JPS6032836A - Antiblocking agent - Google Patents

Abstract

PURPOSE:To provide an antiblocking agent composed of a specific anhydrous amorphous aluminosilicate, and having excellent effect to prevent the blocking of a biaxially oriented film of polyolefin, polyester, etc. CONSTITUTION:The objective antiblocking agent is composed of amorphous aluminosilicate having a refractive index of 1.35-1.53 and an average particle diameter of 0.5-5mu, wherein the particles having diameter between 1/2 and 3/2 of the average particle diameter accounts for at least 50% of the whole particles. The agent is the one obtained by treating zeolite with an acid and heat, and remaining the particle state of the zeolite essentially unchanged. The zeolite is an A type zeolite having an SiO2/Al2O3 ratio (molar ratio) of about <=5, and the aqueous slurry of the zeolite is treated with an acid so as to attain a slurry pH of 5-7. The heat-treatment is carried out at 250-500 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-blocking agent made of anhydrous amorphous aluminide, and its purpose is to provide a well barrier that is excellent in blocking biaxially stretched films such as polyolefin and polyester. The aim is to provide the basics to demonstrate one's abilities.

Biaxially oriented films, such as polypropylene films, are the most commonly used packaging materials.

However, as is well known, this type of polyolefin film is sticky and tends to cause blocking properties, which not only impairs workability in film production and higher-order processing, but also hinders the use of the film. For example, when packaging or wrapping the bag, problems such as opening of the bag are likely to occur incorrectly. Therefore, this persimmon film is usually subjected to an anti-blocking treatment, and finely powdered silicic acid or kaolin flakes are typically known and used as anti-blocking agents.

On the other hand, excellent transparency is required as a trade characteristic of polyolefin films, but this transparency and blocking resistance are contradictory, so in order to improve the blocking resistance, Although it is possible to increase the amount added, the transparency decreases accordingly, so all conventional inorganic powders have drawbacks as additives for modifying suspensions that effectively satisfy both of these requirements. there were.

However, recently, it has been proposed to add zeolite powder to polypropylene in order to simultaneously satisfy both transparency and anti-blocking properties (Japanese Patent Publication No. 1973-
No. 16134).

This zeolite powder is made by mechanically pulverizing natural products or granulated synthetic products into extremely fine powders, and it has relative transparency and resistance compared to conventional clay or finely powdered silicic acid. Blocking properties have been improved.

However, with natural products, the transparency and anti-blocking properties of the film vary greatly and reproducibility is poor. Particularly in the case of mechanically pulverized particles, the major drawbacks are that the particle size distribution is necessarily wide, the particle surface is uneven, and there are complex fracture surfaces.

Therefore, in order to improve this, the present inventors investigated and discovered that special particles of synthetic zeolite have excellent blocking resistance of polyolefin films, and have already filed an application (Japanese Patent Application No. 57-300 issue).

However, as is well known, since zeolite emits crystallization water, under heating conditions during molding and film formation of synthetic resins, a foaming phenomenon accompanying rIW removal of crystallization water often occurs, resulting in defective products. This defect is caused by the fact that even when zeolite is heat-treated to remove the so-called zeolite water and become anhydrous activated zeolite, this water is easily re-adsorbed. It was impossible to eliminate the effects.

The inventors of the present invention have taken advantage of the excellent properties of zeolite and conducted extensive testing to eliminate the influence of zeolite water, and have developed a certain type of acid-treated zeolite. It was discovered that zeolite has a skeleton of zeolite as it is, and that the heat-treated product does not condense, and that it has an excellent anti-blocking effect on polyolefin films and polyester films due to its particle characteristics and refractive index characteristics. The present invention was completed.

That is, the present invention relates to an antiblocking agent characterized by comprising an acid and anhydrous amorphous aluminosilicate, which is a heat-treated product of zeolite, which is substantially in the form of zeolite particles.

Generally, zeolite has the general formula (1,0±02)M2O・
At203・xsio2-yH20 (M is Na
or an equivalent amount of a monovalent or polyvalent metal, where X is often between 15 and 20 and y is between θ and 10. A variety of silicates are known, including natural minerals and synthetic products (usually M is Na
).

Zeolites are also generally known to have unique adsorption and ion exchange properties based on their unique crystal structures, and a variety of uses have been developed that take advantage of these properties.

Therefore, the antiblocking agent according to the present invention is a zeolite that has been acid-treated and heat-treated to substantially have a skeleton in the basic particle form, and preferably has a constant particle size distribution and refractive index. It is an anhydrous amorphous aluminide having the following properties.

From this point of view, zeolites suitable as raw materials for producing the antiblocking agent of the present invention are those whose zeolite structure decomposes upon acid treatment, and in many cases, the zeolite structure is decomposed when treated with an acid, and in most cases, the 5i02/At203 (molar ratio) is approximately Zeolites with a molecular weight of 5 or less are preferred.

Such zeolites include, for example, A-type zeolite,
Examples include P-type zeolite, x-type zeolite, Y-type zeolite, sodalite or analcyme, and these are
One or more types of zeolite can be used, and of these, type A zeolite is particularly preferred from the viewpoint of industrial significance.

Therefore, the antiblocking agent according to the present invention is an anhydrous amorphous aluminosilicate obtained by subjecting the above-mentioned zeolite to acid and heat treatment. Acid treatment is particularly important in order to provide it as is.

That is, acid treatment involves adding an acid or an acidic substance to an aqueous slurry of bulk zeolite, so that even if the pH of the slurry is low, it is 4.5.
Preferably, it is adjusted to a weak acidity of 5 to 7.

If the pH value is less than 45, it is unsuitable because the state of the zeolite particles changes significantly or the entire particle dissolves or disappears, destroying the skeleton of the bulk zeolite.On the other hand, if the pH value is higher than 9, it is unsuitable. The degree of crystallization becomes insufficient.

Since the acid-treated raw zeolite contains the zeolite skeleton as it is, its anti-blocking ability strongly depends on the particle state of the zeolite.

In particular, the antiblocking agent according to the present invention has an average particle size in the range of 05 to 5 μm, and has an average particle size of 1.0 μm. The particle size part within the range of particle size from /2 to the particle size that is one factor of the average particle size is 5 of the whole.
It is preferable to have a particle size distribution of 0% or more, and the particle shape is preferably smooth with a substantially spherical or rounded particle surface, but these particle characteristics are According to microscopic observation, it can be said that the zeolite is substantially contained in the bulk zeolite.

The above-mentioned amorphous aluminosilicate is clearly distinguished from zeolite in its physical properties by X-ray diffraction, and for example, the cation exchange ability characteristic of zeolite has substantially disappeared. Also, although normal dried products retain moisture,
If the material is heated and dehydrated, condensation, such as in zeolite, will not substantially occur.

Therefore, the antiblocking agent according to the present invention is an anhydrous amorphous aluminosilicate obtained by substantially dehydrating the above-mentioned amorphous aluminosilicate at a temperature of at least 200°C or higher, preferably 250 to 500'C. . In addition,
In the present invention, amorphous refers to those in which no diffraction lines are observed in an X-ray diffraction diagram to those in which the height of the diffraction lines has decreased to below the Σ of zeolite, making it substantially amorphous. It refers to things that are included.

On the other hand, in addition to its performance, antiblocking agents are required to have a property that does not impair the transparency of the film when added to the film, and in general, transparency and blocking resistance are contradictory properties. However, since the anti-blocking agent according to the present invention has a refractive index adjusted to between 135 and 53, it is close to the refractive index of polyolefin and polyester films, so it is difficult to satisfy all the requirements at the same time. There will be no damage or loss.

This refractive index changes depending on the Ulj class of the bulk zeolite, its physical properties, acid, and heat treatment conditions, and is further influenced by cation substitution, so the bulk zeolite or amorphous aluminium non-refractive index is within the above refractive index range. It is preferable to adjust the cade.

Therefore, anhydrous amorphous aluminide has excellent performance as an anti-blocking agent by itself, but it may be modified to some extent as necessary to better suit the purpose of use. It may be.

As such a modified product, due to the slightly remaining cationic exchange ability, it is possible to slightly substitute other cationic compounds, such as Ca, Mg, Ba, Zn, or pb, with Na, or amorphous A coating treatment with silica or metal hydroxide may be applied.

For example, typical coating treatments include coatings with a continuous film of dense and fine amorphous silica, or fine white metal hydrated oxides such as aluminum, titanium, zirconium, antimony, etc. or modification of the particle surface with surfactants, dispersants, etc.

As described above, the antiblocking agent according to the present invention is an anhydrous amorphous aluminocide, and preferably has the above-mentioned particle characteristics and refractive index.On the other hand, the resin finosyme applied thereto is Although there are no particular limitations, it is particularly suitable for films made of polyolefin, polyester, and the like.

The polyolefin is not particularly limited as long as it has the ability to form a transparent and crystalline self-supporting film, but for example, a crystalline homopolymer of α-olefin having about 2 to 12 carbon atoms or Two or more types of crystalline copolymers, specifically polyethylene, polypropylene, poly-4-methylpentene-1, ethylene-propylene random or block copolymers, ethylene-propylene-
Examples include butene copolymers and ethylene-propylene-hexene copolymers. Among these, polypropylene, a copolymer of propylene with a majority weight of propylene and other α-olefins, or a copolymer of ethylene and other α-olefins are preferred, and in particular, polypropylene with an ethylene content of 0 to 10% is preferable.
6% by weight propylene polymer is good.

Further, these polyolefins are crystalline, and those having a tactical index (1■) of usually 40 or more, particularly 60 or more, particularly 90 or more are suitable. Furthermore,
It is used as long as it can be molded, but usually has a Nord flow rate (MFR) of 001 to 1009/1.
0 minutes, especially 01-507/10 minutes, especially 05-109
/10 minutes is preferably 96. In addition, polyesters include terephthalic acid or terephthalic acid dialkyl ester and general formula HO(CH2)nO
In the HC formula, n represents an integer from 1 to 10],
For example, ethylene glycol, trimethylene glycol,
It is a reaction product with alkylene glycol such as hexamethylene glycol and cyclohexane dimetatool.

In addition, other functional compounds that react with terephthalic acid or terephthalic acid dialkyl esters to form linear polyesters may be P-xylene glycols, hydroxynes, and cyclic glycols.

It may also be a polyester containing modifiers such as dibasic acids including isophthalic acid, sebacic acid, adipic acid, sulfonated derivatives, and the like. Other polymer films that can be used include polyamides such as nylon 66 and nylon 6, and halogen-containing polymers such as polyvinyl chloride.

The amount to be used as an anti-blocking agent in such a polymer varies depending on the type of polymer, the purpose of the film, the physical properties of the anti-blocking agent, etc., but in most cases it is 0.01 to 1.0% per 100M parts of the polymer. Parts by weight are appropriate, and 003 to 05 parts by weight is particularly preferred.

The reason for this is that if the amount is less than 0.001 parts by weight, the desired effect will not be sufficiently expressed due to the small amount added, and the accuracy of blending into the polymer and uniformly dispersing it will decrease; If the amount exceeds this amount, the transparency of the film will be impaired, the blocking resistance will not be improved considering the amount added, and the stretchability of the film will also be reduced.

It is of course possible to use other additives used in polymers, such as various antioxidants, stabilizers, processing aids, colorants, antistatic agents, but rather It is often observed that antiblocking agents enhance and enhance the performance of these additives, and more favorable effects may be observed.

In producing a film using the antiblocking agent according to the present invention, for example, the polyolefin composition is biaxially stretched by a conventional method to obtain a film with good workability, non-foaming transparency, and good blocking resistance. Films can be produced.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. The evaluation was conducted using the following test method.

Particle size distribution: Measured using a Coulter Counter (manufactured by Coulter Electronics) with an aperture tube diameter of 20 μm.

(Oa ion exchange capacity calcium chloride solution (300 m9/l as CaO) 1
Sample 12 (anhydride equivalent) was added to t and reacted by stirring at 25°C. After 15 minutes, the zeolite was quickly separated by filtration, the concentration of calcium (OaO) in the solution was analyzed, and the concentration of calcium (OaO) in the solution was analyzed. Calculate the amount of calcium and use this as the Ca ion exchange capacity.

[Composition analysis]

By atomic absorption spectrophotometry.

[Measurement of moisture]

Approximately 11 samples were weighed into a porcelain crucible and heated at 800'C for 1 hour to determine the weight loss.

[Refractive index]

It was measured by Larsen's oil immersion method using an Atsube refractometer.

[Measurement of equilibrium pH]

Sample powder 52 was added to 100 ml of ion-exchanged water with a pH of 7.0.
After stirring at 25°C for 30 minutes, the pH was measured using a pH meter (M-5, manufactured by Hitachi Horiba).

Example 1 Na-A zeolite 50 in a s o o cc beaker
Weigh out 200g of water and add 200g of water to make the zeolite concentration 20%.
250 g of slurry was prepared. Furthermore, the p of this slurry
H was 117. While stirring the slurry, 250 g of 4% sulfuric acid was gradually added thereto over about 5 minutes, and stirring was continued for 1 hour after the addition (during which time the pH of the slurry was always maintained at 4 or higher). Filtration, water washing, drying and pulverization were performed to obtain an acid-treated Na-, A-type zeolite. X-ray diffraction (X, R, D,
) Analysis revealed that no diffraction peaks were observed, indicating that it was an amorphous aluminonolicade.Next, this acid-treated product was dehydrated by heat treatment at a temperature of about 300°C for 211,000 hours to remove the necessary amount. Accordingly, it was lightly ground to obtain an antiblocking agent as shown in the electron micrograph of FIG.

FIG. 2 shows an electron micrograph of the bulk zeolite, and Table 1 shows the physical properties of the antiblocking agent as well as the physical properties of the bulk zeolite.

As is clear from these drawings and Table 1, the antiblocking agent according to the present invention is in the form of particles of raw zeolite;
That is, it can be seen that the skeleton is retained as is.

Example 2 Using the same Na-A zeolite as in Example 1, 4%
An antiblocking agent was obtained in exactly the same manner as in Example 1 except that JJ used 2% sulfuric acid instead of sulfuric acid. In X, R, D, and analysis, each diffraction peak of Na-A type zeolite has decreased in intensity to about 1/3 to 1/4, and it is clear that it contains a large amount of amorphous aluminosilicate. It is. The particle size distribution, average particle diameter, Ca ion exchange capacity, composition, etc. of this antiblocking agent are also shown in Table 1.

Example 3 An antiblocking agent was obtained in exactly the same manner as in Example 1 except that the same Na-A zeolite as in Example 1 was used and 10% phosphoric acid was used instead of 4% sulfuric acid. No diffraction peaks were observed in this product in the X, R, D, and quaternary analyses, and it is clear that it is an amorphous aluminonolicade. Particle size distribution, average particle size, and G of this antiblocking agent
a Ion exchange capacity, composition, etc. are also shown in Table 1.

Example 4 Using the same Na-A zeolite as in Example 1,
An antiblocking agent was obtained in exactly the same manner as in Example 1, except that % sulfuric acid was slowly added over about 30 minutes. In χ, R, D analysis, no diffraction peak of Na-A type zeolite was observed in this product, and it is clear that it is an amorphous aluminosilicate. The particle size distribution, average particle diameter, Ca ion exchange capacity, composition, etc. of this antiblocking agent are also shown in Table 1.

Example 5 Na-X zeolite (with an average particle size of 25μ and a particle size in the range of 1/2 to 12 of the average particle size accounts for 50% or more of the total particle size) was used in Example 1 A slurry was prepared in the same manner as above. Next, 5% phosphoric acid was gradually added, and the addition was terminated at pH 4.7. Next, filtration, washing with water, drying and pulverization were performed in a conventional manner to obtain an acid-treated product of Na-X zeolite.

When this acid-treated product was observed under an electron microscope, it was found that the particle state was exactly the same as that of the original zeolite, and even when the particle size was measured, it was almost the same as the original zeolite. No differences were observed, but
Line diffraction (X, R, D,) analysis showed that it was amorphous. Next, heat treatment was performed at 350° C. for 2 hours to obtain an antiblocking agent.

Each of the above anti-blocking agents, raw zeolite as a comparative example, hydrous amorphous aluminium non-liquefied without heat treatment in Example 1, and commercially available synthetic silica used as an anti-blocking agent (average particle size 0
A polypropylene composition was prepared in the following manner using 8μ) to obtain a biaxially oriented polypropylene film, and its quality was evaluated. The results were as shown in Table 2.

Production of film 100 parts by weight of a polypropylene resin with a melt flow rate of 1.9 P/10 minutes, 10 parts by weight of 2.6-di-butyl-p-cresol 0, and Irganox 10100. (12 parts by weight, 0.05 parts by weight of calcium stearate as a hydrochloric acid catching agent, and the anti-blocking agent according to the present invention in varying amounts of 001 parts by weight, 004 parts by weight, and 0.08 parts by weight), After mixing, the mixture was pelletized using an extruder.

Separately, materials such as A-type zeolite, synthetic silica, etc., as inorganic additives, and a material without the addition of inorganic additives (blank) were prepared in the same manner.

This pellet is made into a sheet-like film using an extruder,
The film was stretched 5 times in the longitudinal direction and 10 times in the transverse direction to finally obtain a stretched film with a thickness of 30 μm.

One side of the stretched film was subjected to corona discharge treatment.

The transparency, blocking properties, and heat resistance of these biaxially stretched films were measured.

The transparency of the film was measured by stacking four films in accordance with ASTM-D-]003.

The blocking property of the film can be determined by placing it between two glass plates so that the contact area of the two films is l Q tr2, applying several layers of 5 Q 9/6 u and heating at 40°C.
After being left in an atmosphere of
The maximum load was read and evaluated.

The foamability of the film was determined by mixing 1 part of the sample in 100 parts of resin (polyethylene (SMA-110)) at 170 parts.
The mixture was kneaded with a roll for 5 minutes at 170°C, then buried at 170°C for 4 minutes, and press-molded to a size of 1'Im# to obtain a test swash plate. The sample plate was sandwiched between glass plates like a sandwich layer, and left at 230° C. for 1 hour in a heating oven to observe the foaming state.

[Brief explanation of the drawing]

Figure 11 shows the electron microscope image of the budding inhibitor of the present invention, and Figure 2 shows the rIL of the raw Na-A type zeolite.
A microscopic photograph of the child is shown. Applicant Nihon Kagaku Kogyo Co., Ltd. Kazuo Wakasugi, Commissioner of the Japan Patent Office, December 2, 1981 Patent application for indication of the case No. 58-141872 2, Name of invention anti-blocking agent 3, Relationship with 41 amendments Patent applicant: 9-15-1 Kameido, Koto-ku, Tokyo Japan Chemical Industry Co., Ltd. Representative: Miki Tanahashi - 1-6 Kuchikibashi Muromachi, Chuo-ku, Tokyo Masaru Komasa Co., Ltd. Representative: Masaru Tomo 4, Representative: Sanshin Building 204, 1-4-1 Yurakucho, Chiyoda-ku, Tokyo
Room No. 501-2138 Toyota Naigai Patent Office (5941) Patent Attorney Yutaka 1) Yoshio 5. Date of amendment order November 29, 1980 (shipment date) 6. "Explanation" column 7, contents of amendment 1) "Electron micrograph" in lines 2-3 and 4 on page 24 of the specification is corrected to "electron micrograph showing particle structure."

Claims (2)

[Claims] (1) An antiblocking agent characterized by comprising anhydrous amorphous aluminosilicate, which is a heat-treated product and an acid of zeolite that is substantially in the form of zeolite particles. (2) Anhydrous amorphous aluminum non-licade has a refractive index of 135
-153 The antiblocking agent (3) according to claim 1, wherein the anhydrous amorphous aluminosilicate has an average particle size in the range of 05 to 5μ, and has an average particle size of 2 to 5μ. The antiblocking agent according to claim 1, characterized in that the particle size portion within the range of 100% of the average particle size is at least 50%.