JP3487916B2 - Ethylene copolymer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ethylene copolymer composition having excellent scratch resistance, stain resistance, slipperiness, moldability and the like, and more particularly to a flexible material which can be suitably used for a bumper for household appliances.

[0002]

Bumpers used in vacuum cleaners,
As a material for the suction port bumper, etc., it has excellent scratch resistance, and when it hits furniture or pillars during cleaning, it does not easily damage them, so soft vinyl chloride resin (PV
C) is frequently used. However, in addition to the adverse effects of the transfer of plasticizer to other base materials, which have been pointed out in the past, soft PVC is accompanied by the generation of corrosive gas during combustion, making it difficult to recycle plastics. There is a strong demand.

Polymers mainly composed of olefins do not have such drawbacks. Among them, ethylene copolymers obtained by copolymerizing a predetermined amount of copolymerization components are expected as an alternative material because they are flexible and lightweight. To be done. However, many of them lack scratch resistance, stain resistance, heat resistance, etc. themselves, or cause resin transfer to the furniture to contaminate it when it hits furniture, etc., or furniture, pillars, etc. Due to the lack of slipperiness with respect to the vacuum cleaner, it is difficult to move the vacuum cleaner to reduce workability, and there is a problem that furniture and the like are damaged. Further, many of them have a problem that the mold release is poor and the productivity is poor when the bumper is manufactured by injection molding.

[0004]

Therefore, the present inventors have found that
An investigation was conducted to find a material that does not have these defects or difficulties and exhibits excellent performance as a bumper. As a result, they have found that the following ethylene copolymer composition has desired performance, and have reached the present invention.

Accordingly, an object of the present invention is to produce an ethylene copolymer composition which does not generate a toxic gas at the time of combustion and is excellent in scratch resistance, stain resistance, slipperiness, injection moldability and the like and which is suitable as a cleaner bumper material. To provide.

[0006]

That is, according to the present invention, the ethylene content is 60 to 90% by weight, 190 ° C., 2160 g.
Melt flow rate under load is 0.1-100g /
10 minutes ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or its ionomer (A) 1
Silicone polymer (B) 0.1-2 with respect to 00 parts by weight
The present invention relates to an ethylene copolymer composition containing 0.1 part by weight and 0.1 to 10 parts by weight of a hydrocarbon wax (C).

[0007]

In the present invention, a copolymer of ethylene, (meth) acrylic acid and (meth) acrylic acid ester, or a copolymer thereof, is used as the main component (A) of the ethylene copolymer composition used for applications such as vacuum cleaner bumper materials. An ionomer (ionic crosslinked polymer) is used. Here, (meth) acrylic acid means acrylic acid or methacrylic acid.

This copolymer has an ethylene content of 60 to
The (meth) acrylic acid and the (meth) acrylic acid ester are contained in the copolymer under the condition of being in the range of 90% by weight. (Meth) acrylic acid is effective for imparting scratch strength, while (meth) acrylic acid ester is effective for imparting flexibility and elasticity. Among the copolymers, those having an ethylene content of more than 90% by weight are not preferable because the hardness is too high and the furniture or the like is easily damaged when used as a vacuum cleaner bumper. On the other hand, when a copolymer having an ethylene content of less than 60% by weight is used, scratch resistance, heat resistance and the like are insufficient, which is not practical.

This ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer (A) is
Melt flow rate at 2160g load is 0.1
It should be in the range of 100 g / 10 minutes, and if the value is extremely small, the fluidity in injection molding is poor and it becomes difficult to mold a component having a complicated shape. Further, if the value is extremely large, the strength of the resin is lowered, which is not preferable in terms of physical properties.

It is possible to mix 0.1 to 2 parts by weight of the silicone polymer (B) and 0.1 to 10 parts by weight of the hydrocarbon wax (C) with 100 parts by weight of the ethylene copolymer (A) in combination. , Is important in maintaining the slipperiness over time. If the amount of the silicone polymer (B) used is less than the above range, it is difficult to obtain a composition having sufficient slipperiness, and in the case of injection molding, the releasability from the mold becomes poor. On the other hand, if the amount is too large, slippage easily occurs in the screw during melt molding, which makes molding difficult, which is not preferable. Similarly, when the amount of the wax (C) used is small, the moldability is deteriorated, and when the amount of the wax (C) is too large, the wax becomes too hard, which is not preferable.

From the above, scratch resistance, stain resistance,
It is possible to provide an ethylene copolymer composition which is excellent in slipperiness and injection moldability and is suitable as a cleaner bumper material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer which can be used as the component (A) in the present invention has an ethylene content of 60 to
90% by weight, preferably 65-85% by weight, so that the total content of (meth) acrylic acid and (meth) acrylic acid ester is 10-40% by weight, preferably 15-35.
% By weight. Among the copolymers, those having an ethylene content of more than 90% by weight are not preferable because the hardness is too high and the furniture or the like is easily damaged when used as a cleaner bumper. On the other hand, when a copolymer having an ethylene content of less than 60% by weight is used, scratch resistance, heat resistance and the like are insufficient, which is not practical. Of the copolymerization components,
The (meth) acrylic acid content is about 2 to 20% by weight, particularly about 4 to 15% by weight, and the (meth) acrylic acid ester content is about 8 to 35% by weight, particularly about 10 to 30% by weight. Is desirable. Of these, (meth) acrylic acid is effective for imparting scratch strength, but if the amount is too large, the resulting molded article will be too hard.

Examples of the (meth) acrylate ester in the copolymer include methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, 2-ethyl-hexyl acrylate, methyl methacrylate, isobutyl methacrylate and the like. Is. Examples of the copolymer include ethylene / acrylic acid / methyl acrylate copolymer, ethylene / acrylic acid / ethyl acrylate copolymer, ethylene / acrylic acid / isobutyl acrylate copolymer, ethylene / methacrylic acid / acrylic. Representative examples are methyl acid copolymer, ethylene / methacrylic acid / ethyl acrylate copolymer, ethylene / methacrylic acid / isobutyl acrylate copolymer, ethylene / methacrylic acid / n-butyl acrylate copolymer. You can

Such a copolymer can be obtained by radical-copolymerizing each polymerization component under high temperature and high pressure.

As the component (A) of the present invention, an ionomer in which a part of the carboxyl groups of the ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer is neutralized with a metal ion is used. can do. Typical examples of the metal ion in the ionomer include lithium, sodium, potassium, magnesium, calcium, zinc and the like. Especially scratch resistance (the bumper itself is not damaged),
It is preferable to use an ionomer in order to improve abrasion resistance (the bumper material does not fuse to the furniture and the like when the bumper and the furniture and the like rub against each other). A suitable degree of neutralization in the ionomer depends on the (meth) acrylic acid content of the base copolymer, but is generally 80 mol%.
It is preferably 50 mol% or less. If the neutralization degree is too high, the hardness may be too high.

The component (A) has a melt flow rate of 0.1 to 100 g / 10 minutes, preferably 1 to 30 g /
Use the one for 10 minutes. If a material having a very small value is used, the fluidity when injection molding is poor, and it becomes difficult to mold a component having a complicated shape. Further, if the value is extremely large, the strength of the resin is lowered, which is not preferable in terms of physical properties. As the component (A), J at 23 ° C.
It is preferable to use one having an ISA hardness of 70 to 95, especially 75 to 90.

The silicone polymer (B) used in the present invention is an organopolysiloxane or a modified product thereof, and typical examples thereof include dimethylpolysiloxane and phenylmethylpolysiloxane.
Examples of the modified product include polyether modified products and fatty acid modified products. As the silicone polymer, one having a viscosity at 25 ° C. of 50 centistokes or more, particularly 1000 centistokes or more is preferable. Such a silicone polymer, when used,
Those supported on an inorganic filler such as silica may be used, or various ethylene copolymers, plastics such as low / medium / high density polyethylene, polypropylene, polystyrene, and the like mixed in advance at a high concentration may be used. Good. Such a solid product is available as a commercial product and can be preferably used since it is particularly easy to mix with other components.

In the present invention, a hydrocarbon wax (C) is used together with the silicone polymer (B).
Examples of the hydrocarbon wax include paraffin wax, microcrystalline wax, various polyethylene waxes, Fischer-Tropsch wax, polypropylene wax and the like. As these waxes, those which have been modified by oxidation or maleation may be used. As the wax (C), one having a ring and ball softening point of 60 to 160 ° C., particularly 80 to 150 ° C. is preferably used.

The amount of the silicone polymer (B) used is 0.1 to 2 parts by weight based on 100 parts by weight of the ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or the ionomer (A). , Preferably 0.2 to 1 part by weight. The amount of wax (C) used is the same as component (A) 1
It is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 00 parts by weight. If the amount of the silicone polymer (B) used is less than the above range, it is difficult to obtain a composition having sufficient slipperiness, and in the case of injection molding, the releasability from the mold becomes poor. On the other hand, if the amount is too large, slippage easily occurs in the screw during melt molding, which makes molding difficult, which is not preferable. Similarly, when the amount of the wax (C) used is small, the moldability is deteriorated, and when the amount of the wax (C) is too large, the wax becomes too hard, which is not preferable.

Instead of such a silicone polymer (B) and a hydrocarbon wax (C), a fatty acid amide, polyethylene glycol or the like which is generally used as a release agent or a slipperiness imparting agent for molded articles is used. Can not achieve a satisfactory effect. For example, with polyethylene glycol, the desired releasability cannot be obtained, and when a fatty acid amide is used, the slipperiness tends to be lost over time.
The combined use of (C) and (C) can specifically obtain a desired effect.

Various additives can be added to the ethylene copolymer composition of the present invention. Examples of such additives include antioxidants, heat stabilizers, antistatic agents, pigments, dyes, and inorganic fillers.

For example, in order to improve releasability at the time of injection molding,
It is effective to add a small amount, for example, up to 20 parts by weight, preferably about 1 to 15 parts by weight, of an inorganic filler per 100 parts by weight of the component (A). As such an inorganic filler, talc, clay, silica, calcium carbonate, magnesium carbonate, hydrotalcite, magnesium hydroxide, barium sulfate, zinc oxide, titanium oxide, glass powder,
Examples thereof include glass fiber, carbon black, carbon fiber and the like. These inorganic fillers may be surface-treated, or may be pre-blended with a wax such as wax (C). Calpet A (manufactured by Nitto Koka Co., Ltd.) is an example of such a product.

In order to obtain the ethylene copolymer composition of the present invention, each component may be melt-kneaded by using a melt-kneading device such as an extruder or a Banbury mixer. When each component can be handled in a solid state, it is possible to dry-blend these components and use a direct injection molding machine to obtain a molded article comprising the composition of the present invention.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples. The preparation of test square plates and the method for evaluating the physical properties thereof in Examples and Comparative Examples are as follows.

1. Preparation of Sample (1) Addition of Additives Ethylene / methacrylic acid / isobutyl acrylate copolymer which is a component of the resin composition of the present invention is mixed with 50% dimethyl silicone polyethylene MB, polyethylene wax, calcium carbonate (inorganic filler ) And other additives were melt-kneaded with a twin-screw extruder to obtain a pelletized blend. (2) Molding of test square plate A square plate (length x width x thickness, 120 x 120 x 2 mm) for testing was molded from the resin composition melt-kneaded as above using an injection molding machine. The mold temperature was 20 ° C. The molding temperature was set as follows. Ionomer of ethylene / methacrylic acid / isobutyl acrylate copolymer: 190 ° C ethylene / methacrylic acid / isobutyl acrylate: 180 ° C polyvinyl chloride: 180 ° C (3) Making a press sheet A predetermined amount of the resin composition is heated. After preheating with a pressing machine at 160 ° C. for 5 minutes, the pressure was further increased to 100 ° C./cm ² at 160 ° C. for 5 minutes, and after cooling, a 3 mm thick press sheet was prepared.

2. Evaluation Method of Molded Sample Square Plate (1) Hardness JISA hardness was measured at room temperature using a press sheet having a thickness of 3 mm based on JIS K6301. (2) Formability The ease of releasing the square plate mold during square plate molding was judged using five-level indexes. ◎ Good mold releasability ○ Good mold releasability △ Good mold releasability Normal (similar to current PVC) × Mold releasability × Poor × × Mold releasability Difficulty (3) Sliding property The slipperiness of the square plate at room temperature was evaluated 24 hours after the square plate was formed, using five-level indexes. ◎ Sliding property is good ○ Sliding property is slightly good △ Sliding property is normal (similar to current polyvinyl chloride) × Sliding property is somewhat unsatisfactory ×× Sliding property is unsatisfactory After some aging in a 50 ° C oven for 14 days Was also evaluated for slipperiness. (Implemented in Comparative Example 6) (Implemented in Example 4) (4) Scratch resistance Square plate molding After 24 hours or more, the comprehensive evaluation of scratches and rubbing properties of the rectangular plate is judged by five-stage index. did. -Scratchability: The square plate was rubbed with a nail and the scratchability was visually evaluated.・ Rubbing ability ... Rub the square plate against the steel coating plate,
The degree of resin sticking to the steel coated plate was visually evaluated. ◎ Scratch resistance is good ○ Scratch resistance is somewhat good △ Scratch resistance is normal (like current PVC) × Scratch resistance is somewhat poor × × Scratch resistance is bad (5) Density Part of 3mm press sheet according to JIS K6760 Was used to measure the density of the resin composition at room temperature.

Example 1 Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 8 g /
Polyethylene MBBY27-00 containing 89.4 parts by weight of ionomer of ethylene / methacrylic acid / isobutyl acrylate copolymer for 10 minutes and 50% of dimethyl silicone
0.6 parts by weight of 2 (made by Toray Dow Silicone), 8 parts by weight of calcium carbonate (made by Nitto Koki) and polyethylene (PE)
An injection square plate and a press sheet were prepared using a resin composition containing 2 parts by weight of wax 210M (manufactured by Mitsui Petrochemical Co., Ltd.),
Various physical properties such as mold releasability and slipperiness were measured. The results are shown in Table 1.
And shown in Table 2.

[Example 2] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
/ 10 min ethylene isobutyl acrylate copolymer 8
An injection plate and a press sheet were prepared using the resin composition having the same formulation as in Example 1 except that 9.4 parts by weight was used, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Tables 1 and 2.

[Example 3] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 8 g /
Polyethylene MBBY27-00 containing 95.4 parts by weight of ionomer of ethylene / methacrylic acid / isobutyl acrylate copolymer for 10 minutes and 50% of dimethyl silicone
2 (manufactured by Toray Dow Silicone) and 4 parts by weight of PE wax 210M (manufactured by Mitsui Petrochemical Co., Ltd.) were used to prepare injection square plates and press sheets, and mold releasability was obtained. Various physical properties such as slipperiness were measured. The results are shown in Tables 1 and 2.

[Example 4] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
/ 10 min ethylene / methacrylic acid / isobutyl acrylate copolymer 97.4 parts by weight and PE wax 210M
(Mitsui Petrochemical Co., Ltd.) 2 parts by weight was added, and the other additives had the same formulation as in Example 3. The results are shown in Table 3.

[Comparative Example 1] An injection square plate and a press sheet were prepared using polyvinyl chloride, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Tables 1 and 2.

Comparative Example 2 Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
Using 100 parts by weight of an ethylene / methacrylic acid / isobutyl acrylate copolymer of / 10 min, an injection plate and a press sheet were prepared, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Tables 1 and 2.

[Comparative Example 3] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 8 g /
100 parts by weight of an ionomer of an ethylene / methacrylic acid / isobutyl acrylate copolymer for 10 minutes was used to prepare an injection plate and a press sheet, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Tables 1 and 2.

[Comparative Example 4] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
/ 10 minutes ethylene / methacrylic acid / isobutyl acrylate copolymer 99.4 parts by weight and dimethyl silicone-containing polyethylene MB BY27-002 (manufactured by Toray Dow Silicone) 0.6 parts by weight An injection square plate and a press sheet were prepared, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Tables 1 and 2.

[Comparative Example 5] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 8 g /
Polyethylene MBBY27-00 containing 89.9 parts by weight of ionomer of ethylene / methacrylic acid / isobutyl acrylate copolymer for 10 minutes and 50% of dimethyl silicone
2 (manufactured by Toray Dow Silicone Co., Ltd.) was used in the same formulation as in Example 1 except for 0.05 parts by weight. The results are shown in Tables 1 and 2.

Comparative Example 6 Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
/ 10 min ethylene / methacrylic acid / isobutyl acrylate copolymer 98 parts by weight and N-oleyl palmitoamide 17%, 3.0 parts by weight of polyethylene masterbatch (PNT68, manufactured by Nippon Seika Co., Ltd.) An injection square plate and a press sheet were prepared using the compounded resin composition, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Table 3.

[Comparative Example 7] Methacrylic acid content 8%, isobutyl acrylate 20%, melt flow rate 25 g
Using a resin composition in which 99.7 parts by weight of an ethylene / methacrylic acid / isobutyl acrylate copolymer for 10 minutes and 0.3 parts by weight of polyethylene glycol MW4000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were blended, An injection square plate and a press sheet were prepared, and various physical properties such as mold releasability and slipperiness were measured. The results are shown in Table 3.

[0038]

[Table 1] Resin ethylene / methacrylic acid / isobutyl acrylate copolymer 35% Zinc ionized product (8% methacrylic acid, isobutyl acrylate 20%) Resin ethylene / methacrylic acid / isobutyl acrylate copolymer (methacrylic acid 8%, isobutyl acrylate 20%)

[0039]

[Table 2]

[0040]

[Table 3]

In the results of Tables 1 and 2, Comparative Example 1 currently used as a bumper material for home electric appliances has a large specific gravity, and since it is made of polyvinyl chloride, there is a problem that hydrogen chloride gas is generated during combustion. .

In Comparative Example 2 in which only the ethylene / methacrylic acid / isobutyl acrylate copolymer was used and in Comparative Example 3 in which only the ionomer of the ethylene / methacrylic acid / isobutyl acrylate copolymer was used, mold releasability and slippage were observed. The sex was poor.

In Comparative Example 4, only the silicone was added to the resin composition, but the mold releasability was slightly inferior.

In Comparative Example 5, 0.05 part of silicone was blended, but the slipperiness was poor. This is probably because the blending amount of the silicone polymer was small.

On the contrary, from the resin composition prepared according to the present invention, a molded article having good slipperiness, scratch resistance and mold releasability was obtained. These were equivalent or superior to the current product, Comparative Example 1.

In the results of Table 3, in Comparative Example 6 using N-oleyl palmitoamide as a releasing agent and a slipperiness imparting material for the resin, the slipperiness after 24 hours of molding was good, and the oven was kept at 50 ° C. After 14 days of aging, sufficient slipperiness was not obtained. This is because the amide compound distributed on the surface entered the inside of the resin,
It is presumed that the slipperiness could not be obtained.

Further, in Comparative Example 7 in which polyethylene glycol was used as a mold release agent for the resin, sufficient mold releasability could not be obtained during square plate molding.

On the contrary, it has been found that the system in which the silicone polymer of the present invention and the hydrocarbon wax are blended can obtain sufficient mold releasability even by oven aging.

[Table 4]

[0049]

According to the present invention, it is possible to provide a composition having excellent flexibility, scratch resistance, abrasion resistance, slipperiness, moldability and the like. Therefore, it can be suitably used as a bumper material for home electric appliances, especially a vacuum cleaner. Conventional soft P
It can be similarly used in various applications in which VC is used, such as a sheet, a tube, an extrusion molded article, an injection molded article and the like.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 91:06) (C08L 23/26 83:04 91:06)

Claims (4)

(57) [Claims] 1. An ethylene content of 60 to 90% by weight, 19
The silicone weight is 100 parts by weight of ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or its ionomer (A) having a melt flow rate of 0.1 to 100 g / 10 min at 0 ° C. and a load of 2160 g. 0.1 to 2 parts by weight of coalesced (B) and hydrocarbon wax (C)
An ethylene copolymer composition comprising 0.1 to 10 parts by weight. 2. The ethylene copolymer composition according to claim 1, further comprising 20 parts by weight or less of an inorganic filler with respect to 100 parts by weight of (A). 3. The ethylene copolymer composition according to claim 1, which is used as a bumper material for household appliances. 4. A bumper for home electric appliances, comprising the ethylene copolymer composition according to claim 1.