi-screw extruder having two or more screws is preferable.

The composition of the present invention can be prepared by extrusion molding, injection molding,
It can be suitably used for a wide range of applications such as foam molding and blow molding. Above all, it is preferably used for extrusion molding.

Mixtures of the resin composition of the present invention and other thermoplastic resins can also be suitably used in a wide variety of applications such as extrusion molding, injection molding, foam molding and blow molding. Particularly, it is suitably used for extrusion molding, and a film in which inorganic fine particles are well dispersed can be obtained.

[0036]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

(1) MFR: Measured according to JIS K7210 at a temperature of 230 ° C. and a load of 2.16 kgf. (2) Ethylene content: Polymer Handbook (1995
, Published by Kinokuniya Publishing Co., Ltd.), page 616, and measured by infrared spectroscopy. (3) Particle size and weight average particle size: SYMPATEC
Flow-through type laser diffraction particle size analyzer (HELO)
S & GRADIS) and an integral curve of the weight particle size distribution. (4) Appearance of film: The number of visually recognizable fish eyes per 200 cm ² of five stacked films was measured, and 40 or more were “defective”,
The thing of 40 or less was made into "good."

(Example) A thermoplastic resin having an MFR of 8
g / 10 minutes, weight average particle size is 770 μm, particle size is 2
The weight ratio of particles having a diameter of 00 μm or less is 1.3% by weight, and the weight ratio of particles having a particle diameter of 500 μm or less is 16.0.
The propylene-ethylene copolymer (ethylene content = 4% by weight) which is the weight% is used as inorganic fine particles in Sylysia 3
50 (manufactured by Fuji Silysia Chemical Ltd., average particle size by laser method 3.9 μm, apparent specific gravity 0.15 g / cc) was used. 98 parts by weight of the thermoplastic resin is preheated to 80 ° C. in a 20 L Henschel mixer (manufactured by Kawada Seisakusho), and 2 parts by weight of inorganic fine particles and the antioxidant Irganox 1010 (Ciba.
0.05 parts by weight of Specialty Chemicals Co., Ltd. and 0.10 parts by weight of Irgafos 168 (made by Ciba Specialty Chemicals Co., Ltd.) were added, and 1 at 535 rpm and 80 ° C.
Mix for minutes. Φ30mm biaxial kneader (T
EX30: manufactured by Nikko Seisakusho) was kneaded at 230 ° C. The handleability of the powder during manufacture was good. Into 5 parts by weight of the resin composition obtained by kneading as described above, a propylene-ethylene-butene-1 copolymer containing no inorganic fine particles (MFR =
(7 g / 10 min) 95 parts by weight was added, and a film having a thickness of 30 μm was formed at 250 ° C. using a T die. The appearance of the obtained film was good.

(Comparative Example 1) In the example, the thermoplastic resin has an MFR of 8 g / 10 minutes and a weight average particle diameter of 1320.
A propylene-ethylene copolymer in which the weight ratio of particles having a particle diameter of 200 μm or less is 0.2% by weight, and the weight ratio of particles having a particle diameter of 500 μm or less is 1.4% by weight (ethylene content = 4% by weight) was changed to the same as the example. The handleability of the powder at the time of production was good, but the appearance of the obtained film was poor because there were many aggregates of inorganic fine particles.

(Comparative Example 2) In the example, the thermoplastic resin was used, the MFR was 8 g / 10 min, and the weight average particle diameter was 600 μ.
m, the weight ratio of particles having a particle diameter of 200 μm or less is 0.8% by weight, and the weight ratio of particles having a particle diameter of 500 μm or less is 26.6% by weight (ethylene content = ethylene content). 4% by weight) was changed to the same as the example. The handleability of the powder at the time of production was good, but the appearance of the obtained film was poor because there were many aggregates of inorganic fine particles.

(Comparative Example 3) In the example, the thermoplastic resin was used in which the MFR was 8 g / 10 minutes and the weight average particle size was 410 μm.
m, the weight ratio of particles having a particle diameter of 200 μm or less is 7.1% by weight, and the weight ratio of particles having a particle diameter of 500 μm or less is 58.4% by weight (ethylene content = 4. The same procedure as in Example was performed except that the content was changed to (wt%). Although the appearance of the obtained film was good, it was difficult to handle the powder during production.

[0042]

[Table 1]

The resin compositions of Examples are excellent in both handling of powder during production and appearance of films obtained by using the resin compositions, whereas Comparative Examples 1 and 2
The appearance of the film obtained by using the resin composition of No. 1 is insufficient, and it can be seen that the resin composition of Comparative Example 3 is difficult to handle the powder at the time of production.

[0044]

As described above in detail, according to the present invention,
A resin composition which is easy to handle as a powder and has excellent dispersibility of inorganic fine particles can be obtained.

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Claims (4)

[Claims] 1. A thermoplastic resin which is particles satisfying the following requirements (A) to (C): 80 to 99 parts by weight and inorganic fine particles:
A resin composition comprising 20 parts by weight. Requirement (A): The weight average particle diameter is 500 μm or more. Requirement (B): 1% by weight or more and less than 5% by weight of particles having a particle diameter of 200 μm or less. Requirement (C): 15 particles having a particle diameter of 500 μm or less
It is more than weight%. 2. The resin composition according to claim 1, wherein the inorganic fine particles are silicon dioxide. 3. The resin composition according to claim 1, wherein the thermoplastic resin is a polymer obtained by polymerizing a monomer containing propylene as a main component. 4. After mixing the thermoplastic resin and the inorganic fine particles,
Melt kneading, The manufacturing method of the resin composition in any one of Claims 1-3 characterized by the above-mentioned.