JP3368996B2 - Automotive soft resin bumper and its coated body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft resin bumper for an automobile and a coated body thereof, and more particularly, it has excellent appearance (weld, flow mark) and dimensional stability (low linear expansion) and low temperature impact resistance. TECHNICAL FIELD The present invention relates to a bumper made of a soft resin for automobiles which is excellent in balance between flexibility and flexibility and paintability and a coated body thereof.

[0002]

2. Description of the Related Art In recent years, in automobile bumpers, due to needs for size increase, weight reduction, and design flexibility, the material has been changed from steel to resin.

Urethane bumpers were the mainstream at the beginning of the resinization of bumpers, but nowadays, bumpers made of olefinic resins are the mainstream due to the performance improvement of cheaper olefinic resins. The olefin resin for bumpers is
It is roughly classified into two types: a low-rigidity type that has excellent low-temperature impact resistance and excellent deformation recovery after collision, and a high-rigidity type that has poor deformation recovery but low cost and excellent dimensional stability.

High-rigidity type olefin resins are disclosed in JP-A-57-55952 and JP-A-58-111846.
JP-A-59-98157 and JP-A 2-1.
As disclosed in Japanese Patent No. 66870, Japanese Unexamined Patent Publication No. Hei 2-166869, etc., in order to improve high rigidity and low temperature impact resistance, improvements have been made in terms of composition and composition.

On the other hand, the low-rigidity type olefin resin is disclosed in JP-A-53-145857 and JP-A-54-1.
6554, JP 57-13584, JP 56-106948, and JP 63-14695.
As disclosed in Japanese Patent Application Laid-Open No. 1-62117 and Japanese Patent Application Laid-Open No. 4-62117, in addition to rigidity and impact resistance, in order to improve the appearance (flow marks, welds, etc.) and dimensional stability of the molded product, the composition and the mixing surface are improved. Has been improved.

However, conventional injection-molded articles using the above-mentioned olefinic resin do not have polar groups in the resin itself, and therefore, when the coating material is directly applied, sufficient adhesion strength cannot be obtained, and the primer cannot be obtained. Coating or plasma treatment, pretreatment such as corona treatment was required. Further, in the application of the primer, there is a problem that an expensive primer must be used and the number of coating steps increases, and further, it is necessary to consider the management of the volatile component of the primer solvent from the viewpoint of safety. .

On the other hand, in the plasma treatment and the corona treatment, there is a problem that an increase in cost cannot be avoided due to the batch system in addition to the introduction of expensive equipment.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and is excellent in appearance and dimensional stability, and has a balance between low temperature impact resistance and flexibility and coating. An object of the present invention is to provide a soft resin bumper for automobiles having excellent properties and a coated body thereof.

The soft resin bumper for automobiles according to the present invention has (a) a propylene content of 85 mol% or more and a melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) of 20 to.
50-65 parts by weight of 100 g / 10 min propylene-based polymer, and (b) ethylene-α having an ethylene content of 30-98 mol%.
-Olefin copolymer 50 to 35 parts by weight [the total amount of the components (a) and (b) is 100 parts by weight], and (c) talc 1 to 10 having an average particle size of 1.0 to 2.5 μm.
And (e) a propylene-based polymer (e-1) having a carboxyl group or an acid anhydride group in the molecule, and an amino compound (e-).
2) A propylene polymer having 0.1 to 30 parts by weight of a polar group-containing propylene polymer having an intrinsic viscosity of 1.0 dl / g or less measured in decalin at 190 ° C. And (I) the flexural modulus measured at 23 ° C. is 4,000 to 7,
000 kg / cm ² , (II) linear expansion coefficient (ASTM D696, thickness 3 mm, length 45 mm,
23 to 80 ° C.) is 8 × 10 ⁻⁵ cm / cm / ° C. or less.

Further, the coated body of the soft resin bumper for automobiles according to the present invention is characterized in that a coating film of acrylic melamine resin-based paint is directly formed on the surface of the soft resin bumper.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The soft resin bumper for automobiles and the coated body thereof according to the present invention will be specifically described below.

First, each component of the propylene-based polymer composition constituting the bumper made of a soft resin for automobiles according to the present invention will be described. Propylene-based Polymer (a) The propylene-based polymer (a) used in the present invention is a propylene homopolymer or a copolymer of propylene and other α-olefin having a propylene content of 85 mol% or more. is there.

Examples of α-olefins copolymerizable with propylene include ethylene, butene-1, pentene-1, 2-methylbutene-1,3-methylbutene-1, hexene-1,3-methylpentene-1,4. -Methylpentene-1,3,3-dimethylbutene
-1, Heptene-1, Methylhexene-1, Dimethylpentene
-1, trimethylbutene-1, ethylpentene-1, octene
-1, methylpentene-1, dimethylhexene-1, trimethylpentene-1, ethylhexene-1, methylethylpentene-1, diethylbutene-1, propylpentene-1, decene
-1, methylnonene-1, dimethyloctene-1, trimethylheptene-1, ethyloctene-1, methylethylheptene
-1, diethylhexene-1, dodecene-1, and hexadodecene. These α-olefins may form a random copolymer with propylene, and
A block copolymer may be formed.

The propylene polymer (a) used in the present invention has a melt flow rate (MFR; ASTM D 1238,
230 ° C, load 2.16 kg) is 20 to 100 g / 10 minutes, preferably 30 to 80 g / 10 minutes, more preferably 40 to
Within the range of 70 g / 10 minutes. By using the propylene-based polymer having such MFR, good moldability can be ensured. The density of the propylene polymer (a) is usually 0.90 to 0.92 g / c.
Within the range of m ³ .

In the present invention, the propylene-based polymer (a) includes the propylene-based polymer (a) and ethylene / α-
It is used in an amount of 50 to 65 parts by weight, preferably 50 to 60 parts by weight, based on 100 parts by weight of the total amount of the olefin copolymer (b). When the propylene-based polymer (a) is used in the above amount, a composition which can provide a bumper having high rigidity and excellent impact resistance can be obtained.

[0016]Ethylene / α-olefin copolymer
(B) Ethylene / α-olefin copolymerization used in the present invention
Body (b) is ethylene and propylene, butene-1, penta
Copolymers with α-olefins such as amine-1, or these
And a non-conjugated diene.

Specific examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene, methylene norbornene and 5-ethylidene-2-norbornene.

Specific examples of the ethylene / α-olefin-based copolymer (b) include ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / propylene / butene-1 copolymer, Examples thereof include ethylene / propylene / non-conjugated diene copolymer, ethylene / butene-1 / non-conjugated diene copolymer, and ethylene / propylene / butene-1 / non-conjugated diene copolymer.

The ethylene / α-olefin copolymer (b) has an ethylene content of 30 to 98 mol%, preferably 40 to 97 mol%, and more preferably 70 to 97 mol%.

The ethylene / α-olefin copolymer (b) may be an amorphous rubber-like elastic body or a crystalline copolymer such as low-density linear polyethylene. May be. In the present invention, a rubber-like elastic ethylene / α-olefin copolymer (b) is usually used.
The ethylene / α-olefin-based copolymer (b) of this rubber-like elastic material has the effect of lowering the linear expansion coefficient when used in combination with low-density linear polyethylene.

Further, the melt flow rate (MFR; ASTM D 1) of the above ethylene / α-olefin copolymer (b).
238, 230 ℃, load 2.16kg) is 0.1-50g / 10
Min, preferably 0.1 to 30 g / 10 min, more preferably 0.1 to 20 g / 10 min. The iodine value (unsaturation) of this ethylene / α-olefin-based copolymer (b) is preferably 16 or less.

In the present invention, the ethylene / α-olefin copolymer (b) is added to 100 parts by weight of the total amount of the propylene polymer (a) and the ethylene / α-olefin copolymer (b). On the other hand, it is used in an amount of 50 to 35 parts by weight, preferably 50 to 40 parts by weight. When the ethylene / α-olefin-based copolymer (b) is used in the above amount, a composition which has high rigidity and can provide a bumper excellent in impact resistance can be obtained.

Talc (c) Talc (c) used in the present invention has an average particle size of 1.0.
Is about 2.5 μm. In the present invention, talc (c)
Is used in an amount of 1 to 10 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the total amount of the propylene-based polymer (a) and the ethylene / α-olefin-based copolymer (b). To be

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[0042]

[0043]

Polar group-containing propylene polymer (e) The polar group-containing propylene polymer (e) used in the present invention is a propylene polymer (e-1) having a carboxyl group or an acid anhydride group in the molecule. And an amino compound (e-2) are heated.

The propylene-based polymer (e-1) having a carboxyl group or an acid anhydride group in the molecule is a radical initiator containing a propylene-based polymer and an unsaturated compound having a carboxyl group or an acid anhydride group in the molecule. It can be obtained by carrying out a graft reaction by heating in the presence of

Specific examples of such unsaturated compounds include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, tetrahydrophthalic acid and methyltetrahydrophthalic acid. Α, β-unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride and tetrahydrophthalic anhydride; bicyclo [2.2.
1] An unsaturated carboxylic acid anhydride such as hept-2-ene-5,6-dicarboxylic acid anhydride can be mentioned. Among these,
Acrylic acid, maleic acid, itaconic acid, maleic anhydride and itaconic anhydride are preferred.

An organic peroxide is used as the above radical initiator. Specific examples of the organic peroxide include the organic peroxides exemplified above.

Such radical initiators can be used alone or in combination. The unsaturated compound having a carboxyl group or an acid anhydride group in the molecule is 0.01 to 50 parts by weight, preferably 0.1 to 40 parts by weight based on 100 parts by weight of the propylene-based polymer before graft modification.
Used in parts by weight.

The radical initiator is added in an amount of 0.01 to 100 parts by weight of the propylene polymer before graft modification.
It is used in an amount of from 10 to 10 parts by weight, preferably 0.05 to 8 parts by weight.

The above graft modification can be carried out by a known method. For example, there are the following methods. (I) A method in which the propylene-based polymer and an unsaturated compound having a carboxyl group or an acid anhydride group in the molecule are melt-kneaded by a kneading device such as an intensive mixer or an extruder in the presence of a radical initiator.

The above kneading is preferably performed in an atmosphere of an inert gas such as nitrogen. The kneading temperature is a temperature at which the half-life of the radical initiator used is 1 minute, usually 150.
To 280 ° C., preferably 170 to 240 ° C., and the kneading time is usually 30 seconds to 20 minutes, preferably 1 to 10 minutes. (Ii) A method in which an unsaturated compound having a carboxyl group or an acid anhydride group in the molecule and a radical initiator are added to a solution of the propylene-based polymer in an organic solvent and the mixture is heated.

The above heating is preferably performed in an atmosphere of an inert gas such as nitrogen. The heating temperature is a temperature at which the half-life of the radical initiator used is 1 minute, usually 100.
To 200 ° C., preferably 120 to 180 ° C., and the heating time is usually 0.5 to 10 hours, preferably 1 to 5 hours. The unsaturated compound having a carboxyl group or an acid anhydride group in the molecule and the radical initiator may be charged all at once when the propylene polymer is dissolved in an organic solvent, or the dissolved propylene polymer may be mixed with The saturated compound and the radical initiator may be separately added dropwise.

Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and xylene, cyclohexane,
Alicyclic hydrocarbons such as methylcyclohexane and chlorine hydrocarbons such as chlorobenzene and dichlorobenzene are used.

The propylene-based polymer (e-1) having a carboxyl group or acid anhydride group in the molecule produced by the above-mentioned method has a carboxyl group or acid anhydride group content of the propylene polymer (e-1). e-1) 0.01 to 30% by weight, preferably 0.05 to 100% by weight
It is 10% by weight.

The amino compound (e- used in the present invention
2) is a compound having at least one amino group in the molecule, specifically, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 5-amino-1. -Pentanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-
Examples thereof include amino alcohols such as 1,3-propanediol, N-aminoethylethanolamine and 2- (2-aminoethoxy) ethanol.

The polar group-containing propylene polymer (e) used in the present invention is, as described above, a propylene polymer (e- having a carboxyl group or an acid anhydride group in the molecule).
It is obtained by heating 1) and the amino compound (e-2).

Examples of this heating method include the following methods. (I) A method of melt-kneading the propylene polymer (e-1) and the amino compound (e-2). (II) A method in which the propylene polymer (e-1) and the amino compound (e-2) are dissolved in an organic solvent and heated.

The polar group-containing propylene polymer (e) produced by the above-mentioned method has an intrinsic viscosity (measured in decalin at 190 ° C.) of 1.0 dl / g or less, preferably 0.
15-0.8 dl / g, more preferably 0.2-0.
It is 5 dl / g.

In the present invention, the polar group-containing propylene polymer (e) is based on 100 parts by weight of the total amount of the propylene polymer (a) and the ethylene / α-olefin copolymer (b). 0.1 to 30 parts by weight, preferably 3 to 2
Used in an amount of 0 parts by weight. When the polar group-containing propylene polymer (e) is used in the above amount, a composition capable of providing a bumper having excellent impact resistance can be obtained.

Method for Producing Propylene-Based Polymer Composition In order to produce the propylene-based polymer composition used in the present invention, the above-mentioned components are added to a conventional olefin-based polymer so as to be within the above composition ratio range. Mixing may be carried out in a field by applying a mixing method which is practiced in the field. At this time, all the composition components may be mixed at the same time, or a part of the composition components may be mixed in advance to produce a so-called masterbatch, and the masterbatch and the remaining composition components may be mixed.

Other thermoplastic resins, softeners, fillers, and
Pigments, stabilizers, plasticizers, flame retardants, lubricants, antistatic agents,
An electrical property improver can be added if necessary.

The above kneading is preferably carried out in a non-open type apparatus, and is preferably carried out in an atmosphere of an inert gas such as nitrogen or carbon dioxide. The kneading temperature is usually 150
To 280 ° C, preferably 170 to 240 ° C, and the kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes.

As the kneading device, a mixing roll, an intensive mixer such as a Banbury mixer, a kneader, a single-screw or twin-screw extruder can be used.
A non-open device is desirable.

Propylene-based polymerization thus obtained
The body composition is usually formed into pellets.Injection molded body as bumper for automobile Injection molding machine using the above-mentioned propylene-based polymer composition
A molded product is obtained by(C) and
The mixing ratio of each component of (e) is within the above range.
The flexural modulus at 23 ° C, which is a requirement for clarity, is 4,0.
00-7,000 kg / cm² To be within the range of
is necessary.

When the molded body is used as a bumper for automobiles, if the flexural modulus of the molded body is within the above range, the molded body is taken out of the molding die and the productivity such as mounting to the vehicle body is improved. There is no problem, and the performance in recoverability during deformation and shock absorption during impact does not deteriorate.

In addition, the blending ratio of each of the components (a) to (c) and (e) is such that not only the flexural modulus is within the above range, but also the linear expansion coefficient (ASTM D) which is a requirement of the present invention. 69
6, thickness 3 mm, length 45 mm, 23-80 ° C) is 8 ×
It is necessary to select it to be 10 ⁻⁵ cm / cm / ° C. or less. When the molded product is used as a bumper for automobiles, if the linear expansion coefficient of the molded product is within the above range, the dimensional change amount becomes large with respect to temperature change, and the bumper mounted on the vehicle body swells or dents. There is no problem in appearance.

Further, the soft resin bumper for automobiles of the present invention preferably has an average thickness of 1.5 to 6.0 mm. When the average thickness of the bumper is in the above range, the shape retainability is good, the linear expansion coefficient of the molded product is small, the weight of the molded product is moderate, and the vehicle body is well balanced.

Coated Body of Automotive Soft Resin Bumper The coated body of automotive soft resin bumper of the present invention is
A coating film of acrylic melamine resin-based paint is directly formed on the surface of the soft resin bumper for automobiles obtained as described above.

As the acrylic melamine resin-based coating material, a conventionally known acrylic melamine resin-based coating material used for coating automobile bumpers can be used.
Further, as a coating method, a coating method which has been conventionally used for coating automobile bumpers can be adopted.

[0070]

The soft resin bumper for an automobile according to the present invention comprises a specific propylene polymer (a), a specific ethylene / α-olefin copolymer (b) and a specific talc (c). And an essential component, a specific polar group-containing propylene polymer (e) as a constituent component, and a propylene-based polymer composition containing these components in a specific ratio, and a specific flexural modulus. Since it has a specific coefficient of linear expansion, it has excellent appearance (flow marks, welds, etc.) and dimensional stability, as well as a good balance between low temperature impact resistance and flexibility, and excellent paintability.

Further, the coated body of the bumper made of the soft resin for automobiles according to the present invention is excellent in the adhesiveness of the coating film because the coating film of the acrylic melamine resin-based paint is directly formed on the surface of the bumper. .

The present invention will be described below with reference to examples.
The invention is not limited to these examples.

[0073]

[Reference Example 1] [Production of a polymer (PBD) of a conjugated diene containing a hydroxyl group at the terminal of the molecular chain] In an autoclave having a capacity of 500 ml
1,3-butadiene 100g, isopropyl alcohol 70
g, 10 g of 60% hydrogen peroxide solution were charged, and the mixture was heated at 90 ° C. for 5 hours in a nitrogen atmosphere. Then, after cooling the autoclave, unreacted 1,3-butadiene was removed, and the produced butadiene polymer was taken out and dried.

The butadiene polymer (hereinafter abbreviated as PBD) obtained as described above is a Vapor Osmometer.
Has a molecular weight of 3,360 and a hydroxyl value of 48.
It was mgKOH / g. [Production of Hydrogenated Product (HPBD) of Polymer of Conjugated Diene Containing Hydroxyl Group at End of Molecular Chain] 50 g of PBD obtained by the above method for producing polymer and 5 g of carbon-supported ruthenium catalyst (5%) were prepared in a volume of 200 ml. Was charged into the autoclave, the air in the system was replaced with nitrogen gas, and then hydrogen gas was fed until the gas pressure reached 50 kg / cm ² . Then, the autoclave is heated to 100 ° C. and the total pressure is increased to 5
Hydrogen gas was supplied so as to be maintained at 0 kg / cm ² , and hydrogenation reaction was carried out for 8 hours. After the reaction is completed, hydrogen is removed,
After filtering off the catalyst, the hydrogenated product formed was precipitated in methanol and dried.

The hydrogenated product (hereinafter abbreviated as HPBD) obtained as described above has an iodine value of 1.2,
The hydroxyl value was 45 mg KOH / g.

[0076]

[Reference Example 2] [Production of modified propylene polymer (MPP)] 50 g of propylene homopolymer (MFR: 10 g / 10 minutes) and p-
500 ml of xylene was placed in a glass separable flask having a volume of 1 liter and heated to 130 ° C. to dissolve a propylene homopolymer in p-xylene. Then, 5 g of maleic anhydride (hereinafter abbreviated as MAH) and 0.5 g of dicumyl peroxide were added dropwise to this solution over 4 hours,
Furthermore, this solution was heated for 2 hours. Next, this solution was allowed to cool and then poured into acetone to obtain a propylene homopolymer graft-modified with MAH (hereinafter abbreviated as MPP).

The amount of MAH grafted in the MPP obtained as described above was 3.0% by weight as measured by infrared absorption analysis. In addition, this MPP 19
The intrinsic viscosity [η] measured in decalin at 0 ° C is 0.3.
It was 8 dl / g.

[0078]

[Reference Example 3] [Production of polar group-containing propylene polymer (APP)] MP
50 g of P, 3 g of 2-aminoethanol and 500 ml of p-xylene were placed in a glass separable flask having a volume of 1 liter and heated for 3 hours. Next, the contents of this flask were allowed to cool and then put into acetone to obtain a polar group-containing propylene homopolymer (hereinafter abbreviated as APP).

190 of APP obtained as described above
The intrinsic viscosity was 0.35 dl / g as measured in decalin at 0 ° C.

[0080]

[Examples 1, 2, Reference Examples 4, 5 and Comparative Examples 1-5]
[Production of Propylene-Based Polymer Composition] The components shown in Table 1, 0.2 parts by weight of Irganox 1010 [trade name; manufactured by Ciba Gaggy] as a heat resistance stabilizer, and Armoslip [as a mold releasing agent]. 0.2 parts by weight of a trade name; manufactured by Lion Corporation] was melt-kneaded at a temperature of 200 ° C. by a twin-screw extruder to produce a composition.

Among the components in Table 1, the components other than the above are as follows. H-PP: Propylene homopolymer MFR 50 g / 10 min B-PP: Propylene / ethylene block copolymer MFR 43 g / 10 min, propylene content 90 mol% LLDPE: Ethylene-4-methyl-1-pentene copolymer MFR 28 g / 10 min, ethylene content 97 mol% EPR-1: ethylene / propylene copolymer MFR 0.4 g / 10 min, ethylene content 81 mol% EPR-2: ethylene / propylene copolymer MFR 12 g / 10 min, ethylene Content 86 mol% PER: ethylene / propylene copolymer MFR 0.5 g / 10 min, ethylene content 38 mol% talc: average particle size 1.6 μm Then, the composition and the molded product produced as described above are as follows. Was evaluated.

The results are shown in Table 1. [Melt flow rate (MFR) of composition] JIS-K
According to 7210. (Measurement conditions: 230 ° C, 2.16 kg load) [Painting evaluation] 70 mm was obtained by injection molding the composition produced as described above with an injection molding machine with a mold clamping pressure of 100 tons.
An injection molded body of × 150 mm × 3 mm was obtained.

Then, after the surface of this injection-molded article was subjected to isopropyl alcohol (IPA) wipe pretreatment,
It was dried using an air gun. Then, an acrylic melamine resin-based paint [B236 of Nippon Paint Co., Ltd.] was applied to the surface of the injection-molded article with an air spray gun,
Baking was carried out at 120 ° C. for 30 minutes and left for 48 hours or more to carry out the following cross-cut peeling test. The above coating was applied by spraying so that the thickness of the coating film was about 30 microns.

Adhesion test of coating film ( cross-cut peeling test) Draw 11 parallel and 11 horizontal and vertical lines with a cutter at intervals of 2 mm on the coated surface of the injection-molded article produced in the above manner to obtain a sufficient depth of the coating. A cut (until the compact was reached) was made. Then, after the cellophane adhesive tape (JIS Z 1522) was pressure-bonded to the 100 eyes thus completed, the tape was peeled off and the number of grids attached was recorded. [Evaluation of Mechanical Strength Characteristics and Dimensional Stability] (Flexural Modulus) Based on JIS K7203. (Measurement temperature: 23 ° C.) (Linear expansion coefficient) According to ASTM D696.

Regarding the following evaluations, the composition produced as described above was injection-molded by a large-sized injection molding machine with a mold clamping pressure of 2000 tons to obtain an average wall thickness of 3.5 mm.
The evaluation was performed using an automobile bumper-shaped molded body as shown in FIG. [Evaluation of appearance of molded product] A large injection molded product having a bumper structure, a flow pattern (flow mark) generated in a resin flow process, and a line (weld) at the time of joining of resins.
When the presence was visually confirmed, it was marked with X, and when it could not be confirmed, it was marked with ◯. [Evaluation of low-temperature impact resistance and deformation recovery property] An impact test was conducted under the following conditions based on US Motor Vehicle Safety Standard (F-MVSS) Part 581.

Measuring instrument: Pendulum type impact tester Temperature: -30 ° C Speed: 8 km / hour (5 miles / hour) Load: 1.6 tons In this evaluation of low temperature impact resistance, the molded body was cracked, When a crack or the like was generated, it was marked with X, and when it was not cracked, it was marked with ◯.

Further, in the evaluation of the deformation recovery property, when the amount of deformation after leaving the test piece after the impact test for 24 hours at 23 ° C. is less than 10 mm with respect to the original shape, it is ○, 10 mm.
The above cases were marked with x. [Evaluation of thermal deformability after mounting on vehicle body] An automobile bumper-shaped injection-molded body was fixed with a jig at four points on each of the upper and lower surfaces, for a total of eight points, and allowed to stand in an atmosphere of 80 ° C for 3 hours. The presence or absence of deformation was visually observed. In the evaluation of the heat deformability, when the deformation was recognized, it was marked with X, and when the deformation was hardly recognized, it was marked with ◯. [Evaluation of injection moldability] When a molded product is injection-molded under the following molding conditions and there is no problem with the releasability of the molded product, ○,
When the molded product was defective in demolding and caused a problem in releasability, it was marked with x.

Molding conditions Injection molding model: Clamping pressure 2000 tons Large injection molding machine Set resin temperature: 230 ℃ Set mold temperature: 23 ℃ Cooling time: 40 seconds

[0089]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 23:26) (72) Inventor Kosuke Kaku 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Invention Masahiro Terada 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa 2 Nissan Motor Co., Ltd. (56) Reference JP-A-6-157838 (JP, A) JP-A-6-128432 (JP, A) JP-A 5-170987 (JP, A) JP 5-295227 (JP, A) JP 4-7112 (JP, A) JP 7-315150 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13/08 B60R 19/03

Claims (2)

(57) [Claims] 1. (a) Melt flow rate (ASTM D 1238, 230 ° C., load 2.) with propylene content of 85 mol% or more.
16 kg) and 50 to 65 parts by weight of a propylene-based polymer of 20 to 100 g / 10 minutes, and (b) ethylene / α having an ethylene content of 30 to 98 mol%.
-Olefin copolymer 50 to 35 parts by weight [the total amount of the components (a) and (b) is 100 parts by weight], and (c) talc 1 to 10 having an average particle size of 1.0 to 2.5 μm.
And (e) a propylene-based polymer (e-1) having a carboxyl group or an acid anhydride group in the molecule, and an amino compound (e-).
2) A propylene polymer having 0.1 to 30 parts by weight of a polar group-containing propylene polymer having an intrinsic viscosity of 1.0 dl / g or less measured in decalin at 190 ° C. And (I) the flexural modulus measured at 23 ° C. is 4,000 to 7,
000 kg / cm ² , (II) linear expansion coefficient (ASTM D696, thickness 3 mm, length 45 mm,
23-80 ° C.) is 8 × 10 ⁻⁵ cm / cm / ° C. or less, a soft resin bumper for automobiles. 2. A coated body of a soft resin bumper for an automobile, wherein a coating film of acrylic melamine resin-based paint is directly formed on the surface of the soft resin bumper.