JPS5998147A - Polyolefin composition - Google Patents

Abstract

PURPOSE:A composition for molding a film, not causing blocking even by film molding through guenching, obtained by blending a polyolefin resin with finely divided silica, finely divided feldspar as fillers and a fatty carboxylic acid amide as lubricant in specific amounts, respectively. CONSTITUTION:A polyolefin resin (preferably linear low-density polyethylene) is blended with 0.05-1wt%, preferably 0.1-0.8wt% finely divided silica(preferably 3-8mu average particle diameter) and 0.05-1wt%, preferably 0.1-0.8wt% finely divided feldspar as fillers and 0.01-0.5wt%, preferably 0.05-0.2wt% fatty carboxylic acid amide(preferably unsaturated fatty acid amide such as oleic amide, etc.), to give the desired composition. EFFECT:A film having improved transparency is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to polyolefin compositions. Specifically, the present invention relates to a polyolefin composition suitable for use in forming a film.

Conventionally, polyolefin resins have been widely used for weight applications, and in particular, films have been widely used as packaging materials for everyday articles.

For example, T-die molding, inflation molding, etc. are often used to manufacture films using polyolefin resin + fat, and inflation molding, which extrudes in a cylindrical shape, is especially convenient when trying to obtain a bag-shaped molded product. It is often used for this reason.

When forming a film by inflation molding etc., in order to make the film transparent, the film extruded from the die is rapidly cooled using a coolant such as water.
Ru.

When the film is made transparent by this rapid cooling, the surface of the resulting film becomes smooth and stiff, and the density also decreases, making the film less stiff (reduced rigidity). As a result, even if a small amount of additives such as silica are added, the surface of the film cannot be made uneven; instead, the additives are incorporated into the film, causing the films to adhere to each other (blocking), or forming a cylindrical film. When flattened and pressed together, or when a single film is wound into a roll, the films stick together and cannot be peeled off. It was extremely inconvenient.

In order to eliminate the above-mentioned drawbacks of polyolefin resin, the inventors of the present invention have conducted autopsies on their own and have combined two glazes of specific erosive fillers with polyolefin resin, and also added a specific lubricant. The present inventors have discovered that by blending, a film with excellent transparency can be obtained that does not cause blocking even when film is formed by rapid cooling, and the present invention has been completed.

In other words, the gist of the present invention is to add fine powder silica to a polyolefin resin by θ, Oj~/in amount%, and fine powder feldspar to 0%.
．． 05-7% by weight, aliphatic carboxylic acid amide 0.0/
-0.3% by weight of the polyolefin composition.

The polyolefin resin used in the present invention includes high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, polybutene/, ethylene-vinyl acetate copolymer, etc. Suitable are medium-low density polyethylene and linear low-density polyethylene with a density θ, θl to θ, and a tag θft'/d, with linear low-density polyethylene being most suitable.

Linear low-density polyethylene is a copolymer of ethylene and other α-olefins, and is different from low-density polyethylene hh Jll produced by conventional high-pressure methods. Linear low-density polyethylene is a combination of ethylene and other α-olefins such as butene, hexene, octene, decene, etc., and is a Ziegler compound used in the production of high-bitterness polyethylene by a medium-low pressure method. Alternatively, it is produced using a Philippe type catalyst, in which conventional high-density polyethylene is made into a short or b-branched structure by combining, and the density is appropriately lowered by utilizing the original short chain branching. ,ri/~O9
tsy/ctA, and is a polyethylene with a structure that is more chain-like than conventional low-density polyethylene and more branched than high-density polyethylene.

The inorganic fillers that are blended together with such polyolefin resins are finely powdered silica and feldspar.

Powdered silica is a roughly spherical fine powder whose main component is purple silicon dioxide (5in2), and there are naturally occurring types and artificially synthesized types.

The silica used in the present invention may be natural silica or synthetic silica, and has an average particle size of /~10μ, preferably 3
~rμ is desirable. If the average particle size of silica is smaller than this, it will cause ridges and its dispersibility in the resin will be poor, and it will easily float in the air and cause stress, causing environmental hygiene problems.If it becomes larger than this, polyolefin After being mixed into a film and formed into a film, it gels and the film has a poor appearance, making it unsuitable for use.

The amount of silica in the polyolefin resin is θ, θ! ~/
In terms of weight, it is preferably O0/~θ, ♂% by weight; if it is a little more than this, the blocking prevention effect will not occur, that is, if it is made into a bag, the opening property will be poor, and if it is more than this, the film will be damaged. transparency is impaired.

Fine powder feldspar is composed of calcium (Ca)sodium (Na
), potassium (K), and other aluminosilicate as the main components, and is in the form of a roughly tabular fine powder, and is divided into sulfurs such as potassium feldspar, sourstone, scourite, plagioclase, etc. depending on the composition. However, it is usually a mixture of these. The feldspar used in the present invention may be in a mixed state as described above, and the proportion of each type of feldspar may be determined as desired, but the average particle size is 7-/θμ, preferably 3-1μ. Things are good.

To measure the average particle size of feldspar, as mentioned above, feldspar is tabular, so without considering the thickness, it is observed with a microscope, and the average value of the long side and short side is calculated. It was taken as the average particle size.

If the average grain size of feldspar is outside the above range, it is not preferable because it causes defects similar to those of silica.

The amount of feldspar contained in the polyolefin side fat is θ, O! ~/weight %, t weight or o, i~OI JL! However, if the amount is less than this, the anti-blocking effect will not occur, and if it is more than this, the transparency of the film will be impaired.

Aliphatic carboxylic acid amide is used as a specific lubricant used in conjunction with the above-mentioned combination of silica and feldspar. The aliphatic carboxylic acid amide has a melting point of 50 to 770°C, preferably 70 to θ. For example, oleic acid amide (melting point (MP) near! °C), erucic acid amide (MP: and 0
℃), ricinoleic acid amide (up: crc), erucic acid amide (MP: 7♂~♂/r), ), stearic acid amide (MP: /θθ℃), oxystearic acid amide (MP: 10sr: ), Methylolic acid amide (M
P: 102°C). Melting point is 770
If the temperature is higher than 0.degree. C., the speed at which the film bleeds onto the surface of the film will be slow when it is formed into a film, and it will contribute to the aperture of the film when it is not imparted with properties and is made narrower. The melting point! If the temperature is below θ°C, there may be problems such as excessive bleeding (1), for example, when light is applied to the surface of the take-up roll during molding and transferred to the film, giving a sticky feel that causes poor transparency.

Blend of aliphatic carboxylic acid amide - JU - usually 0.0/
~O, S weight%, preferably θ, θS ~ θ, 21%. If it is less than this, good lubricity can be imparted to the film. If it is more than this, it will cause excessive bleeding and the above-mentioned problem. Give rise to accompanying defects.

Forming a film using the composition of the present invention Pc'
Although the reason why the blocking of the M compound film can be effectively prevented has not been completely elucidated, it is thought to be due to the following reasons.

Silica and feldspar are each used as sacroiliac fillers. However, even if each of these substances is added to the resin, no anti-blocking effect can be obtained.

This is thought to be because silica has a roughly spherical shape as mentioned above, so the unevenness formed on the film surface is relatively uniform and smooth, and feldspar has a roughly spherical shape. This is thought to be because when the film is formed into a substantially flat plate-like shape, when the film is subjected to an operation such as melt-stretching, the film lines up substantially parallel to the film surface, and almost no irregularities are formed on the film surface. When silica and feldspar having an average particle size of However, since the feldspar is approximately parallel to the film surface and prevents it from collapsing, an extremely large number of irregularities due to silica and feldspar are formed on the film surface.
It is considered that blocking of the film can be effectively prevented.

As mentioned above, the composition of the present invention prevents blocking by forming a large number of fine irregularities on the surface of the film. θμ or less, preferably guO
It is very effective when used to produce films with a thickness of less than μ.

The present invention will be explained in more detail with reference to the following embodiments, but the present invention is not limited to the following embodiments unless the gist thereof is exceeded.

In the examples, regarding transparency, the haze value (9) was measured in accordance with J Engineering 5K-67/¥, and the haze value was Qj% or less [○], the haze value was G, ! ~t,
Those with a value of 717% were evaluated as [△], and those with a value of 6% or more were evaluated as [x].

Regarding the openability, the obtained film was made into a bag by heat-sealing, and then two overlapping test pieces of 2 cm x 2 cm were cut out from any arbitrary position of the bag. The test piece was heated to 20°C (relative humidity 60°C).
%) in a constant temperature room for 72 hours, and then peeled off both longitudinal ends of this test piece in a 1 m width to form an adhesive surface/OcnlX.
/ 0 > test piece. The ends of the four peeled films were each fixed to a chuck, and the chuck was moved in the direction of peeling the film at a moving speed of 30 mm 1 minute, and the maximum strength (2//θ0d) at which the film was pulled was Get this value! Of// 00 cr! The following [
○], jθ~/00 f/cJ [△],
/θ09//θOcr1 or more was evaluated as [x].

Laughter Example/～G, Comparative Examples 7-3 Linear low-density polyethylene (melt index (/0)
°C): / 1710 minutes, density 2θ, ri/za 9/crl
, co-association component nibten-/, co-1 synthesis component amount: /θ hill amount %
) with the additives shown in Table 7, and the T-die extrusion type (manufactured by Sumitomo Megumi + Yoshiki Kogyo 6, and the width of the extrusion die θρ).
mm, clearance, / with T-die installed)
Fat temperature 260℃, screw rotation i j Or
, p, m,, extrusion downward at an extrusion rate of 26 kfl/hr, and a water hole (
While quenching at a water temperature of -0°C, the film was taken at a speed of 3θin/min to obtain a film with a thickness of 3jμ.

The transparency and openness of the obtained film were evaluated and shown in Table 1.

In the Examples and Comparative Examples, "Silica A" is a silica (manufactured by Fuji Tevison ■, trade name: Thyroid #72) with an average particle diameter of 1 μm and a surface area of 220 m/yr, and [Silica BJ is , average particle size: 3.3μ, surface at
: 300n? / fr silica (manufactured by Fuji Davison ■, product name: Thyroid 4 (-za < t), "feldspar" refers to feldspar with an average particle size of 1.μ, surface area: 1.g
Manufactured by Shiraishi Calcium ■, product name: Minetsu 7),
Elk Biao Amide is manufactured by Nippon Kasei ■, part name: Diamid L2θO. (The same applies to the following Examples and Comparative Examples) Table 1 Note: All compounding amounts are weight %.

Example! ~2, Comparative Example Linear low density polyethylene (melt index (/) 0
°C): / yZio min, density g: 0.9.2/f
/cIIr, common synthetic component nibten-11 common synthetic component 2/θ friend%) is blended with the additives shown in Table 1,
Using an inflation molding method (made by Flako Co., Ltd.! A θβ extruder equipped with an inflation die having a block slit with a diameter/θ0 angle and a slit gap/mm), the side fat temperature was λθθ℃, and the screw rotation speed was 60 r, p. ,m,
, extrusion@2/kg/hr0, blow-up ratio/,
! A cooling ring was installed at a position directly below the die at a pressure of 20 degrees Celsius to allow cooling water (20 degrees Celsius) to flow down along the outside of the cylindrical film, allowing rapid cooling at 3θm/min.
A film having a thickness of Zθμ was obtained.

The transparency and openness of the obtained film were evaluated and shown in Table 2.

Table 2 Note 2 All compounding amounts are from N Company 9.

Example and ~/θ, Comparative Example-t~6 Instead of linear low density polyethylene, low density polyethylene (
Examples/~g except that Mitsubishi Chemical Corporation ■, Tsubachik-L-F /3/, Melt Index (/0℃): /, 31710 minutes, density 20, 2g) were used. A film was obtained in the same manner.

The transparency and openness of the obtained film were evaluated and shown in Table 3.

Table 3: / Nijil! ! l Otsu, 1 child 1 moro ≧ 7 more 14% 7
··be.

Claims (5)

[Claims] (1) Finely powdered silica is added to polyolefin resin at O8
OS~/wt%, fine powdered feldspar O1θ! A polyolefin composition containing ~/M amount % and aliphatic carboxylic acid amide in θ, θ/~0-jNfM-%. (2) The composition according to claim 1, which is a polyolefin resin or low density polyethylene. (3) In claim 1, which is polyolefin resin or linear low density polyethylene? The set il' is a parabola. (4) The composition according to any one of claims 1 to 3, wherein the silica has an average particle size of /~/θμ. (5) The composition according to any one of claims 7 to 7, wherein the feldspar has an average particle size of /~/θμ.