JPS58102723A - Slip resistant polyolefin molded product - Google Patents

Abstract

PURPOSE:To provide a slip resistant product being excellent in durability, by a method wherein a slip resistant member, which is produced as a result of molding of a given polyolefin rubber in which a high-pressure process low-density polyethylene is mixed, is fusion-bonded by heat to a polyolefin molded product. CONSTITUTION:A mixture of 20-80wt% ethylene.propylene rubber A, i.e., an elastomer comprising 60-80wt% an ethylene component obtained as a result of polymerization of ethylene and propylene under the presence of a Ziegler catalyst, and 80-20wt% high pressure process low-density polyethylene B having a long chain branch[a density is not higher than about 0.94, a melt index (190 deg.C) is about 0.1-2.5g/(10min)]is molded to form a slip resistant member 2. Said slip resistant member 2 are positioned on a surface of a polyolefin molded product and are fusion-bonded by a hot blasting method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to anti-slip polyolefin molded articles. More specifically, it relates to a polyolefin molded product equipped with an anti-slip material that has an excellent anti-slip effect and good durability.

Polyolefin molded products have excellent water resistance, chemical resistance, etc., are hygienic, and have established standards for molded products, so they have come to be widely used in place of wood, metal, etc.

However, although this polyolefin molded product has the above-mentioned excellent features, it also has the drawback of being slippery. In particular, when pallets used for transporting and storing cargo are made from polyolefin molded products, slipping is prevented between the cargo and the pallet, between the pallet and the forks of a forklift, and between pallets. There is a risk of the load collapsing when transporting or transferring the load.

Conventionally, as a method to prevent the above-mentioned slippage,
Methods such as forming irregularities on the surface of molded products such as pallets and fitting rubber cleaning stops have been used, but these methods are still far from satisfactory in various respects.

The inventors of the present invention have conducted extensive studies in order to eliminate the above-mentioned drawback of conventional polyolefin molded products, such as their tendency to break, and as a result, they have developed an anti-slip material made of a special composition to be applied to polyolefin molded products with a specific configuration. They discovered that the problem could be solved by attaching them, and completed the present invention.

That is, the gist of the present invention resides in a polyolefin molded article obtained by thermally welding an anti-slip material made of a blend of ethylene propylene rubber and high-pressure low density polyethylene having long chain branches to the polyolefin molded article.

An example of the molded product of the present invention will be further explained below with reference to the drawings.

FIG. 1 is a perspective view of a pallet which is an example of the molded product of the present invention.

In the figure, l indicates a molded product (pallet) and λ indicates a non-slip material.

The synthetic resin constituting the molded product (pallet) of the present invention is:
Polyolefin resins such as polypropylene, polyethylene, polybutene-11 ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer are used in consideration of thermal weldability with the anti-slip material. Engineering 8 [
It is preferable that the hardness (according to 47θl) is 7 or more and close to 100. To put it more simply, it is Shore hardness (Hardness by Shore D [)
A hard polyolefin whose main component is polypropylene or polyethylene with a σ of 4σ or more, preferably 70 or more is preferable.

The polyolefin constituting the above-mentioned molded product may contain additives such as antioxidants, ultraviolet absorbers, heat stabilizers, antistatic agents, flame retardants, crosslinking agents, foaming agents, dye pigments, organic fillers, and inorganic fillers. It may also be used by adding and mixing agents, and molded products/
For molding, any conventional molding method such as injection molding, extrusion molding, cast molding, etc. may be used depending on the desired molded product.

When the molded product l is a pallet, a foaming agent is added to the above polyolefin to give a foaming ratio of 80 to 8! It is desirable to obtain a low-foaming injection molded product having a non-foaming layer on the surface layer at a magnification of about 1:2. Of course, it may be non-foamed. The locking material is obtained by molding a blend of ethylene propylene rubber and high-pressure low-density polyethylene having long chain branches.

Ethylene propylene rubber is a rubbery eyelid produced by polymerizing ethylene and propylene in the presence of a Ziegler catalyst. This ethylene propylene rubber has an ethylene component of 6θ
~! It is desirable to contain θ weight %, preferably 7 θ to lθ weight %.

Furthermore, high-pressure low-density polyethylene having long chain branches is one obtained by polymerizing ethylene alone or a mixture of etele/ and a small amount of copolymerization component using a high-pressure method, and has a density of 0.9μ or less, preferably 0. .92 r or less.

In addition, the melt index (790c) is 0.7~ko,
! Preferably, it is f//0 minutes.

Copolymerization components include vinyl acetate, ethyl acrylate, methyl methacrylate, diethyl maleate, etc.
The ratio is less than /θ weight.

The above-mentioned high-pressure low-density polyethylene is different from the linear low-density polyethylene developed in recent years, and has a molecular structure having many long chain branches in the molecule. A long chain branch is one having a much larger number of carbon atoms than a short chain branch, which is about 1 to 6 carbon atoms.

If we compare the physical properties of high-pressure low-density polyethylene with long chain branches and linear low-density polyethylene, the difference in viscosity average molecular weight will be clearly seen, and the melt index =
For example, high-pressure low-density polyethylene with long chain branches has a molecular weight of 30,000 to 30,000 yen or less, and linear low-density polyethylene has a molecular weight of about 70,000 to 10,000 yen.

As mentioned above, the anti-slip material is made of a blend of ethylene, propylene rubber, and high-pressure low-density polyethylene having long chain branches, and the blending ratio is such that ethylene propylene rubber is λo A-t o weight %, preferably 30 to 70% by weight, preferably 60 to 60% by weight, high-pressure low density polyethylene with long chain branching is IO-20% by weight, preferably 70 to 30% by weight, preferably 60 to 60 to 60% by weight
% by weight. Of course, the above-mentioned additives may be further added to this mixture.

Further, these mixtures may be mixed with the above-mentioned ethylene propylene rubber and a long chain branched rubber using a high pressure process and low density. As other thermoplastic synthetic resins, polyolefin resins are preferred.

Furthermore, a part of the above ethylene propylene rubber may be added to ethylene propylene/diene rubber, stereobutadiene rubber, acrylonitrile butadiene rubber, polybutadiene rubber, polyisoprene rubber, or Other synthetic rubbers such as chloroprene rubber, polyurethane rubber, and thiocol rubber may be used instead.

The anti-slip material is formed from the above-mentioned mixture into a desired shape such as a strip, string, plate, or block by a suitable molding method such as extrusion molding or injection molding.

As an anti-slip material, the hardness (hardness according to JIB K6JO/) is rIElm 7! in terms of anti-slip properties, welding properties, compression deformation, resistance to fist wear, etc. ~, Tx day Mutana, tensile strength 1 [(
, TI8 K67! Strength by tr-r/ (however, 20C
It is desirable that the temperature (at constant temperature) is to-2toky/ctll.

Heat welding is used to install the anti-slip material onto the molded product. For example, when the surface of the molded product L and the surface of the non-slip material λ are melted using hot air or a hot plate, both of them are still molten. A method of joining the two by crimping while in a state, molded product l
When molding by injection molding etc., a non-slip material is fixed at a predetermined position in the mold, the mold is filled with molten polyolefin, and the heat of fusion is used to mold the molded product.
A method of heat welding the anti-slip material and the anti-slip material, while extruding the anti-slip material from an extruder into a strip, string, etc.
In order to improve adhesion, preheating, oxidation treatment, etc. may be applied in advance), and a method of welding by pressing is used.

Usually, the anti-slip material is placed near the molded product, and hot air is blown onto both to melt the surface of the molded product and the surface of the anti-slip material, and the two are crimped together. used.

The welding conditions for this welding method vary depending on the temperature of the hot air, the volume of the hot air, the distance from the hot air outlet to the molded product and the anti-slip material, etc., and may be partially determined by the line speed. To explain this using an example of about m1n, hot air of about 6θo-r o o C (the temperature of the heater in the hot air generator) is blown onto the surface of the molded product and the surface of the anti-slip material, and the surface of the molded product and the slippery material are This is done by forming a molten layer on the surface of the stopper material, and pressing the molten parts together using a pressing roller or the like with a pressure of about 0, sky/cra or higher while both surfaces are in a molten state.

Next, the characteristics of the molded article of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Various physical properties described in the examples were measured by the following measurement methods.

(11 melt index: J-engine 8 to 6 full θ-t
It was measured at a constant temperature of 20 liters according to lK.

(2) Density: Same as above (3) Tensile strength 2 Same as above (
4) Elongation: Same as above (5
) y, roo peel strength: Width Owm, Thickness, 2M
Using a test piece with a length of approximately 2 θ- in which a non-slip material is welded to the base material, approximately half of the non-slip material in the length direction of the non-slip material is peeled off from the base material, and the peeled non-slip material is /100 In the folded state, the anti-slip material and one end of the base material are fixed to the chuck of the testing machine, and the anti-slip material is peeled from the base material at a constant speed of tOwm/min at a constant temperature of λ0C, and the force required for peeling is calculated. Read the value and display the average value in ky/cm.

(6) Angle: Attach an anti-slip material sheet with a thickness of λ and a length of $2 t on a surface plate, place a sheet made of polyethylene or polypropylene, and apply a load of /kg to the sheet. added. From this state, the angle at which the sheet that was lifted and placed on one side of the surface plate at a constant speed of t00wm1 starts to slide (angle with respect to the horizontal plane) was measured.

(8) Abrasion rate: Using a custom fabric abrasion tester manufactured by Mahayana Kagaku ■, a piece of sandpaper of No. 0 was brought into contact with a lint stopper material of length 3 fIIIK, width 20 mm, and thickness λ■.3. Apply a load of (7,j lb) and make a reciprocating motion with a stroker 0IIIl at a constant temperature of 100, and! θθ
The anti-slip material was worn by repeating 0 reciprocations, and the amount of wear was expressed as a weight percentage of the original weight of the anti-slip material.

In the table of Examples, ethylene propylene rubber [111PM
Among high-pressure low-density polyethylenes having long chain branches, ethylene homopolymer is abbreviated as "HPLDJ," and ethylene-vinyl acetate copolymer is abbreviated as "F, VAJ."

Example 1 - Coethylene propylene rubber (II!PM) (manufactured by Japan EP Rubber ■, ethylene propylene rubber IPOJF, ethylene content 7 g weight q/b) and high pressure low density polyethylene with long chain branching (ethylene single weight) (combination) (il
[PLD), (manufactured by Mitsubishi Chemical Corporation, Tubatic IF/
θ0, melt index (/ri0C): θ, Hiroλf
/ / 0 minutes, density: θ, ri xr/clI) as shown below.
Mix according to the proportions shown in the table and use an extruder (Tanabe Plastic Machinery ■,
VBJθ-koλ type extrusion type extrusion end dalmage type J0φ, L
/D:22. The pellets were made into pellets using a compression ratio (i, t), and then press molded to create a mysterious sheet with a thickness of λM and a length of tO, which was used as a stopper material.

(Al　Heat welding of polypropylene molded products.

Polypropylene (manufactured by Mitsubishi Yuka ■, Mitsubishi/-Prene BO
-r, melt index (2JOr): /,, 21
710 minutes, density: o, q t / eyll), thickness 3. ! ■、Length and width Kona θ■Plate-shaped body, J j O'Q,
u kj/ Cd! Heat welding was carried out by press molding under pressure conditions for minutes. The various physical properties of the obtained anti-slip material were
Shown in the table.

(1)) Heat welding to polyethylene molded products.

Low-pressure process high-density polyethylene (manufactured by Mitsubishi Chemical Corporation, Tubatic JVO4tOC, Melt Index (/?7p)
): S, θ, density Iθ, 96f/, n) thickness 3. ! The above-mentioned anti-slip material sheet is applied to the plate-shaped body of expansion length and 1i 2 j OIII, / ? o C, akg
/ad was thermally welded by press molding under conditions of pressurization for minutes. Table 7 shows various physical properties of the obtained anti-slip material.

Example 3~! The rows in which HPLD was replaced with ethylene-vinyl acetate copolymer (manufactured by Sumitomo Chemical Co., Ltd., Evatate D20 //, vinyl acetate content!% by weight) were molded with heat-welded anti-slip material in the same manner as in Example. Goods and friends. Various physical properties of the obtained anti-slip material are shown in Table 1.

Comparative Examples/~3 Using 9 ethylene propylene rubber or HPLD used in Examples, ethylene propylene rubber alone, HPl, D alone, or ethylene propylene rubber and HP outside the scope of the present invention
An anti-slip material prepared using a compound containing LD was treated in the same manner as in Example 1 to obtain a molded article with the anti-slip material heat-welded. Table 1 shows various physical properties of the obtained stain prevention material.

Example 6 Using the pellet of Example 3, the extruder was heated to a thickness of 2 m.
A belt-like sheet with a length of @20 swm/region was used as a non-slip material, and a pallet made of the same polypropylene as that used in Example 3'' was heated with a structure similar to that shown in Fig. 1 on the surface of the pallet. Welded. Heat welding is 700~
♂θθC (built-in heater temperature), air volume/2θl/
This was done by melting the anti-slip material and the surface of the pallet with hot air of 10 min, and pressing them together with a pressing force (roller linear pressure) of -kg/an.

The anti-slip material adhered well to the pallet, and its anti-slip properties were sufficient for practical use.

In this way, the polyolefin molded product with the anti-slip material of the present invention has good anti-slip properties between the products placed on the pallet, for example, when this molded product is used as a pallet for transporting cargo. Play.

In addition, it has excellent wear rate, welding strength, etc., making it a highly desirable material for practical use.

[Brief explanation of the drawing]

Figure 1 shows the molded product of the present invention! FIG. 2 is a perspective view of an example pallet. In the figure, / indicates a molded product (pallet), and λ indicates a non-slip material. Applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent Attorney Hase - (7 others)

Claims (6)

[Claims] (1) A slip-proof polyolefin molded product made by heat-welding a slip-prevention material made by molding a blend of ethylene propylene rubber and high-pressure low-density polyethylene having long chain branches to a polyolefin molded product. (2) Ethylene propylene rubber has an ethylene component of 60%
The polyolefin molded article according to claim 1, which contains a propylene component of ~10% by weight and a propylene component of ~20% by weight. (3) The blending (weight) ratio of ethylene propylene rubber and high-pressure low-density polyethylene having long chain branches is -θ
: r0 to rQ: Polyolefin molded article according to claim 1 or 2, wherein 4111 is 0. (4) Claims 1 to 3 characterized in that an edelene vinyl acetate copolymer copolymerized with vinyl acetate of 10% or less by weight is used as the high-pressure low-density polyethylene having long chain branches. The polyolefin molded article according to any one of the items. (5) The polyolefin molded article according to any one of Claim 1 Insulator≠ Φ, wherein the polyolefin is polypropylene. (6) The polyolein molded article according to any one of claims 1 to 1, wherein the polyolefin is polyethylene.