JPH10258490A - Polyolefinic resin molded item and pallet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a superior antislipping functions and low temperature characteristics by providing an antislipping member consisting of an ethylene-α- olefinic copolymer having specific characteristics. SOLUTION: For polyolefinic resin employed in a molded item, there is used, e.g., polypropylene, polyethylene, or the like. An ethylene-α-olefinic copolymer is of the type consisting of a copolymer of ethylene and with one or more kinds of 3-20C α-olefin, wherein the density is 0.86-0.91 g/cm<3> , M1 is 1-50 g/10 min, Mw/Mn to be an index of a molecular weight distribution is 1.8-3.0, and a branching number of comonomer is 20 pieces or more in carbon atoms of 1000. In addition, when a hexane soluble quantity is made log10 H<=30.9-34.3×ρ as H is a hexane soluble quantity (weight %) and (ρ) is density (g/cm<3> ), an extremely strong adhesive force is obtained. Also, for example, as substance is employed having a low brittle temperature of -70 deg.C or lower or a glass transition temperature of -50 deg.C or lower, resulting in small lowering of impact strength even at a low temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article of a polyolefin resin having a member having a function of preventing slippage on its surface.

[0002]

2. Description of the Related Art Polyolefin resins are used in many applications because of their various excellent properties, but their slipperiness is a drawback depending on the application. In order to solve this drawback, various anti-slip methods have been proposed in the past. Among them, an excellent anti-slip effect can be obtained by heat-sealing or fitting a flexible member to the surface of a molded product. It is known that it can be provided.

A typical example of a material which is suitable for the heat welding and has an anti-slip effect is a thermoplastic elastomer. For example, in the case of a polyolefin resin pallet, it is known that a member made of this thermoplastic elastomer is heat-welded to the pallet surface in order to prevent the pallet from slipping. As the member, a low-density polyethylene, an ethylene-vinyl acetate copolymer is used. , A string member made of an ethylene-ethyl acrylate copolymer (Japanese Patent Application Laid-Open No. 52-133639), a pallet body and a vulcanized resin of the same type, and a sheet member made of EPDM (Japanese Patent Application Laid-Open No. 54-115846) ,
A member made of a copolymer of ethylene and an α-olefin and polyethylene (Japanese Patent Application Laid-Open No. 54-14447) is mentioned.

[0004] The members made of these thermoplastic elastomers show relatively good heat-weldability to those containing high-density polyethylene as a main component, but have sufficient heat-weldability to those made mainly of polypropylene. Not shown. On the other hand, a member made of a thermoplastic elastomer blended with a polypropylene-based resin has improved heat welding properties, but has poor low-temperature characteristics and cannot be used for pallets and containers used even at low temperatures.

[0005] By the way, pallets and containers made of polyolefin-based resin are often pulverized and reused when they are old or partially damaged. Non-slip members that are heat-welded so that they do not peel off or that are fitted so that they do not come off easily are difficult to separate from the resin molded product body, so they are crushed together and reused. The stopper member is desirably made of a resin that has good compatibility with the resin of the molded article main body, has no trouble during kneading, and does not reduce the performance of the recycled resin.

[0006]

SUMMARY OF THE INVENTION The present invention provides a heat-sealing member having a function of preventing slippage and excellent in low-temperature properties under such circumstances, and preferably, a sufficient heat-sealing property even for a molded article of polypropylene. An object of the present invention is to provide a molded article of a polyolefin resin having a member having the following structure provided on the surface.

[0007]

Means for Solving the Problems The present inventor has conducted intensive studies to achieve the above object, and as a result, a specific ethylene-α-olefin copolymer has an anti-slip function and has a low-temperature property. The present invention has been found to be a member excellent in heat resistance, and a member exhibiting sufficient heat welding property even to a molded article of a polypropylene resin, thereby completing the present invention.

That is, the present invention relates to the following (1) to (4): (A) a molded article body made of a polyolefin resin;
A polyolefin resin molded article provided with a non-slip member made of an ethylene-α-olefin copolymer having the following characteristics. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms

Further, (A ') a molded article body made of a polypropylene resin or a polyethylene resin, and (B') a slide made of an ethylene-α-olefin copolymer having the following characteristics (1) to (5). An object of the present invention is to provide a polyolefin-based resin molded product in which a stopper member is provided by heat-sealing. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms. (5) The amount of hexane soluble matter (H, (% by weight)) and density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ Preferably, the ethylene-α-olefin copolymers of (B) and (B ′) are metallocene-based. It is manufactured using a catalyst.

Further, (A ") an ethylene-based resin having the following characteristics (1) to (5) produced using a (B") metallocene catalyst on a pallet body made of a polypropylene resin.
An object of the present invention is to provide a pallet in which an anti-slip member made of an α-olefin copolymer is provided by heat-sealing. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms. (5) The amount of hexane soluble matter (H, (% by weight)) and density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ

[0011] Further, an ethylene-based resin having the following characteristics (1) to (5) produced by using (B ") a metallocene catalyst on a pallet body made of (A '") polyethylene resin.
An object of the present invention is to provide a pallet in which an anti-slip member made of an α-olefin copolymer is provided by heat-sealing. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms. (5) The amount of hexane soluble matter (H, (% by weight)) and density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polyolefin resin used in the molded article body of the present invention includes polypropylene, polyethylene, polybutene-1, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, ethylene-vinyl acetate Copolymers and the like can be mentioned. Polypropylene or polyethylene is preferred from the viewpoint of the mechanical strength of the molded article, and polypropylene resin is more preferred from the viewpoint of weight reduction and Shore hardness. For example, for pallets and containers, it is preferable that polyethylene, polypropylene, or polypropylene is 75% by weight or more and the balance contains polyethylene or the like, and further, that the shore hardness A is 60 or more (according to ASTM D2240). Particularly, those having a Shore hardness A of 70 or more are preferable.

[0013] These resins may be produced by any method, but may be appropriately added with an antioxidant, an ultraviolet absorber, a heat stabilizer, an antistatic agent, a flame retardant, a dye pigment, an organic filler, an inorganic filler and the like. It is better to mix them. For molding the molded article body of the present invention, a known molding method such as injection molding can be used depending on a desired molded article.

Next, ethylene-α- used in the present invention is used.
Examples of the olefin copolymer include ethylene and C3 to C2.
It is obtained by copolymerization with at least one α-olefin of 0, and has the following characteristics (1) to (4). (1) The density is from 0.86 to 0.91 g / cm ³ , preferably from 0.87 to 0.89 g / cm ³ . If the density is less than 0.86 g / cm ³ , the mechanical strength decreases, which is not preferable. On the other hand, 0.91 g / cm ³
If it exceeds, the anti-slip effect decreases. The density is JI
It is measured according to SK-7112. (2) MI is 1 to 50 g / 10 min, preferably 1 to 5 g / 10 min for extrusion molding and 10 to 30 g / 10 min for injection molding. MI
However, those which deviate from the range of 1 to 50 g / 10 minutes are not desirable because of poor moldability. MI is JIS K-72.
It is measured according to 10. (3) Mw / Mn as an index of molecular weight distribution is 1.8 to 3.
0. If Mw / Mn exceeds 3.0,
It is difficult to obtain stable welding strength. Preferably, Mw / Mn in which the molecular state in the resin is more uniform is 1.8 to 2.
Five. Mw (weight average molecular weight) / Mn
(Number average molecular weight) is measured by the GPC method. (4) The number of branches of the comonomer is 20 or more, preferably 35 or more in 1,000 carbon atoms. It is presumed that those having a large number of branches have a high compatibility with the polyolefin resin, a high probability of the presence of tie molecules at the bonding interface, and a tendency to increase the welding strength. This value is
It is measured by ¹³ C-NMR.

As the above-mentioned ethylene-α-olefin copolymer, those having the characteristic (5) are preferable. (5) The amount of hexane-soluble component is represented by the following formula: log ₁₀ H ≦ 30.9−34.3 × ρ H: hexane-soluble component (% by weight), ρ: density (g / cm)
³ ) Satisfy. This is low in low molecular weight components and the like, which are considered to hinder welding.

The ethylene-α-olefin copolymer has a Shore hardness A in the range of 75 to 95,
Shore hardness D is in the range of 25 to 45 (ASTM D224
0). Usually, the ethylene-α-olefin copolymer satisfying the above (1) to (3) often satisfies this. Further, as the above-mentioned ethylene-α-olefin copolymer, those having a low-temperature embrittlement temperature of −70 ° C. or lower and a glass transition temperature of −50 ° C. or lower are more preferable. Those having such characteristics have a small decrease in impact strength even at low temperatures, and are optimal as anti-slip members for pallets and containers used at low temperatures.

As the above-mentioned ethylene-α-olefin copolymer, those produced using the following metallocene catalyst can be preferably used. Metallocene catalysts are disclosed in JP-A-58-19309 and JP-A-61-13.
No. 0314, JP-A-3-1630088, JP-A-4-300887, JP-A-4-21694, JP-T-1-502036 and the like, cyclopentadienyl group, substituted Transition metal compounds having one or two ligands, such as cyclopentadienyl group, indenyl group, substituted indenyl group, and the like, and transition metal compounds in which the ligands are geometrically controlled. It is characterized by having uniform properties. Preferred transition metals in these transition metal compounds include zirconium, titanium, and hafnium.

Specific metallocene catalysts include cyclopentadienyl zirconium trichloride, pentamethylcyclopentadienyl zirconium trichloride,
Bis (cyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dialkyl, indenyl zirconium trichloride, bis (indenyl) zirconium dichloride, dimethylsilylene-bis ( (Indenyl) zirconium dichloride, (dimethylsilylene) (dimethylsilylene)-
Bis (indenyl) zirconium dichloride, (dimethylsilylene) -bis (2-methyl-4-phenylindenyl) zirconium dichloride, (dimethylsilylene)
-Bis (benzoindenyl) zirconium dichloride,
Ethylene-bis (indenyl) zirconium dichloride, (ethylene) (ethylene) -bis (indenyl) zirconium dichloride, (ethylene) (ethylene) -bis (3-methylindenyl) zirconium dichloride,
(Ethylene) (ethylene) -bis (4,7-dimethylindenyl) zirconium dichloride, (tert-butylamide) (tetramethyl-η5-cyclopentadienyl)-
1,2-ethanediyl zirconium dichloride, (third
Tert-butylamido) dimethyl (tetramethyl-η5-cyclopentadienyl) silane zirconium dichloride, (methylamido) (tetramethyl-η5-cyclopentadienyl) -1,2-ethanediylzirconium dichloride and the like, and zirconium in these compounds Those substituted with hafnium or titanium can be given.

The co-catalysts used simultaneously include:
Those described in the above publications can be used. Preferred co-catalysts include linear or cyclic aluminoxanes (eg, methylaluminoxane), ionic compounds (eg, N, N-dimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetraphenylborate), Lewis acids (eg, triethylammonium). Examples thereof include boron compounds such as phenyl boric acid and tris (pentafluorophenyl) boric acid), and alkyl aluminum (eg, trialkyl aluminum such as triethyl aluminum and isobutyl aluminum).

As the polymerization method, any method such as a gas phase method and a solution method may be used. Further, the monomer used for the polymerization is ethylene and one or more α-olefins having 3 to 20 carbon atoms. As the α-olefins having 3 to 20 carbon atoms, propylene, butene-1, pentene-1, 4-methyl Penten-1, hexene-1, peptene-1, octene-1, nonene-1, decene-1 and the like. Preferably, it has 4 to 10 carbon atoms. From the viewpoint of weldability and the like, more preferred are those having 6 to 10 carbon atoms.

The shape of the non-slip member of the present invention is not particularly limited, but when it is provided on the upper and lower surfaces of the pallet, a fork contact surface such as a fork insertion hole, the lower surface of a container, the lower surface of a container, or the like, It is preferable to use the ethylene-α-olefin copolymer obtained in the form of a sheet and a strip or string. Usually, the thickness is 0.5-3mm
And the width greatly depends on the shape of the molded product, but is 3 to 30
mm. In the case of a pallet or the like, a groove-shaped portion shallower than the thickness of the member is provided at the member mounting position on the body surface,
It is preferable to provide a member there because positioning becomes easy.

When provided on a handle or the like of sports equipment, the surface of the handle itself may be formed of the above-described copolymer, or the above-mentioned band or string may be wound around the handle. It may be used as follows. The method of providing the non-slip member on the molded article body of the present invention includes a method of welding, a method of fitting and mounting, and a method of using an adhesive. The mounting method is preferable. In particular, a welding method that has good attachment work efficiency and enables strong adhesion is preferable.

As a method of welding the molded article body and the member, any method capable of melting a contact interface corresponding to a welded portion can be adopted. More specifically, hot plate welding, hot air welding, dielectric heating welding, which is applied while applying heat to melt the welding surface, and vibration welding, ultrasonic welding, or micro welding, in which the contact surface is heated and welded by vibration or ultrasonic energy. High-frequency welding using wave energy can be used.

In the present invention, since the above-mentioned copolymer is used for a member, a very strong welding force can be obtained, and the amount of molten resin at the contact interface can be reduced. You. This is because the copolymer of the member has many branched comonomer components having high compatibility with the polyolefin-based resin, and because the hexane-soluble component is small, there is little precipitation of components that hinder welding on the welding surface. Guessed.

A well-known method can be adopted as a method of fitting and mounting. It may be appropriately selected in consideration of the size of the member and the strength of the fitting portion within a range satisfying the characteristics of the copolymer. In addition to the above, the polyolefin resin of the molded article body of the present invention and the above-mentioned copolymer of the anti-slip member are excellent in dispersibility and compatibility at the time of melt-kneading, and have a large amount of solubility. Therefore, when the molded article is recycled, there is no problem in reusing the molded article body and the member together as a recycled resin even if the molded article body and the member are crushed together and re-pelletized. Rather, it can be expected to act as a modifier for recyclable resins whose impact strength has decreased due to aging.

[0026]

EXAMPLES Next, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to these examples. [Example 1 and Comparative Examples 1 and 2] Mode manufactured by Branson Corporation
A welding test of a polypropylene-based resin plate and the following sheet was performed using a 1 · 2700 welding machine.

As a polypropylene resin plate, Idemitsu Petrochemical's IDEMITU PP J762HP (ethylene content: 10%, MI = 12 g / 10 min (230 ° C.,
4 m thickness obtained by injection molding with a load of 2.16 kg))
m plate was used. Further, as a sheet made of an ethylene-α-olefin copolymer corresponding to a non-slip member, in the example, HM1100 manufactured by Dow Chemical (density = 0.8)
8 g / cm ³ , MI = 16.6 g / 10 min (190 ° C.,
Load: 2.16 kg), Mw / Mn = 2.3, number of comonomer branches = 45/1000 carbon atoms, hexane soluble content =
0.8% by weight) and a sheet having a thickness of 2 mm obtained by extrusion molding was used.

In Comparative Example 1, EVA EV450 (vinyl acetate: 20%) manufactured by DuPont-Mitsui Chemicals was used.
In Comparative Example 2, Idemitsu Petrochemical IDEMITU LL
1014T (density = 0.91 g / cm ³ , MI = 10 g
/ 10 min (190 ° C, load 2.16 kg), Mw / Mn
= 3.2, the number of branches of the comonomer = 27/1000 carbon atoms), and a sheet having a thickness of 2 mm obtained by extrusion molding was used.

Table 1 shows the welding conditions and the results of the welding conditions. When the propylene-based resin plate of Example was welded to a sheet, the slip property between the sheet surface and another propylene-based resin plate was evaluated. As a result, it was found that the sheet had a sufficient anti-slip effect. Furthermore, even at a low temperature of -30 ° C,
There was no change in the welding state, and the low-temperature characteristics were also good.

[0030]

[Table 1]

Example 2 A pallet manufactured using the same polypropylene resin (J762HP) as in Example 1 was provided on both sides with a belt-like sheet (thickness 2 mm) made of the same ethylene-α-olefin copolymer as in Example 1. , 20 mm in width, 1 m in length). In this heat fusion, the surface of the pallet at the welding portion is melted by blowing hot air at 500 to 600 ° C., and then the sheet is melted by the heat, and is pressed onto the pallet with a pressing force of 5 to 15 kg / cm ^2. It was done by pressing.

It was found that the strip-shaped sheet was sufficiently thermally welded to almost the entire surface. Further, in a practical evaluation performed with a beer bottle container placed on the pallet and using a forklift, the beer bottle container was not rubbed, and a sufficient anti-slip effect was confirmed. Further, in the practical evaluation at a low temperature of -30 ° C., no abnormality such as a crack was found in the belt-shaped sheet, the welded state was not changed, and the low-temperature characteristics were good.

[0033]

The polyolefin resin molded article and pallet of the present invention exhibit good anti-slip effect and low-temperature characteristics. Further, in the molded product obtained by thermal welding, by using a specific ethylene-α-olefin copolymer for the non-slip member, the molded product of the polypropylene-based resin exhibits good thermal welding properties. Thereby, it is useful for molded articles for distribution such as pallets, sporting goods, and the like.

Claims (6)

[Claims] (1) A non-slip member made of an ethylene-α-olefin copolymer having the following characteristics (1) to (4) is provided on a molded article body made of a polyolefin resin (A). Polyolefin resin molded article characterized by the following. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms 2. The polyolefin resin molded article according to claim 1, wherein the ethylene-α-olefin copolymer (B) is produced using a metallocene catalyst. 3. A molded article body comprising (A ') a polypropylene resin or a polyethylene resin, wherein (B') the following (1):
A polyolefin resin molded article characterized in that a non-slip member made of an ethylene-α-olefin copolymer having the characteristics of (5) to (5) is provided by heat-sealing. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms. (5) The amount of hexane soluble matter (H, (% by weight)) and density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ 4. The polyolefin resin molded article according to claim 3, wherein the ethylene-α-olefin copolymer (B ′) is produced using a metallocene catalyst. 5. An ethylene-α-olefin copolymer having the following characteristics (1) to (5) produced by using (A ″) a pallet body made of a polypropylene resin and (B ″) a metallocene catalyst. A pallet, wherein a non-slip member made of a united body is provided by heat-sealing. (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g / 10 minutes (3) The Mw / Mn is 1.8 to 3.0 (4 ) The number of branches of the comonomer is 20 or more per 1000 carbon atoms. (5) The amount of hexane soluble matter (H, (% by weight)) and density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ 6. An ethylene-α-olefin having the following characteristics (1) to (5) produced by using a metallocene catalyst (B ″) on a pallet body made of a polyethylene resin (A ′ ″): A pallet comprising a non-slip member made of a copolymer which is provided by heat fusion (1) The density is 0.86 to 0.91 g / cm ³ (2) The MI is 1 to 50 g (3) Mw / Mn is 1.8 to 3.0 (4) The number of branches of the comonomer is 20 or more in 1000 carbon atoms (5) The amount of hexane soluble matter (H, (weight %)) And density (ρ
(G / cm ³ )) satisfies the following equation: log ₁₀ H ≦ 30.9−34.3 × ρ