JPS60238339A - Tear sheet - Google Patents

Abstract

PURPOSE:A tear sheet is obtained by adding a specific amount of an inorganic filler to an olefinic polymer so that the resultant composition has a specific friction coefficient, thus showing high heat resistance, water resistance and enabling repeated use, because it is washable and sanitary and has dusting effect. CONSTITUTION:An olefinic polymer, preferably a propylene polymer with MFI of 0.1-10g/10min, is combined with 5-40wt% of an inorganic filler, preferably a talc of 2-10mu particle sizes, made into sheets. Then, the sheets are embossed on its at least one surface partially or wholly, sand-blasted to make the surfaces coarse, resulting in differing the friction coefficient of one surface from the other. The thickness of the tear sheets are selected in the range from 0.3-15mm., preferably from 0.5-10mm..

Description

[Detailed description of the invention] B. Industrial application field The present invention relates to a tear sheet for conveying containers.

More specifically, olefin polymer and inorganic filler 5 to 4
0% by weight (based on the olefin polymer), and the sheet-like material has a friction coefficient on one side larger than that on the other side and a thickness of 0.3 to 151III. The tear sheet is heat resistant, highly water resistant, washable and hygienic, and not only can withstand repeated use.
The present invention relates to a tear sheet that has a dustproof effect on unfilled containers, facilitates stacking of containers, and improves work efficiency.

In recent years, metal containers used for soft drinks, beer, cans of edible oil, etc., glass containers used for pharmaceuticals, industrial chemicals, liquid seasonings, liquid detergents, seasonings, ice cream, etc. Large quantities of various containers are used in many fields, such as plastic containers used in the field of transportation, and most of the cargo handling operations such as packing and transporting these containers have been automated.

One aspect of the above-mentioned packaging and transportation is unit loading. In this method, when handling and transporting containers, etc., they are grouped into an appropriate number or weight and made into one unit.
This is a method of handling cargo using equipment in an integrated manner without having to dismantle it midway. That is, after a certain number of containers are stacked in multiple rows and multiple stages on a pallet to form a unit, the units are packed by shrink wrapping or banding, and then used for cargo handling operations. When containers are stacked in multiple tiers to form a unit, a sheet, ie, a tear sheet, is inserted into each tier for the purpose of stabilizing the containers, preventing cargo from collapsing, and preventing dust.

Conventionally, paper boards have been used as tear sheets, but not only are they impossible to clean and cannot be used repeatedly, but paper fiber waste inevitably gets mixed in when transporting unfilled containers, which can cause problems later. There are concerns that it may cause In addition, because the material is paper, it is prone to fuzzing, damage, and contamination.
It is unhygienic and its use is restricted in fields where dust is averse, such as food and medicine.

On the other hand, as a plastic tear sheet, a sheet made of a random copolymer of 2 to 10% ethylene and 90 to 98% propylene has been proposed (International Publication No. W
O32101861). However, when this tear sheet is subjected to high temperature sterilization in a unit load state for repeated use after cleaning, the tear sheet not only bends and deforms, but also requires banding and heating the unit load. There are problems such as bending of edges and corners due to shrink wrapping.

Problems to be Solved by the Invention The present invention solves the problems in the prior art as described above. That is, it is an attempt to solve problems such as lack of heat resistance and water resistance, impossibility of high-temperature sterilization and washing, easy breakage and contamination, and easy generation of fiber waste.

Therefore, the present invention has high heat resistance and water resistance.

It is washable and hygienic, and not only can withstand repeated use, but it also has a dust-proofing effect on unfilled containers.It also makes it easy to stack containers, improving work efficiency, and is suitable for shrink-wrapping or stacking. To provide a tear sheet that does not bend or deform when being loaded.

20 Means for Solving the Problems Tier C 1 of the present invention consists of a composition mainly containing a blend of an olefin polymer and an inorganic filler of 5 to 40% by weight (based on the olefin polymer). , and the friction coefficient of one side is larger than the friction coefficient of the other side, and the thickness is 0.3 to 1
It consists of a 5am sheet-like material.

Examples of the olefin polymers include low, medium and high enrichment polyethylene, polypropylene, polybutene-1, poly-
Examples include homopolymers such as 4-methylpentene-1, copolymers with other α-olefins containing ethylene or propylene as the main component, and mixtures thereof.
From the viewpoint of heat resistance, a crystalline polymer consisting of an olefin having 3 or more carbon atoms is preferred. Particularly preferred are propylene homopolymers and block copolymers.

The MFI (melt flow index) of the propylene polymer described in L is preferably in the range of 0.1 to Log/10 minutes.

If the MFI is less than 0.1 g/10 minutes, the flow of the molten resin will be poor and the screw power of the extruder will become too high, making it difficult to produce a good sheet. On the other hand, MFI is 10g/1
If the time exceeds 0 minutes, the web of molten resin will droop;
Good molding is not possible. Furthermore, there is a concern that the strength and other physical properties of the sheet may deteriorate.

If necessary, the above polymers may be added to τ synthetic rubber such as styrene-butadiene copolymer rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, butyl rubber, chloroprene rubber, or natural rubber. It is also possible to mix elastomers such as.

The inorganic filler used in the present invention is powder-like, flat-like, scale-like, needle-like, spherical or hollow, fibrous,
It has a shape such as fibrous fabric, and specific examples include calcium carbonate, magnesium carbonate, calcium sulfate, calcium silicate, barium sulfate, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium sulfite, mica, Clay, diatomaceous earth, talc, zeolite, zinc oxide, titanium oxide, molybdenum sulfide, quartz powder, bentonite, alumina, silica sand, iron oxide, metal powder, antimony trioxide, graphite, silicon carbide, silicon nitride, silica, boron nitride, nitride Powder-like fillers such as aluminum, white carbon, carbon black, glass peas, glass powder, and silica stone; flat or scaly fillers such as mica, glass plates, sericite, pyrophyllite, aluminum flakes and other metal foils, and graphite. Hollow fillers such as wood, shirasu balloons, metal balloons, glass balloons, and pumice, fibrous materials such as glass fibers, whiskers, metal fibers, silicon carbide fibers, carbon fibers, graphite fibers, asbestos, and mineral fibers such as wollastonite. Examples include fillers, fibrous woven fillers such as glass fiber mats, and the like.

Among these, talc is most preferred from the comprehensive viewpoint of tear sheets such as heat resistance, mechanical properties such as flexural modulus, and workability, and the particle size is preferably in the range of 2 to 10 liters. If the particle size exceeds 10=, there is a concern that the impact strength will decrease, and if the particle size is less than 2 pL, it is preferable in terms of physical properties, but is expensive and economically disadvantageous.

The blending amount of the above inorganic filler can be appropriately selected within the range of 5 to 40% by weight based on the weight of the olefin polymer. If the blended amount of the inorganic filler is 5% by weight, the required physical properties such as heat resistance cannot be satisfied. On the other hand, 40
If the weight percentage is increased, there is a concern that the mechanical strength will decrease, which is not preferable.

The inorganic filler L can be blended using a conventional kneading machine such as a screw extruder, twin screw extruder, Banbury mixer, roll, or kneader.

Further, when the filler is made of a woven fabric such as a glass fiber mat, the woven fabric can also be manufactured by laminating the woven fabric with an olefin polymer in the form of a sandwich.

In the present invention, the above olefin polymer and inorganic filler are mixed in a desired ratio and formed into a sheet by a conventional method such as extrusion molding, a T-die method, or a calender method, and then the entire or desired portion of at least one side is formed into a sheet. embossing, sandblasting,
By roughening the surface by subjecting it to surface treatment such as corona discharge treatment, flame treatment, or plasma treatment, the coefficient of friction between one side and the other side of the tear sheet is made different, or the tear sheet surface is coated with ethylene-vinyl acetate copolymer, By laminating or laminating anti-slip materials such as synthetic rubber, containers can be easily stacked and transported to prevent cargo from slipping or collapsing.

The above coefficient of friction varies depending on the type of metal, glass, or plastic container, the shape of the container section, the weight of the container, etc., but when a roughened surface is used as a front, for example, Metal cans such as beer cans have a coefficient of static friction of 0.1 to 0.6. Preferably, a range of 0.2 to 0.5 is appropriate. Furthermore, depending on the type of container, it may be used with the roughened side facing down.

Furthermore, the thickness of the tear sheet of the present invention is 0.3 to 15
mm, preferably in the range of 0.5 to ioIms.

When the thickness of the tear sheet is less than 0.3+u+.

Mechanical strength such as sheet rigidity is poor, and the thickness is 15
If it exceeds mm, the physical properties required in the present invention are satisfied, but the weight increases, and there is a concern that automation and handling of cargo handling may be hindered.

The shape of the tear sheet of the present invention may be any suitable shape such as rectangular, square, oval, circular, etc. However, in the case of a shape with corners such as a rectangle or square, a portion of each corner will fit the shape of the container. It is desirable to attach a radius.

In addition, holes for drainage may be formed at desired locations on the tear sheet to the extent that required physical properties such as rigidity are not compromised, or fine irregularities may be processed during sheet forming to adjust the contact area with the container. - It is also possible to provide directionality when arranging the containers on the tray. Furthermore, if necessary,
When an antistatic agent is added, the tear sheet prevents the adhesion of dust, so it has a remarkable effect as a tear sheet for unfilled containers.

In the present invention, in addition to the above-mentioned additives, ordinary additives such as anti-oxidizing agents, lubricants, ultraviolet absorbers, flame retardants, dispersants, and crosslinking agents may be added.

As mentioned above, Tear Sea 1 of the present invention is water resistant, so it can withstand repeated use by washing and is not only hygienic, but also has a dust-proofing effect on unfilled containers and protects the containers. It facilitates stacking, improves work efficiency, and has heat resistance that allows high temperature sterilization and shrink packaging.

In addition, the tear sheet of the present invention has different surface properties (scratch resistance, gloss, flow mark, etc.), printability, and paintability depending on the type of inorganic filler added.

Adhesion, plating, tapping, and weld strength.

It can be expected to improve mechanical properties such as creep resistance and dimensional stability.

To, Example The present invention will be explained in more detail below using examples.

Example 1 Polypropylene homopolymer (MFI=1.0, trade name:
J120G, manufactured by Nippon Petrochemical ■) and 5% by weight of talc (
Product name: PK-C1 manufactured by Hayashi Kasei ■, average particle size top, moisture 0.13%, white scaly) was added and mixed.
Using an extruder (90mmφ), the sheet forming conditions were: resin temperature 250''C1 cooling roll temperature lOO℃, take-up speed 5m/win, thickness 1.O+w+sX length 144 length 144
0 width + sX width 1130- sheets were molded, and the surface of the sheet was further embossed to obtain a tear sheet.

On the embossed surface of the tear sheet, 3501 beer cans are arranged and loaded in 21 columns x 19 columns.

These cans are stacked in 14 stages on a plastic pallet, a tear sheet is placed on top of the top can, and a plastic top plate is placed on top of that. This was wrapped as one unit with a band and shrink-wrapped at 160° C. for 45 seconds, and the conditions were observed. The results are shown in Table 1.

The physical properties were tested in accordance with the test method below.

Item Test method Tensile test ASTM D638 Heating deformation temperature ASTM D648 Flexural modulus A・STM 0790 Eye impact strength ASTM D256 (notched,
23℃) The test pieces used in the above test were obtained by crushing each tear sheet and
Made by injection molding.

Injection molding conditions Injection pressure 1000 Kg/crn2 Injection time: 15 seconds.

Cooling time: 20 seconds.

Mold temperature: 50°C Resin temperature: 270°C Examples 2 to 5 The same tests as in Example 1 were conducted by adding the talc used in Example 1 to the resin used in Example 1 in various proportions. The results are shown in Table 1.

Comparative Example 1 Only the resin used in Example 1 was formed into a sheet in the same manner as in Example 1, and the same test was conducted.

The results are shown in Table 1.

Comparative Example 2 Polypropylene block copolymer (trade name: 3724,
Example 1 using Nippon Petrochemical Co., Ltd., MFI=1.5)
A sheet was prepared in the same manner as above and tested. The results are shown in Table 1.

Comparative Example 3 The same procedure as in Example 1 was carried out except that 45% by weight of the talc used in Example 1, which is outside the scope of the present invention, was added to the resin used in Example 1. The results are shown in Table 1.

As a result of adding a large amount of talc, the heat resistance improved, but the elongation and Izot impact strength were low and the product was brittle.

(1) Effects of the Invention As can be seen from the above description and examples, the tear sheet of the present invention has high rigidity and heat resistance strength, and also has good impact resistance. In addition, since it is made of plastic material, it is highly water resistant, washable and hygienic, can withstand repeated use, does not contaminate the container, and can be sterilized at high temperatures, so it can be used in shrink packaging or It has many features such as not bending or deforming when stored in stacks.

Patent applicant: Japan Petrochemical Co., Ltd. Agent Hajime Shima

Claims (4)

[Claims] (1) Olefin polymer and S machine filler 5-40%
A tear sheet consisting of a composition mainly containing a blend with (an olefin polymer) and having a coefficient of friction on one side larger than the coefficient of friction on the other side and having a thickness of 0.3 to 15 m5. (2) The tear sheet according to claim 81, wherein the entire or desired portion of at least one side of the tear sheet is roughened. (3) The tear sheet according to claim 1 or 2, wherein the olefin polymer is a propylene resin. (4) The tear sheet according to any one of claims 1 to 3, wherein the inorganic filler is talc.