JPH0639556B2 - Propylene homopolymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a propylene homopolymer composition having excellent adhesion to polyurethane without using a primer. More in detail to (A) (1) propylene homopolymer
(2) at least one unsaturated bond in the molecule, and a hydroxyl group-containing organic compound and (3) a modified propylene homopolymer obtained by treating an organic peroxide, (B) crystallinity Ethylene-propylene block copolymer, (C) Mooney viscosity is 20 ~ 100 amorphous ethylene-propylene copolymer and (D) relates to a propylene homopolymer composition comprising an inorganic filler, rigidity, low temperature It is an object of the present invention to provide a propylene homopolymer composition which has not only excellent mechanical properties such as impact resistance but also good adhesion to polyurethane without the use of a primer.

As is well known, propylene-based polymers (propylene homopolymers and propylene copolymers) have not only excellent moldability but also mechanical properties, heat resistance, solvent resistance, oil resistance and chemical resistance. Because of such good characteristics, it is widely industrially manufactured and used in various fields as parts for automobiles, electric appliances, electronic devices and daily necessities. However, since it does not have a polar group in the molecule (so-called non-polar), the adhesion to polyurethane is not good, which causes various problems. With respect to this, a widely used automobile bumper will be described as an example.

Conventionally, bumpers made of metal or polyurethane have been widely used. In recent years, a propylene-based polymer (propylene homopolymer, ethylene-propylene random or block copolymer) containing propylene as a main component or a composition containing a propylene-based polymer as a main component, aiming at weight reduction and cost reduction of automobiles. Bumpers made from objects are widely used. In many cases, this bumper is used as it is without being painted, because the surface of the molded product is pre-textured before it is mounted on the vehicle. However, in order to make the bumper even more fresh and luxurious, it is often the case that polyurethane is applied to the bumper and the bumper is mounted on the vehicle.

However, as mentioned above, propylene-based polymers are chemically extremely inactive polymeric substances because they do not have polar groups in the molecule. The reality is that a primer that can adhere to a propylene-based polymer is undercoated and a polyurethane coating is applied as an overcoat. That is, the steps of primer undercoating → baking → polyurethane coating → baking (2 coat 2 bake or 3 coat 2 bake) must be performed, and this coating process requires a long time (usually about 1 hour 30 minutes). For this reason, it takes a long coating cycle to manufacture a bumper coated with this polyurethane, which not only makes mass production difficult but also increases the cost.

In manufacturing other automobile parts, electric appliance parts, electronic appliance parts, etc., when a propylene-based polymer is used and polyurethane is applied, the application method is different, but the same problem as described above occurs.

To solve these problems, some of the present inventors have modified propylene-based polymer obtained by treating a propylene copolymer with an organic compound containing a hydroxyl group and an organic peroxide, crystalline ethylene. A propylene-based polymer composition comprising a propylene block copolymer, an amorphous ethylene-propylene copolymer and an inorganic filler has been previously proposed (Japanese Patent Application No. 60-113279). This propylene-based polymer composition has not only excellent adhesion to polyurethane, but also good flexural modulus (rigidity) and low-temperature impact resistance, and excellent processability and moldability. However, the gloss of the molded product (for example, bumper) of the composition is not sufficient as compared with the conventional propylene-based polymer composition and the appearance is poor. This tendency becomes more remarkable when a pretreatment for coating (for example, steam treatment of 1,1,1-trichloroethane) is performed. In addition, if you try to increase the blending ratio of the modified propylene-based polymer used to further improve the adhesion to polyurethane, there will be problems such as the occurrence of flow marks with a decrease in gloss, and molding from a practical standpoint. There is a problem that use may be restricted unless it is a matte type molded product that does not require the luster of the product, or a molded product with a full surface coating finish.

Problems to be Solved by the Invention From the above, the present invention does not have these problems (deficiencies), that is, does the propylene-based polymer retain various mechanical properties (for example, impact strength and rigidity)? Another object of the present invention is to obtain a propylene-based polymer composition which is not only improved but also has excellent moldability and excellent appearance, and has excellent adhesion to polyurethane without the use of a primer.

Means and Actions for Solving the Problems According to the present invention, the above-mentioned problems are (A) (1) 100 parts by weight of a propylene homopolymer (2) `` at least one unsaturated bond is present in the molecule. And a hydroxyl group-containing organic compound "(hereinafter referred to as" hydroxyl compound ") 0.1 to 50 parts by weight and (3) 0.01 to 20 parts by weight of an organic peroxide. Combined, (B) Melt flow index (in accordance with JIS K-7210,
Measured at a temperature of 230 ° C and a load of 2.16 kg.
(FR)) of 2.0 to 100 g / 10 minutes and an ethylene content of 2.0 to 15% by weight, (C) Mooney viscosity [ML _{1 + 4} , ( 100 ° C.)] is from 20 to 100 and the content of propylene is from 20 to 50% by weight], and a composition comprising an amorphous ethylene-propylene copolymer and (D) an inorganic filler. The composition ratio of the inorganic filler is 2.0 to 25% by weight, and the total amount of the modified propylene homopolymer, the crystalline ethylene-propylene block copolymer and the amorphous ethylene-propylene copolymer is 10
The ratio of the hydroxyl compound to 0 parts by weight is 0.01 to 10.0 parts by weight as a monomer unit, and the composition of the modified propylene homopolymer in the total amount of the modified propylene homopolymer and the crystalline ethylene-propylene block copolymer. The ratio is 5 to 90% by weight, the composition ratio of the modified propylene homopolymer in the composition is at least 3.0% by weight, and the composition ratio of the amorphous ethylene-propylene copolymer is 25 to 50% by weight. It can be solved by some propylene homopolymer compositions. Hereinafter, the present invention will be specifically described.

(A) Modified Propylene Homopolymer The modified propylene homopolymer of the present invention is obtained by treating a propylene homopolymer described below with a hydroxyl compound and an organic peroxy acid compound. It is described in detail in the specification of JP-A-58-154732.

(1) Propylene Homopolymer The MFR of this propylene homopolymer is usually 0.01 to 100 g / 10 from the viewpoint of moldability and mechanical properties of the resulting composition.
Minutes, preferably 0.01 to 50 g / 10 minutes, especially 0.02 to 20
It is preferably g / 10 min.

(2) Hydroxyl Compound The hydroxyl compound is a compound having at least one unsaturated bond (double bond or triple bond) and containing a hydroxyl group. Typical examples thereof include an alcohol having a double bond, an alcohol having a triple bond, an ester of a monovalent or divalent unsaturated carboxylic acid and an unsubstituted dihydric alcohol, an unsaturated carboxylic acid and an unsubstituted trivalent alcohol. Examples thereof include esters with polyhydric alcohols, esters with unsubstituted tetrahydric alcohols, and esters with unsubstituted pentavalent or higher alcohols.

(3) Organic peroxide Furthermore, the organic peroxide is generally used as an initiator in radical polymerization and a cross-linking agent for the polymer, and one having a half-life of 1 minute or more of 100 ° C. or more is preferable. A temperature of 130 ° C or higher is suitable. Above temperature is 100
If the temperature is lower than 0 ° C, not only is it difficult to handle, but also the effect of use is not so noticeable, which is not desirable.

(4) Mixing ratio In producing the mixture of the present invention, the mixing ratio of the hydroxyl compound to 100 parts by weight of the propylene homopolymer is 0.1 to 50 parts by weight, preferably 0.2 to 30 parts by weight, particularly 0.3 to 20 parts by weight. Weight parts are preferred. If the mixing ratio of the hydroxyl compound to the propylene homopolymer of 100 parts by weight is 0.1 parts by weight or less, the effect of improving the adhesiveness is insufficient. On the other hand, even if it is used in an amount of 50 parts by weight or more, the effect of improving the adhesion depending on the amount used is not recognized, and rather the original properties of the propylene homopolymer are impaired, which is not preferable.

Further, the mixing ratio of the organic peroxide to 100 parts by weight of propylene homopolymer is 0.01 to 20 parts by weight, 0.05 to 10 parts by weight.
Weight part is desirable, and 0.1 to 7 weight part is particularly preferable. When the mixing ratio of the organic peroxide with respect to 100 parts by weight of the propylene homopolymer is 0.01 parts by weight or less, not only the effect of improving the adhesiveness is low, but also the durability of the adhesive strength of the mixture is reduced. On the other hand, when the amount is 20 parts by weight or more, the excellent mechanical properties of the polymer in the future are deteriorated, and therefore, it is not desirable in any case.

(5) Method for producing modified propylene homopolymer In order to produce the modified propylene homopolymer of the present invention, the above propylene homopolymer, hydroxyl compound and organic peroxide are treated at the above mixing ratio (heating). Can be manufactured. At this time, the propylene homopolymer, the hydroxyl compound and the organic peroxide may be treated while being mixed, but they may be mixed in advance by dry blending, or at a relatively low temperature (a temperature at which the hydroxyl compound does not react). Knead with
It is obtained by heating the resulting mixture as described below.

If the treatment is carried out at a high temperature, the propylene homopolymer may deteriorate. However, it must be carried out at a temperature at which the organic peroxide used for graft-polymerizing the propylene homopolymer used and the hydroxyl-based compound decomposes. From the above, this treatment is generally performed at 160% depending on the type of organic peroxide used.
It is carried out at -300 ° C (preferably 170-280 ° C).

The general formulas and typical examples of the hydroxyl compounds and organic peroxides, the mixing method and the treating method are described in detail in JP-A-58-154732.

(B) Crystalline ethylene-propylene block copolymer Also, the crystalline ethylene-propylene block copolymer used in the present invention has an MFR of 2.0 to 100 g / 10 minutes, preferably 3.0 to 80 g / 10 minutes, and particularly preferably , 5.0-50g
/ 10 minutes is preferred. If a crystalline ethylene-propylene block copolymer having an MFR of less than 2.0 g / 10 min is used, the flexural modulus of the resulting composition will be low, and this decrease in flexural modulus will be caused by other synthetic resins or fillers. To compensate for this, the balance between flexural modulus and impact strength becomes poor. On the other hand, if a crystalline ethylene-propylene block copolymer exceeding 100 g / 10 min is used, not only it becomes difficult to uniformly disperse it with other composition components during kneading, but also the impact of the obtained composition at low temperature Strength is reduced.

Further, the ethylene content of the block copolymer is 2.0
15 to 15% by weight, preferably 3.0 to 15% by weight, especially 3.0
-12 wt% is preferred. When the ethylene content is less than 3.0% by weight, the resulting composition has poor impact resistance at low temperatures. On the other hand, when it exceeds 15% by weight, mechanical properties such as rigidity (flexural modulus) and tensile strength of the obtained composition are low.

The propylene homopolymer and the crystalline ethylene-propylene block copolymer used for producing the modified propylene homopolymer are both industrially produced and used in various fields, It is well known about their manufacturing method and various physical properties.

(C) Amorphous ethylene-propylene copolymer Further, the Mooney viscosity of the amorphous ethylene-propylene copolymer used in the present invention [ML _{1 + 4} , (100
C)) is 20-100, preferably 20-80, especially 3
0 to 75 is preferable. If an amorphous ethylene-propylene copolymer with a Mooney viscosity of less than 20 is used, the moldability will improve, but layer peeling may occur during gate cutting of the molded product, causing troubles. There is. On the other hand, if more than 100 is used, not only it becomes difficult to uniformly disperse with other composition components during kneading, but even if a uniform composition is obtained, a flow mark on the surface of the molded product, Weld lines are not noticeable,
A molded product with a good appearance cannot be obtained. Further, the propylene content of this copolymer is generally 20 to 50% by weight, preferably 25 to 45% by weight, and more preferably 25 to 40% by weight. This amorphous ethylene-propylene copolymer has rubber-like properties, is industrially produced, and is used in various fields, and its production method is also widely known.

(D) Inorganic Filler The inorganic filler used in the present invention is generally widely used in the fields of synthetic resins and rubber. As these inorganic fillers, inorganic compounds that do not react with oxygen and water and that do not decompose during kneading and molding are preferably used. Examples of the inorganic filler include metals such as aluminum, copper, iron, lead and nickel, oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony and titanium, and water thereof. Compounds such as hydrates (hydroxides), sulfates, carbonates and silicates, double salts thereof and mixtures thereof are roughly classified. Typical examples of the inorganic filler are described in Japanese Patent Application No. 59-8535. Of these inorganic fillers, powdery ones having a diameter of 30 μm or less (preferably 10 μm or less) are preferable. For fibrous materials, the diameter is 1 to 500 microns (preferably 1 to 300 microns),
The length is preferably 0.1 to 6 mm (preferably 0.1 to 5 mm). Further, it is preferable that the flat plate has a diameter of 30 microns or less (preferably 10 microns or less). Of these inorganic fillers, flat plate-shaped (flake-shaped) and powdered ones are particularly preferable. Suitable inorganic fillers include ralc, mica, silica, glass fibers, graphite and the like.

(E) Composition Ratio The composition ratio of the inorganic filler in the composition obtained in the present invention is 2.0 to 25% by weight, preferably 2.5 to 25% by weight, and particularly preferably 3.0 to 20% by weight. When the composition ratio of the inorganic filler in this composition is less than 2.0% by weight,
The flexural modulus of the resulting composition is not improved. On the other hand, 25
When the content is more than 10% by weight, not only the composition has poor impact resistance at low temperature, but also silver may be generated during molding. There is a means of pre-drying the composition in order to prevent the generation of this silver, but this is not a good idea in mass production of large molded articles such as bumpers.

The composition ratio of the modified propylene homopolymer in the total amount (total) of the modified propylene homopolymer and the crystalline ethylene-propylene block copolymer is 5 to 90% by weight, and 10 to 80% by weight is Desirably, especially 20 to 60% by weight is suitable. When the composition ratio of the modified propylene homopolymer in the total amount of the modified propylene homopolymer and the crystalline ethylene-propylene block copolymer is less than 5% by weight, the adhesion between the composition and polyurethane is poor. On the other hand, if it exceeds 90% by weight, the impact resistance at low temperature becomes insufficient.

Further, the composition ratio of the modified propylene homopolymer in the composition is at least 5% by weight, preferably 5 to 20% by weight, particularly preferably 5 to 15% by weight. The composition ratio of the modified propylene homopolymer in the composition is 5% by weight.
If it is less than the above range, the adhesion between the composition and polyurethane is not good.

The composition ratio of the amorphous ethylene-propylene copolymer in the composition is 15 to 40% by weight, and 15 to 35% by weight.
Is preferable, and most preferably 20 to 35% by weight. When the composition ratio of the amorphous ethylene-propylene copolymer in the composition is less than 15% by weight, the impact resistance at low temperature of the composition is not good. On the other hand, when it exceeds 40% by weight, the impact resistance at low temperature is excellent, but the flexural modulus (rigidity) is low, which is not good in terms of balance.

Furthermore, modified propylene homopolymer, crystalline ethylene-
The ratio of the organic compound containing a hydroxyl group to the total amount 100 parts by weight of the propylene block copolymer and the amorphous ethylene-propylene copolymer is 0.01 to 10.0 parts by weight as a monomer unit, preferably 0.1 to 10.0 parts by weight, Especially, 0.2 to 5.0 parts by weight is preferable. If the proportion of the organic compound containing a hydroxyl group is less than 0.01 parts by weight per 100 parts by weight of the total amount of these polymers, the adhesiveness between the resulting composition and polyurethane will be insufficient. Further, even if the amount exceeds 10.0 parts by weight, the adhesion cannot be further improved.

(F) Production of composition, molding method, etc. To produce the composition of the present invention, the modified propylene homopolymer, crystalline ethylene-propylene block copolymer, amorphous ethylene-propylene copolymer and inorganic filler The agent may be mixed so as to be uniform by applying a mixing method which is generally used in the field of olefin polymers so that the content of the agent falls within the range of the above composition ratio. 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. At this time, a stabilizer for heat, oxygen or ultraviolet rays, which is generally blended (added) to the olefin polymer,
Additives such as a metal deterioration inhibitor, a plasticizer, a flame retardant, a lubricant, a filler, a colorant, an antistatic agent and an electrical property improver are added to the composition within a range that does not impair the physical properties of the composition. You may mix | blend according to the intended purpose.

The composition thus obtained is usually molded into pellets, and is manufactured into a desired molded product by a molding method such as an injection molding method or an extrusion molding method that is generally performed in the field of each thermoplastic resin.

Even when melt-kneading when producing the composition,
Even in the case of molding, the temperature is higher than the melting point of the polymer used, but is a temperature at which thermal decomposition does not occur. For these reasons, it is generally carried out at 180 to 300 ° C (preferably 190 to 250 ° C).

Generally, olefin polymers have extremely poor adhesion to polyurethane, so when applying a polyurethane paint to a molded product of an olefin polymer or a composition thereof, a primer must be applied and dried in advance to apply the polyurethane paint. I have to. However, since the propylene homopolymer composition of the present invention has excellent adhesion with polyurethane, even if the primer is not applied to the surface of the molded product,
Polyurethane can be applied directly to the surface of the molded product (adhesion is further improved by using a primer).

The flexural modulus is 9,000 kg / cm ² or more, and the Izod impact strength (notched) at -30 ° C is 8 kgcm / cm.
Is. Furthermore, the melt flow index is 5g / 10
More than a minute.

Examples and Comparative Examples Hereinafter, the present invention will be described in more detail with reference to Examples.

In Examples and Comparative Examples, the flexural modulus is ASTM
Measured according to D790, Izod impact strength is ASTM
It was measured according to D256, and the gloss was measured according to JIS Z8741. In addition, the coating film adhesion strength was determined by placing a flat plate test piece (thickness 2 mm, 130 × 130 mm) in steam of 1,1,1-trichloroethane for 30 seconds and drying it sufficiently, and then using a high urethane paint (Nippon Pee Chemical Co. Ltd.). (Manufactured, product name R257, solid) was applied so as to have a dry thickness of 20 to 30 microns. After standing for about 15 minutes, a urethane paint (trade name, R266, Wacker Top, manufactured by Nippon Py Chemical Co., Ltd.) was applied so that the dry thickness would be 30 to 40 microns, and dried at 90 ° C for 30 minutes. Then, at room temperature (temperature 23 ℃, humidity
65%) and allowed to stand for 48 hours. The obtained coated product (test piece) is cut into a width of 10 mm, a part (about 10 mm) of the coating film is forcibly peeled from the resin portion of the test piece, and the remaining adhesion portion is used by a tensile tester. It was obtained by pulling in a reverse direction (180 degrees) to the coating film at a speed of 50 mm / min and measuring the peel strength. Furthermore, the same as the above except that a polyurethane paint (Nippon Pea Chemicals Co., Ltd., trade name R255, metallic red) was used instead of the high urethane paint used for measuring the coating film adhesion strength in the first-eye test. Was applied and dried. 1 on the coating surface of the obtained test piece
100 eyes were diced at mm intervals, and cellophane tape was completely adhered to the eyes by finger pressure. This cellophane tape was rapidly peeled off at an angle of 45 degrees. This operation was repeated twice to determine the percentage of the leftover coating film. The tensile test was performed according to JIS K-6301. Furthermore, the gasoline resistance was examined by immersing the test at room temperature (20 ° C.) for 24 hours and then observing the change state of the test piece.

Incidentally, modified propylene homopolymer used in Examples and Comparative Examples, modified propylene copolymer, ethylene-propylene block copolymer, amorphous ethylene-propylene copolymer rubber, inorganic filler, physical properties of other composition components,
The manufacturing method and the like are shown below.

[(A) modified propylene homopolymer]

As a modified propylene homopolymer, 4.0 parts by weight of 2-per 100 parts by weight of propylene homopolymer having an MFR of 0.5 g / 10 min.
Hydroxyethyl acrylate and 0.4 parts by weight of 2.2 '
-Bis (tertiary-butylperoxyisopropyl) benzene was previously dry blended for 5 minutes using a Henschel mixer. Pellets were produced by kneading the obtained mixture with an extruder with a vent (diameter 40 mm, cylinder temperature 160 to 200 ° C) [hereinafter referred to as "modified PP
(1) ”is used.

[(B) modified propylene copolymer]

For comparison, MFR was used as the modified propylene copolymer.
0.05 g / 10 min of ethylene-propylene block copolymer (ethylene content 8.0% by weight) 4.0 parts by weight of 2-hydroxyethyl acrylate and 1.0 parts by weight of 2.2'-bis (tertiary-butyl) Peroxyisopropyl) benzene was previously dry blended for 5 minutes using a Henschel mixer. The obtained mixture was kneaded using an extruder with a vent (diameter 40 mm, cylinder temperature 160 to 200 ° C.) to produce pellets [hereinafter referred to as “modified PP (2)”].

[(C) ethylene-propylene block copolymer]

As an ethylene-propylene block copolymer, MFR is 3
0 g / 10 min ethylene-propylene block copolymer [ethylene content 7.5% by weight, hereinafter referred to as "PP (A)"], MFR 28 g / 10 min ethylene-propylene block copolymer [ethylene content Amount of 10.1% by weight, hereinafter "PP
(B) ”], an ethylene-propylene block copolymer having an MFR of 15 g / 10 min [ethylene content 8.8% by weight,
Hereinafter referred to as "PP (C)", an ethylene-propylene block copolymer having an MFR of 12 g / 10 min [ethylene content 6.0
% By weight, hereinafter referred to as "PP (D)".

[(D) Amorphous ethylene-propylene copolymer]

As an amorphous ethylene-propylene copolymer, an amorphous ethylene-propylene copolymer having a Mooney viscosity [ML _{1 + 4} , (100 ° C)] of 35 (propylene content 27% by weight, hereinafter referred to as "EPR") It was used.

((E) Inorganic filler)

As the inorganic filler, talc having an average particle size of 2.0 μm, calcium carbonate having an average particle size of 2.0 μm (hereinafter referred to as “CaCO ₃ ”), and kraftite having an average particle size of 7 μm were used.

Examples 1 to 9 and Comparative Examples 1 to 47 Modified propylene homopolymers, modified propylene copolymers, ethylene-propylene block copolymers (as PP-based resins) whose blending amounts are shown in Table 1, Amorphous ethylene-propylene copolymer and talc (as an inorganic filler) were mixed for 5 minutes using a spar mixer.
Pellets (composition) were produced while kneading each of the obtained mixtures with a vented twin-screw extruder (cylinder temperature 180 to 200 ° C., diameter 30 mm). A flat plate (thickness: 2 mm, 130 × 130 mm), a bending elastic modulus measuring sample, and an Izod impact strength measuring sample were manufactured from each pellet using an injection molding machine of 5 ounces. Each of the obtained test pieces was subjected to coating film adhesion strength, Izod impact strength (measurement temperature −30 ° C., −40 ° C.), flexural modulus measurement and gloss, as well as a fair eye test and a gasoline resistance test. . The results are shown in Table 2.

In the gasoline resistance test, all the samples of Examples and Comparative Examples were carried out, but no abnormalities such as surface, peeling, swelling, wrinkles, etc. could be recognized in any of the test pieces.

From the results of the above Examples and Comparative Examples, the propylene homopolymer composition obtained by the present invention is
Not only the characteristics of the composition introduced in No. 279, namely mechanical strength (flexural modulus, impact resistance at low temperature, etc.) are excellent, but also processability is good, and the adhesion to polyurethane and gasoline resistance are good. It also has excellent properties, and it is obvious that the molded product has excellent surface appearance (gloss) properties while satisfying these requirements.

Effects of the Invention The propylene homopolymer composition obtained by the present invention exhibits the following effects as compared with the composition introduced in the above-mentioned Japanese Patent Application No. 60-113279.

(1) Workability and moldability are equal or higher.

(2) The appearance (gloss) of the molded product is excellent.

This means that the use of the composition is not limited to full-finished finished products, but it is also a great effect in that it expands the restrictions on the use of partially-finished finished products such as bumpers of polypropylene single composition currently being used. (Feature).

The propylene homopolymer composition of the present invention can be used in various fields in order to exert the above effects. Typical examples are automotive parts such as bumpers, bumper corners and engine undercovers.

Claims (4)

[Claims] (1) 100 parts by weight of a propylene homopolymer (2) 0.1 to 50 parts by weight of an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group, and (3) organic Modified propylene homopolymer obtained by treating 0.01 to 20 parts by weight of peroxide, 2. A melt flow index of 2.0 to 100 g /
A crystalline ethylene-propylene block copolymer having a content of ethylene of 2.0 to 15% by weight for 10 minutes, 3. The Mooney viscosity [ML _{1 + 4} , (100 ° C.)] is 20.
~ 100 and propylene content 20 ~ 50% by weight
And an amorphous ethylene-propylene copolymer which is 4. A composition comprising an inorganic filler, wherein the composition ratio of the inorganic filler in the composition is 2.0 to 25% by weight, and the modified propylene homopolymer, crystalline ethylene-propylene block copolymer. And the total amount of amorphous ethylene-propylene copolymer 10
The ratio of the organic compound containing a hydroxyl group to 0 parts by weight is 0.01 to 10.0 parts by weight as a monomer unit,
Further, the composition ratio of the modified propylene homopolymer in the total amount of the modified propylene homopolymer and the crystalline ethylene-propylene block copolymer is 5 to 90% by weight, and the modified propylene homopolymer in the composition accounts for A propylene homopolymer composition in which the composition ratio is at least 3.0% by weight and the composition ratio of the amorphous ethylene-propylene copolymer is 15 to 40% by weight.