JP2750749B2 - Resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition suitable for thermoforming such as hot stamping. More specifically, the present invention relates to a resin composition capable of producing a molded article having a surface appearance similar to that obtained by injection molding by thermoforming such as hot stamping molding.

[Conventional technology]

Currently, propylene-based polymer (polypropylene resin)
Is not only excellent in various mechanical properties, but also has good moldability and is relatively chemically stable, so it is widely used in various automobile parts by molding methods such as hot stamping molding and vacuum molding. Is molded. But,
When manufacturing by hot stamping molding method, when filling the molten material into the mold, the temperature difference between the mold and the resin causes uneven cooling, which lowers the product value and uses only mechanical materials is the current situation. For this reason, a product having a surface appearance comparable to a molded product obtained by the injection molding method has not been obtained until now.

[Problems to be solved by the invention]

In improving the material when molding the molten material by hot stamping molding method, since the polypropylene resin is a crystalline material, the following method is used to control cooling unevenness when the polypropylene resin melted on the mold is solidified. The following three methods are conceivable.

(1) Method for slowing down the crystallization rate (2) Decreasing the degree of crystallinity (3) Slowing down the induction time until crystallization starts Means that the cooling of the polypropylene resin is delayed, and the molding cycle becomes long, which is not economical. Also, lowering the crystallinity is
It is not advisable to reduce the mechanical strength of the material and narrow down the value and use of the function itself.

From the above, the present invention is one of the above three methods,
It is an object of the present invention to obtain a material that delays the induction time until crystallization starts (increases the induction time).

[Means and actions for solving the problem]

According to the present invention, these problems are: (A) at 30 ° C. the xylene solubles are at most 5.
0% by weight of a propylene homopolymer; (B) a xylene-insoluble content at a temperature of 30 ° C. of at most 5.
0% by weight and the copolymerization ratio of propylene is 25-75.
(C) a propylene-ethylene random copolymer having an ethylene copolymerization ratio of 1.0 to 10% by weight, and (D) a propylene copolymerization ratio of 15 to 40% by weight. And
And the melt flow rate (according to JISK7201,
14 measured, hereinafter referred to as “MFR”) is 0.01 to 10 g / 10 min, the melting peak measured by a differential scanning calorimeter is 80 ° C. or more, and the crystallinity measured by X-ray is 3% or more. And an ethylene-propylene copolymer having a weight average molecular weight / number average molecular weight of 4 or more, which is an index of the molecular weight distribution measured by gel permeation chromatography, or a composition comprising these polymers and (E) a filler. The composition ratio of the filler in the composition is at most 40% by weight, and the composition ratio of the ethylene-propylene random copolymer in the total amount of the propylene homopolymer and the ethylene-propylene random copolymer Is from 5.0 to 40% by weight, and the MFR of the sum of these polymers is
(Melt flow rate) is 2.0 to 100 g / 10 minutes, and is referred to as “propylene homopolymer, ethylene-propylene random copolymer, propylene-ethylene random copolymer and ethylene-propylene copolymer” (hereinafter referred to as “all polymers”). The total amount of propylene homopolymer and ethylene-propylene random copolymer and the composition ratio of propylene-ethylene random copolymer are 25 to 65% by weight in the total amount of propylene-ethylene random copolymer. The composition ratio of the propylene homopolymer and the ethylene-propylene random copolymer with respect to 1 part by weight of the copolymer is 0.5 to 2.5 parts by weight as the total amount thereof, and the ethylene-propylene copolymer accounts for the entire polymer. Although the composition ratio is at least 5.0% by weight, the ethylene-propylene copolymer and Len - most the composition ratio of the propylene random copolymer as a total amount thereof 60
% By weight of the resin composition. Hereinafter, the present invention will be described specifically.

(A) Propylene homopolymer The propylene homopolymer used in the present invention is 30 ° C.
At most 5.0 x
% By weight (preferably 3.0% by weight or less). The MFR of the polymer is generally 2.0 to 200 g / 10
Minutes, preferably from 5.0 to 200 g / 10 minutes, especially
Those with 5.0 to 180 g / 10 minutes are preferred. When a propylene homopolymer having an MFR lower than the lower limit is used, kneading properties are not good,
Furthermore, the moldability of the composition is not good. On the other hand, when the ratio exceeds the upper limit, the impact resistance of the composition is not good.

(B) Ethylene-propylene random copolymer The propylene copolymerization ratio of the ethylene-propylene random copolymer used in the present invention is 25 to 75.
%, Preferably 30 to 70% by weight, particularly preferably 30 to 60% by weight. Propylene copolymerization ratio of 25% by weight
If less than the ethylene-propylene random copolymer is used, the impact resistance of the composition is not good. On the other hand, an ethylene-propylene random copolymer having a propylene copolymerization ratio of more than 75% by weight is difficult to produce, and even if obtained, there is a problem in the rigidity of the composition.

The ethylene-propylene random copolymer contains at most 5.0% by weight of a component insoluble in xylene at a temperature of 30 ° C.
(Preferably 4.5% by weight or less).

The above propylene homopolymer and ethylene-propylene random copolymer are produced by homopolymerization and copolymerization, respectively, and may be mixed at the composition ratio described below when producing the composition of the present invention. The polymer may be produced by so-called block copolymerization in which ethylene and propylene are copolymerized in the same polymerization vessel or another polymerization vessel in the presence of the polymer and the catalyst system used for producing the polymer.

In any of the above cases, the MFR of the total of the propylene homopolymer and the ethylene-propylene random copolymer
Is 2.0-100 g / 10 min, preferably 5.0-100 g / 10 min,
Particularly, 5.0 to 80 g / 10 minutes is preferable. If the MFR of the total amount of the propylene homopolymer and the ethylene-propylene random copolymer is less than 2.0 g / 10 minutes, the kneading properties and the moldability of the composition will be poor. On the other hand, if it exceeds 100 g / 10 minutes, the mechanical properties of the composition, especially the impact resistance, are poor.

The content of ethylene in the total of these polymers is 3.0 to 30% by weight, preferably 3.0 to 25% by weight, particularly preferably 5.0 to 25% by weight as a monomer unit. If the content of ethylene in the total of these polymers is less than 3.0% by weight as a monomer unit, there is a problem in the impact resistance of the composition. On the other hand, if it exceeds 30% by weight, there is a problem in terms of the rigidity of the composition.

(C) Propylene-ethylene random copolymer Further, the propylene-ethylene random copolymer of the present invention has a copolymerization ratio of ethylene of 1.0 to 10% by weight,
1.5 to 8.0% by weight is desirable, and 2.6 to 7.0% by weight is particularly preferable. If a propylene-ethylene random copolymer having an ethylene copolymerization ratio of less than 1.0% by weight is used, a composition having good impact resistance cannot be obtained. On the other hand, 10
If the content is more than 10% by weight, heat resistance is undesirably reduced.

The propylene-ethylene random copolymer MF
R is 2.0 to 100 g / 10 minutes, preferably 3.0 to 80 g / 10 minutes, and particularly preferably 5.0 to 70 g / 10 minutes for the same reason as in the case of the above-mentioned propylene homopolymer.

(D) Ethylene-propylene copolymer The ethylene-propylene copolymer used in the present invention has a copolymerization ratio of propylene of 15 to 40% by weight, preferably 18 to 40% by weight, particularly preferably 20 to 38% by weight. % Is preferred. When an ethylene-propylene copolymer having a propylene copolymerization ratio of less than 15% by weight is used, the effect of improving the impact resistance of the obtained composition is poor. On the other hand, when the ethylene-propylene copolymer exceeds 40% by weight, the effect of improving the impact resistance of the obtained composition is good, but other mechanical properties (for example, rigidity) are poor.

Further, the MFR of the ethylene-propylene copolymer is 0.01
To 10 g / 10 min, preferably 0.02 to 10 g / 10 min, and particularly preferably 0.05 to 8.0 g / 10 min. If an ethylene-propylene copolymer having an MFR of less than 0.01 g / 10 minutes is used, the resulting composition has poor processability. On the other hand, when an ethylene-propylene copolymer exceeding 10 g / 10 minutes is used, the effect of improving the impact resistance of the obtained composition is not good.

Mooney viscosity of the ethylene-propylene copolymer (ML
_{(1 + 4} , 100 ° C.) is usually from 10 to 150, preferably from 10 to 130, particularly preferably from 10 to 120. If an ethylene-propylene copolymer having a Mooney viscosity of less than 10 is used, the moldability is improved, but the effect of improving impact properties is low,
Layer delamination may occur at the time of gate cutting of a molded product, which may cause trouble. On the other hand, if an ethylene-propylene copolymer exceeding 150 is used, not only dispersion during kneading becomes difficult, but even if a uniform composition is obtained, a flow mark on the surface of the molded product,
Weld lines and the like become noticeable, and a molded article with good appearance cannot be obtained.

Incidentally, the ethylene-propylene copolymer is usually used as a differential scanning calorimeter (DS).
The melting peak measured in C) is 80 ° C or higher, 80-125 ° C
And particularly preferably 85 to 125 ° C. If the melting peak is lower than 80 ° C., the resulting composition has poor rigidity and tensile strength.

Further, the ethylene-propylene copolymer has a crystallinity of 3% or more as measured by X-ray, preferably 3 to 30%,
Particularly, 3 to 25% is preferable. When an ethylene-propylene copolymer having a crystallinity of less than 3% is used, rigidity and tensile strength are poor. On the other hand, if it exceeds 30%, the impact resistance is not good.

Further, the ethylene-propylene copolymer has a weight-average molecular weight ( _w ) / number-average molecular weight ( _n ), which is an index of a molecular weight distribution measured by gel permeation chromatography (GPC), of 4 or more. preferable.
_If an ethylene-propylene copolymer having _w / _n of less than 4 is used, the resulting composition has poor processability.

In producing the composition of the present invention, the above propylene homopolymer, ethylene-propylene random copolymer, propylene-ethylene random copolymer and ethylene-propylene copolymer are uniformly mixed at the composition ratio described below. However, the rigidity of the composition can be further improved by further blending a filler described below with these polymers.

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

In addition, as the organic filler, wood flour, organic fiber, straw,
Rice husks, peanuts, etc.

The wood flour usually has a 12-mesh pass, and preferably has an average particle diameter of 45 mesh or less. Note that the type of the wood flour is not particularly limited.

The organic fibers are animal fibers such as wool, plant fibers such as cotton, jute, and pulp, and synthetic fibers such as generally used vinylon fiber, polyester fiber, nylon fiber, and acrylic fiber. Since the length and average diameter of the organic fibers vary depending on the use of the composition finally obtained, mixing conditions, and the like, they cannot be unconditionally specified, but generally the average system range is 3 to 500 μm, Length of 0.1
Those having a size of ~ 6 mm are preferred.

In addition, straw is cut and used so as to have the same average diameter and length as the organic fibers from the viewpoint of mixing properties.

Moreover, hulls and peanuts are used after being crushed like the wood flour.

(F) Composition ratio In the composition of the present invention, the composition ratio of the ethylene-propylene random copolymer in the total amount of the propylene homopolymer and the ethylene-propylene random copolymer is 5.0 to 40% by weight, ~ 35% by weight is preferred,
7.0-35% by weight is preferred. When the composition ratio of the ethylene-propylene random copolymer in the total amount of the propylene homopolymer and the ethylene-propylene random copolymer is less than 5.0% by weight, the resulting composition has poor impact resistance. On the other hand, if it exceeds 40% by weight, the rigidity of the composition is reduced.

Further, propylene homopolymer, ethylene-propylene random copolymer, propylene-ethylene random copolymer and ethylene-propylene copolymer (that is,
The composition ratio of the propylene homopolymer and the ethylene-propylene random copolymer in the total polymer) is 25 to 65.
% By weight, preferably 30 to 65% by weight, especially 30 to 65% by weight.
60% by weight is preferred. When the composition ratio of the propylene homopolymer and the ethylene-propylene random copolymer in the total polymer is less than 25% by weight, the resulting composition has poor impact resistance. On the other hand, when the content exceeds 65% by weight, the rigidity of the composition is reduced, so that the mechanical strength of the molded article is reduced.

Further, the composition ratio of the propylene-ethylene random copolymer in the total polymer is 25 to 65% by weight,
60% by weight is preferred, and 30-60% by weight is preferred. If the copolymerization ratio of the propylene-ethylene random copolymer in the total polymer is less than 25% by weight, the induction time until crystallization of the obtained composition starts cannot be delayed so as to satisfy the induction time. On the other hand, if it exceeds 65% by weight, not only is the heat resistance reduced, but also the rigidity is reduced, which is not preferable.

Further, the composition ratio of the propylene homopolymer and the ethylene-propylene random copolymer to 1 part by weight of the propylene-ethylene random copolymer is 0.5 to 2.5 parts by weight as the total amount thereof, and 0.5 to 2.0 parts by weight is desirable. In particular, 0.7 to 2.0 parts by weight is suitable. If the total content of the propylene homopolymer and the ethylene-propylene random copolymer is less than 0.5 part by weight per 1 part by weight of the propylene-ethylene random copolymer, the appearance of the molded article is poor. On the other hand, when the amount exceeds 2.5 parts by weight, not only the heat resistance of the obtained composition is not good, but also the rigidity is remarkably reduced, and the composition cannot be applied to products requiring heat-resistant creep.

Further, the composition ratio of the ethylene-propylene copolymer in the total polymer is at least 5.0% by weight. However, if the amount exceeds 30% by weight, the moldability of the resulting composition is not satisfactory. For these reasons, the composition ratio of the ethylene-propylene copolymer in the total polymer is preferably 5.0 to 25% by weight, and particularly preferably 5.0 to 20% by weight.

Further, the composition ratio of the ethylene-propylene copolymer and the ethylene-propylene random copolymer in the total polymer is the total amount (sum) of the obtained compositions as the total amount thereof from the viewpoint of heat resistance and rigidity. At most 60% by weight. However, the composition ratio of these polymers in the total polymer is 5.0% by weight as the total amount of those polymers.
If it is less than 1, the nucleus start induction time is short, cooling unevenness easily occurs, and the appearance is poor. From these facts, the composition ratio of the ethylene-propylene copolymer in the total polymer is desirably 5.0 to 40% by weight as a total amount thereof, and particularly preferably 10 to 35% by weight.
% By weight is preferred.

In producing the composition of the present invention, the propylene homopolymer, ethylene-propylene random copolymer,
The object can be achieved by uniformly mixing the propylene-ethylene random copolymer and the ethylene-propylene copolymer. Further, the rigidity of the composition can be improved by uniformly mixing the filler. At this time, the blending ratio (composition ratio) of the filler in the composition is at most 40% by weight, preferably 1.0 to 40% by weight, and particularly preferably 5.0 to 30% by weight. Composition ratio is 40
It is difficult to obtain a uniform composition exceeding 10% by weight, and even if it is obtained, it is not preferable because the fluidity of the composition is poor, the rigidity does not increase as much as added, and the specific gravity increases.

(G) Production of the composition The composition of the present invention can be produced by uniformly mixing the whole polymer or the whole polymer and the filler, but if necessary, the composition is generally used for olefin-based polymers. Of course, additives such as oxygen, light or heat stabilizers, flame retardants, processability improvers, wetting agents, antistatic agents and pigments used may be added.

The composition may be dry blended using a mixer such as a tumbler, ribbon blender and Henschel mixer, or may be a batch kneader (eg, Banbury mixer) or a continuous kneader (eg, Extruder), but can also be continuously kneaded using a continuous mixer as described above. Further, these methods can be used together (for example, dry-blended and then continuously kneaded) to achieve more uniform mixing.

(H) Molding Method Various molded articles can be produced by subjecting the composition obtained as described above to thermoforming or injection molding such as hot stamping molding generally performed in the field of polyolefin resins.

At the time of thermoforming, it depends on the type of each of the above components and the composition ratio thereof, but usually the molding temperature is 190 to 250 ° C.
It is. In the case of injection molding, the molding temperature is generally 200 to 230 ° C.

[Action]

In the resin composition of the present invention, the propylene homopolymer and an ethylene-propylene copolymer, or a composition comprising these polymers and a filler, the propylene-
Even if each of the ethylene random copolymer and the ethylene-propylene copolymer is independently blended, the induction period up to the start of crystallization, that is, the nucleus start time (τ) can be delayed. However, a resin composition containing any of these polymers cannot provide satisfactory results in other functions. For example, when only a propylene-ethylene random copolymer is blended, the nucleation start time can be lengthened,
The impact strength at low temperatures (cold impact strength), that is, the Izod impact value, is low. On the other hand, when only the ethylene-propylene copolymer is added, although the cold impact resistance is improved, it is not preferable because heat resistance deformation and rigidity decrease are caused. The reason is unknown, but when these propylene-ethylene random copolymers and ethylene-propylene copolymers are used in combination, the nucleation start time is effectively slowed down with a smaller amount of blending than when each is independently blended and the nucleation start time is delayed. be able to.

From these, the induction period leading to the start of crystallization,
That is, the measurement of the nucleation start time, when performing isothermal crystallization using a scanning differential thermal analyzer and performing stamping molding of a material with a long induction time until the start of crystallization at that time,
It was found that good results of the surface appearance were obtained. In the evaluation, if the Aurenius plot is performed at the temperature at which the time of the induction period is rapidly cooled, the induction period at the temperature corresponding to the mold can be estimated. The material can be determined based on the length of time at that time.

[Examples and Comparative Examples]

Hereinafter, the present invention will be described in more detail with reference to examples.

In Examples and Comparative Examples, the nucleation onset time (τ) was measured by using a scanning differential calorimeter as described above until the isothermal crystallization was reached. The Izod impact strength is AS
Notched measurements were made at 23 ° C. and −30 ° C. according to TM D256. The flexural modulus was measured according to ASTM D790. Further, the heat distortion temperature was measured at a load of 4.6 kg / cm ² (66 psi) according to ASTM D648.

In Examples and Comparative Examples, a stamping molding machine whose top view is shown in FIG. 1 and whose side view is shown in FIG. 2 is used, and a door trim (projection area: 4,000 cm ² ) whose perspective view is shown in FIG. The resin temperature is 200 ℃ and the molding pressure is 50k
Stamping molding was performed under the conditions of g / cm ² (a is a mounting hole of a speaker grill). 1 and 2, reference numeral 1 denotes an extruder, and 1a denotes a nozzle. Reference numeral 2 denotes a measuring unit, and reference numeral 3 denotes a hopper. further,
4 is a moving table, and 6 is a cylinder. Reference numeral 7 denotes a hydraulic pump, and reference numeral 8 denotes a press. 8a is a lower die of the press machine, and 8b is an upper die. In addition, 9
Is a control panel. In a stamping molding machine whose plan view is shown in FIG. 1 and whose side view is shown in FIG. 2, the resin composition filled in a hopper 3 is measured by a measuring section 2 of an extruder 1 and passed through a moving table 4 to a hydraulic pump. Pressurized at 7,
It is extruded by the nozzle 1a through the cylinder 6, and the press 8
A certain amount is extruded into the lower mold 8a. The extruded resin composition is pressed by the lower die 8a and the upper die 8b of the press machine 8. In these operations, the control panel 9 controls the temperature, pressure, and the like.

Further, the injection molding uses a mold having a size similar to that of the door trim shown as a perspective view in FIG. 3 formed by the stamping molding and having a similar shape.
Using an injection molding machine of a scale of 1300 tons, the mold temperature was 40 ° C. and the resin temperature was 200 ° C.

The appearance was stamped by the above method, and the appearance of the obtained door trims was the same as that of injection molding in Table 3. The best was "◎", the best was "○", and the one with no gloss at the vacuum molding temperature was shown. “Δ”, worse ones were indicated by “×”, and ones with noticeable cooling marks were indicated by “XX”.

In Examples and Comparative Examples, the propylene homopolymer and ethylene-propylene copolymer used were each subjected to homopolymerization of propylene in a polymerization vessel using a Ziegler-Natta catalyst without using a solvent. Then, ethylene was fed into the polymerization vessel, and a copolymer of ethylene and propylene was produced to produce each mixture.
All propylene homopolymers in the resulting mixture are 30
At a temperature of 0 ° C., the content soluble in xylene was 0%, and in the ethylene-propylene random copolymer, the content insoluble in xylene was 0% at a temperature of 30 ° C. The mixing ratio of the ethylene-propylene random copolymer (hereinafter, referred to as “component B”) in each of the obtained mixtures, the MFR of the propylene homopolymer (hereinafter, referred to as “component A”), and the MFR of the whole mixture were defined as the first. It is shown in the table.

Further, as a propylene-ethylene random copolymer, the copolymerization ratio of ethylene was 2.5% by weight, and the MFR was 50%.
A propylene-ethylene random copolymer having a g / 10 minutes was used. Further, as the ethylene-propylene copolymer, the copolymerization ratio of propylene is 38% by weight, the Mooney viscosity (ML _{1 + 4} , 100 ° C.) is 42, and the MFR is 2.5 g / 10
Min, melting point of 105 ° C and crystallinity of 4%
And an ethylene-propylene copolymer having _w / _n of 5.0 was used. Also, as talc, the average particle size is 2
A talc of μm was used.

Examples 1 to 6 and Comparative Examples 1 to 7 [Table 2] A mixture whose mixing ratio is shown in Table 2 [Comparative Example 6 is a propylene homopolymer having an MFR of 50 g / 10 minutes (hereinafter referred to as “PP”). Use), propylene-
Ethylene random copolymer (hereinafter referred to as "component C"),
Ethylene-propylene copolymer [However, in Comparative Example 7, the copolymerization ratio of ethylene was 28% by weight, the Mooney viscosity (ML _{1 + 4} , 100 ° C.) was 42, and the MFR was 2.0 g / 10 min. And an amorphous ethylene-propylene copolymer rubber having a crystallinity of 0% and _w / _n of 4.1) and talc were dry-blended using a Henschel mixer for 5 minutes in advance. Each of the obtained mixtures was melt-kneaded at a resin temperature of 230 ° C. using an extruder having a biaxial screw (diameter: 45 mm, length: 30 pitches) in the same direction. Each of the obtained compositions (pellets) was subjected to isothermal crystallization using a scanning differential analyzer. As described above, the quenching temperature of the isothermal crystallization is measured at three or more points to measure the induction time until the onset of crystal nuclei, and the Aurenius plot is taken of the reciprocal of the quenching temperature (absolute temperature). The induction time until the start of crystallization at the mold temperature is calculated. The quenching temperature was 115 ° C.

Each of the obtained compositions was injection-molded at a resin temperature of 230 ° C., and test pieces for measuring Izod impact strength and flexural modulus were manufactured, and their physical properties were measured. Table 3 shows the results. Further, the MFR of the composition was measured. Table 3 shows the results.

Further, each composition was subjected to stamping molding under the above-mentioned conditions to form the above-mentioned door trim. Table 3 shows their appearance.

From the results of Comparative Example 6, when the ethylene-propylene random copolymer was not blended, the impact resistance (including the cold impact resistance) was low.
In the case where an amorphous ethylene-propylene copolymer (so-called ethylene-propylene copolymer rubber) is blended in place of the propylene copolymer, the blended amorphous ethylene-propylene copolymer has residual crystals. It is evident that not only the heat resistance of the obtained composition is not good but also the hardness of the surface of the molded article is low.

〔The invention's effect〕

The resin composition of the present invention is not only capable of being injection-molded, but is also capable of being stamped, and can exhibit the following effects, including the resulting molded product.

(1) It is molded integrally with the skin of knit, polyvinyl chloride resin leather, moquette, etc. by stamping molding, and when it is bonded to the skin, it is cooled directly by contact with the side where the skin and the resin composition are bonded. Since the difference between the cooling rates is relatively small on the side of the product, warpage of the obtained product is small.

(2) Even if stamping molding is performed, the molding obtained as in the case of injection molding has no cooling marks and the surface is almost the same.

(3) Good cold shock resistance.

(4) Excellent rigidity (flexural modulus).

(5) Good heat resistance.

(6) Excellent moldability.

The resin composition of the present invention can be used in various fields by injection molding, stamping molding and the like. Typical applications include automotive interior components such as trunk trim, door trim, pillars, rear parcel shelves, instrument panel shelves, instrument panel sesties, and armrests.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for performing stamping molding in Examples and Comparative Examples, and FIG. 2 is a side view of the apparatus. FIG. 3 is a perspective view of a door trim formed in Examples and Comparative Examples. 1 ... Extruder, 1a ... Nozzle 2 ... Measuring unit, 3 ... Hopper 4 ... Moving table, 6 ... Cylinder 7 ... Hydraulic pump, 8 ... Press machine 8a ... Lower die, 8b ... ... Upper mold 9 ... Control panel a ... Mounting holes for speaker grille

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiromitsu Hiromitsu 4-7-23 Meieki Station, Nakamura-ku, Nagoya City, Aichi Prefecture Showa Denko KK Nagoya Branch (56) References JP-A-1-197544 JP-A-1-247441 (JP, A) JP-A-61-247747 (JP, A) JP-A-58-84838 (JP, A)

Claims (1)

(57) [Claims] (A) a propylene homopolymer having a xylene-soluble content of at most 5.0% by weight at a temperature of 30 ° C .; and (B) a xylene-insoluble content of at most 5.% at a temperature of 30 ° C.
0% by weight and the copolymerization ratio of propylene is 25-75.
(C) a propylene-ethylene random copolymer having an ethylene copolymerization ratio of 1.0 to 10% by weight, and (D) a propylene copolymerization ratio of 15 to 40% by weight. And
And a melt flow rate of 0.01 to 10 g / 10 min, a melting peak measured by a differential scanning calorimeter of 80 ° C. or more, and X
Ethylene-propylene copolymer having a crystallinity of 3% or more as measured by a line and a weight average molecular weight / number average molecular weight of 4 or more as an index of molecular weight distribution measured by gel permeation chromatography, or A composition comprising a polymer and (E) a filler, wherein the compositional ratio of the filler in the composition is at most 40% by weight, and the total amount of the propylene homopolymer and the ethylene-propylene random copolymer is The ethylene-propylene random copolymer accounts for 5.0 to 40% by weight of the copolymer, and the total melt flow rate of these polymers is 2.0 to 100 g / 10 minutes. Polymer, propylene-ethylene random copolymer and ethylene-
The total amount of the propylene homopolymer and the ethylene-propylene random copolymer in the total amount of the propylene copolymer and the composition ratio of the propylene-ethylene random copolymer are all 25 to 65% by weight, and the propylene-
The composition ratio of the propylene homopolymer and the ethylene-propylene random copolymer to 1 part by weight of the ethylene random copolymer is 0.5 to 2.5 parts by weight as the total amount thereof, and the ethylene-propylene copolymer accounts for the entire polymer. The composition ratio of the coalescence is at least 5.0% by weight,
A resin composition wherein the composition ratio of the ethylene-propylene copolymer and the ethylene-propylene random copolymer is at most 60% by weight in total.