JPH0639558B2 - Propylene polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a propylene-based polymer composition having excellent adhesion to polyurethane without using a primer.
More specifically, (A) (1) to treat a propylene-based polymer with (2) an organic compound having at least one unsaturated bond in the molecule and containing a hydroxyl group, and (3) an organic peroxide. The modified propylene-based polymer obtained by (B) propylene-based polymer, (C) Mooney viscosity of 20 to 10
An amorphous ethylene-propylene copolymer of 0 and
(D) relates to a propylene-based polymer composition comprising a high-density ethylene-based polymer, which not only has excellent mechanical properties such as rigidity and low-temperature impact resistance, but also has polyurethane properties without using a primer. It is an object of the present invention to provide a propylene-based polymer composition having good adhesion, excellent weather resistance, and good appearance.

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 manufactured industrially and widely used in various fields as industrial parts such as 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 it is mounted on the vehicle, and the proportion is increasing further in the direction of upsizing of the automobile.

However, as mentioned above, propylene-based polymers are chemically extremely inactive polymeric substances because they do not have polar groups in the molecule. Methods of treating by surface treatment methods such as a corona discharge treatment method, a plasma treatment method, a mechanical surface roughening method, a flame treatment method and an oxygen or ozone treatment method are well known. Further, it is recommended to wash the surface with a solvent such as alcohol or aromatic hydrocarbon prior to the surface treatment. Furthermore, a method is also known in which a molded article is immersed in an organic solvent such as trichlene, perchlorethylene, pentachlorethylene, and toluene at a temperature close to the boiling point or exposed to a solvent vapor (for example, Kenyuki Takagi, Taira Sasaki). Sansan, "Plastic Materials Course, Polypropylene Resin," pages 216 to 219, 1969, published by Nikkan Kogyo Shimbun. However, not only do these methods require equipment for processing, but they also take a considerable amount of time.

Furthermore, it is a reality that a molded article (bumper) is undercoated with a primer capable of adhering to a propylene-based polymer, 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 takes a long time (usually about 1
I need 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.

When manufacturing other automobile parts, tricycle parts, electric appliance parts, electronic appliance parts, etc., when applying propylene polymer and applying polyurethane, the application method is different, but there are the same problems as above. .

Generally, polypropylene or a composition thereof used for bumpers and the like has a combination of an ultraviolet absorber, an ultraviolet stabilizer, an antioxidant and the like added in an arbitrary formulation in order to enhance weather resistance. However, after several years in an actual vehicle, the surface of the molded product is discolored, and chalking or cracking occurs, which is not sufficient at present. further,
The demand for bumper grades with good weather resistance is becoming stronger as automobiles become more upscale and used in rural areas where the climate is bad.

Therefore, as a countermeasure, it is conceivable to increase the conventional weather resistance formulation or add a new additive, but if these are simply increased or added, appearance problems at the time of molding (for example, uneven gloss on the surface or whitening) There are various problems such as the cause of the above, bleeding of the additive added or added to the surface of the molded article after molding, the appearance is deteriorated, and the surface of the molded article is whitened by long-term use in an actual vehicle.

Further, in the field of industrial parts and daily necessities, not only is it excellent in the mechanical properties described above, but it also has good adhesion to polyurethane without the use of a primer, and also has excellent weather resistance. There is a demand for a propylene-based polymer composition having good appearance.

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)? Or it not only improves, but also has good moldability and excellent weather resistance. At the same time, it can adhere to polyurethane without the use of a primer, and has a good appearance (especially gloss). The purpose is to obtain a propylene-based polymer composition.

Means and Actions for Solving Problems According to the present invention, the problems are (A) (1) 100 parts by weight of a mixture of a propylene polymer or a propylene homopolymer and an ethylene-propylene copolymer rubber. (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" (hereinafter referred to as "hydroxyl compound") and (3) an organic peroxide A modified propylene-based polymer obtained by treating 0.01 to 20 parts by weight, (B) a propylene-based polymer, (C) a Mooney viscosity [ML _{1 + 4} , (100 ° C.)] of 20 to 100, and A composition comprising an amorphous ethylene-propylene copolymer having a propylene content of 20 to 50% by weight, and (D) a high-density ethylene polymer having a density of 0.935 g / cm ³ or more. Density ethylene-based polymer The composition ratio is 3.0 to 25 wt%, modified propylene polymer, propylene polymer and an amorphous ethylene - ratio of hydroxyl compound to the total amount 100 parts by weight of the propylene copolymer is a monomer unit 0.01
To 10.0 parts by weight, and the composition ratio of the modified propylene-based polymer in the total amount of the modified propylene-based polymer and the propylene-based polymer is 5 to 90% by weight, and the modified propylene-based polymer occupies the composition. The composition ratio of coalescence is at least 3.
The problem can be solved by the propylene-based polymer composition, which is 0% by weight and the composition ratio of the amorphous ethylene-propylene copolymer is 1.0 to 35% by weight. Hereinafter, the present invention will be specifically described.

(A) Modified propylene-based polymer The modified propylene-based polymer of the present invention is a mixture of a propylene-based polymer and a propylene homopolymer described below and an ethylene-propylene-based copolymer rubber, which is treated with a hydroxyl-based compound and an organic peroxy acid compound. The method of producing the same is described in JP-A-58-154732.
It is described in detail in the specification of the gazette.

(1) Propylene-based polymer The propylene-based polymer used for producing the modified propylene-based polymer of the present invention is a propylene homopolymer, a block copolymer of ethylene containing propylene as a main component and / or an α-olefin. It is selected from a combination and a random copolymer mainly composed of propylene and ethylene and / or α-olefin. In both these block copolymers and random copolymers, the copolymerization ratio of ethylene and α-olefins is at most 20%.
% By weight (preferably 15% by weight or less). Also, α
The olefin has 4 to 12 carbon atoms. Typical examples of the α-olefin include butene-1, hexene-1, 4-
Methylhexene-1 and octene-1 are mentioned.

These propylene-based polymers are industrially produced and used in various fields. The physical properties and production method of these propylene-based polymers are well known.

Further, instead of the propylene-based polymer, it is also possible to use a mixture of a propylene homopolymer and an ethylene-propylene-based copolymer rubber described below in a composition ratio described below. At this time, the ethylene-propylene copolymer rubber used has ethylene and propylene as main components. Examples of the ethylene-propylene copolymer rubber include an amorphous ethylene-propylene copolymer described below.
The content of propylene is 20 to 50% by weight both in the case of the below-mentioned copolymer rubber and the case of the multi-component copolymer rubber. Also,
Mooney viscosity [ML _{1 + 4} , (100 ° C)] is 10 to 50,
10 to 40 is preferable, and 15 to 40 is particularly preferable. When an ethylene-propylene copolymer rubber having a Mooney viscosity of less than 10 is used, the moldability is good, but the adhesion strength with the urethane coating described later is not sufficiently improved. On the other hand, if you use more than 50, flow marks etc. will occur on the surface of the molded product,
It is not good in appearance.

In producing the modified propylene-based polymer of the present invention,
The proportion of the ethylene-propylene copolymer rubber in the total amount of the propylene homopolymer and the ethylene-propylene copolymer rubber is usually at most 40% by weight, preferably 1 to 40% by weight, particularly 2 to 35% by weight is preferred. When the proportion of the ethylene-propylene copolymer rubber in the total amount of the propylene homopolymer and the ethylene-propylene copolymer rubber exceeds 40% by weight, the adhesion strength with the coating film is good, but the molded product is Not only flow marks are generated on the surface, but also the glossiness is reduced.

Melt flow rate of this propylene-based polymer (JIS K7
According to 210, measured under condition 14, hereinafter referred to as "MFR (2)") is usually 0.01 to 100 g / 10 min, 0.01 to 80 g / min due to defects such as moldability and mechanical properties of the resulting composition. Ten
Minutes are preferable, and those of 0.02 to 60 g / 10 minutes are particularly preferable.

(2) Hydroxyl compound Further, the hydroxyl compound is a compound having at least one unsaturated bond (double bond, 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 Peroxides Organic peroxides are generally used as an initiator in radical polymerization and a cross-linking agent for a 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 polymer is 0.1 to 50 parts by weight, preferably 0.2 to 30 parts by weight, particularly 0.3 to 20 parts by weight. Parts are preferred. Propylene polymer 100
Mixing ratio of hydroxyl compound to 0.1 part by weight is 0.1
When the amount is less than the weight part, the effect of improving the adhesion 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 adhesiveness depending on the amount used is not recognized, and rather the original properties of the propylene homopolymer are impaired, which is not preferable.

The mixing ratio of the organic peroxide with respect to 100 parts by weight of the propylene-based polymer is 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight, and particularly preferably 0.1 to 7 parts by weight.
When the mixing ratio of the organic peroxide is 0.01 parts by weight or less with respect to 100 parts by weight of the propylene polymer, 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 original excellent mechanical properties of the polymer are deteriorated, which is not desirable in any case.

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

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

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) propylene-based polymer Further, the propylene-based polymer used with the composition of the present invention together with this modified propylene-based polymer is MFR (2),
It is of the same kind as the propylene polymer used in producing the modified propylene polymer (however, it does not have to be the same as that used in producing the modified propylene polymer). Of these propylene-based polymers, block copolymers and random copolymers are preferably used.

The MFR (2) of this propylene polymer is usually 1.0 to 100 g / 10.
Minutes, 1.0 to 80 g / 10 minutes are desirable, and especially 2.0 to
60 g / 10 min is preferred. If a propylene-based polymer having an MFR (2) of less than 1.0 g / 10 minutes is used, not only the kneadability with the modified propylene-based polymer is poor, but also the moldability of the resulting composition is poor. On the other hand, when a propylene-based polymer exceeding 100 g / 10 minutes is used, the mechanical strength of the obtained composition is poor.

(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 be improved, but layer separation may occur when the molded article is gate carted, which may cause trouble. 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 manufacturing method is also widely known.

The amorphous ethylene-propylene copolymer is a copolymer rubber obtained by copolymerizing ethylene and propylene and ethylene and propylene as main components,
A linear or branched diolefin containing two double bonds at the ends, such as 1,4-pentadiene, 1,5-hexadiene and 3,3-dimethyl-1,5-hexadiene, 1,
Terminated linear or branched diolefins such as 4-hexadiene and 6-methyl-1,5-heptadiene or bicyclo [2,2,1] -heptene-2 (norbornene) and its derivatives (eg ethylidene norbornene) Are roughly classified into multi-component copolymer rubbers obtained by copolymerizing a small amount of a monomer having a double bond such as a cyclic diene hydrocarbon (generally 10% by weight or less).

(D) High Density Ethylene Polymer The high density ethylene polymer used in the present invention is an ethylene polymer having a density of 0.935 g / cm ³ or more, and has a density of 0.935 g / cm ³ to 0.980 g / cm ^{3. 3} is preferable, and 0.935 to 0.975 g / cm ³ is preferable. The ethylene-based polymer is generally a homopolymer of ethylene and ethylene and α-olefin (the carbon number is generally 3 to 12,
It is preferably a copolymer with 3 to 8). Suitable α-olefins include propylene, butene-1, hexene-1, 4-methylpentene-1 and octene-1.

This high-density ethylene-based polymer has a melt flow index [measured under conditions of 4 according to JIS K7210;
(1) ”] is generally 0.5 to 100 g / 10 min.
-80g / 10min is preferable, especially 1.0-60g / 1
The one of 0 minutes is preferable. If a high-density ethylene polymer with MFR (1) of less than 0.5 g / 10 min is used, not only it is difficult to uniformly disperse it during kneading, but it also causes flow marks on the surface of the obtained molded product. . On the other hand, 100 g / 1
If an ethylene-based polymer exceeding 0 minutes is used, it is still difficult to uniformly disperse it during kneading, and the resulting composition has poor impact resistance.

(E) composition ratio The composition ratio of the high-density ethylene-based polymer in the composition obtained in the present invention is 3.0 to 35% by weight, and 3.0 to 20% by weight.
% By weight is preferred, with 5.0 to 20% by weight being preferred. The composition ratio of the high-density ethylene polymer in the obtained composition is 3.0.
When the content is less than 10% by weight, not only the effect of improving the impact resistance of the resulting composition is poor, but also the appearance of the molded product is not good (particularly, the glossiness is not satisfactory). On the other hand, if it exceeds 25% by weight, the heat resistance of the resulting composition is not satisfactory.

The composition ratio of the modified propylene-based polymer in the total amount (total) of the modified propylene-based polymer and the propylene-based polymer is 5 to 90% by weight, preferably 10 to 80% by weight, and particularly 20 -60% by weight is preferred. When the composition ratio of the modified propylene-based polymer in the total amount of the modified propylene-based polymer and the propylene-based polymer is less than 5% by weight, the adhesiveness between the composition and the polyurethane is poor. on the other hand,
If it exceeds 90% by weight, impact resistance at low temperature becomes insufficient.

Furthermore, the composition ratio of the modified propylene-based polymer in the composition is at least 5% by weight, preferably 5 to 20% by weight, particularly preferably 5 to 15% by weight. When the composition ratio of the modified propylene polymer in the composition is less than 5% by weight, the adhesion between the composition and polyurethane is not good.

The composition ratio of the amorphous ethylene-propylene copolymer in the composition is 1.0 to 35% by weight, preferably 2.0 to 35% by weight, and most preferably 3.0 to 35% by weight.
When the composition ratio of the amorphous ethylene-propylene copolymer in the composition is less than 1.0% by weight, the composition has poor impact resistance at low temperature. On the other hand, when the amount exceeds 35% 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, the total amount of modified propylene-based polymer, propylene-based polymer and amorphous ethylene-propylene copolymer is 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,
0.1 to 10.0 parts by weight is preferable, and 0.2 to 5.0 parts by weight is particularly 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-based polymer, propylene-based polymer, amorphous ethylene-propylene copolymer and high-density ethylene-based polymer The mixing method may be applied so that the composition ratio is within the above range, and the mixing method is generally carried out in the field of olefin polymers, and the mixture may be mixed uniformly. 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
Stabilizers generally added (added) to olefin polymers against heat, oxygen or ultraviolet rays, metal deterioration inhibitors, plasticizers, flame retardants, lubricants, fillers, colorants, antistatic agents and electrical properties. Additives such as improvers may be blended according to the purpose of use of the composition, as long as the physical properties of the composition are not substantially impaired.

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-based polymer of the present invention has excellent adhesion with polyurethane,
Polyurethane can be directly applied to the surface of the molded product without applying the primer to the surface of the molded product (the use of the primer further improves the adhesion).

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
Measured according to D256. 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 leaving it for about 15 minutes, apply urethane paint (trade name, R266, Wackertop, manufactured by Nippon Py Chemical Co., Ltd.) to a dry thickness of 30-40 microns, and keep it at 90 ° C.
Dried for 30 minutes. Then, at room temperature (temperature 23 ℃,
It was left for 48 hours in a humidity of 65%). 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 glossiness is measured by JIS K-71
Measured according to 05. In the weather resistance test, the flat plate test piece was cut into 50 mm × 50 mm, and the black panel temperature was measured using a sunshine weatherometer (manufactured by Suga Test Instruments).
Irradiation was carried out under conditions of 83 ° C. and rainfall conditions of 12 minutes / 60 minutes, and the samples were taken out at each irradiation time, and changes in the appearance of the sample were observed. The results are shown below.

◎: No change ○: Slight chalking △: Cracking ×: Violent cracking Incidentally, the modified propylene polymer, propylene polymer, amorphous ethylene-propylene copolymer rubber used in Examples and Comparative Examples, high The physical properties of the density ethylene polymer and other composition components, the production method, and the like are shown below.

[(A) modified propylene homopolymer]

As a modified propylene homopolymer, MFR (2) 0.5g / 10
85 parts by weight of a propylene homopolymer and 15 parts by weight of an amorphous ethylene-propylene copolymer having a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 20 parts, 3.0 parts by weight of 2-hydroxyethyl methacrylate and 0.7 parts by weight. Part of 2,2'-bis (tertiary-butylperoxyisopropyl) benzene was previously dry blended for 5 minutes using a Henschel mixer. Extruder with a vent (diameter 65m
m, a cylinder temperature of 160 to 200 ° C.) was used for kneading (hereinafter referred to as “modified PP”).

[(B) ethylene-propylene block copolymer] As an ethylene-propylene block copolymer, MFR (2)
Of ethylene-propylene block having an ethylene content of 9.1 g / 10 min [ethylene content of 8.8% by weight, hereinafter referred to as "PP (A)"], MFR (2) of 6.0 g / 10 min ethylene-propylene block Copolymer [ethylene content 10.1% by weight, hereinafter referred to as "PP (B)"], MFR (2) 100 g / 10 min ethylene-propylene block copolymer [ethylene content 8.5
% By weight, hereinafter referred to as "PP (C)"] was used.

[(C) propylene homopolymer]

As the propylene homopolymer, a propylene homopolymer having an MFR (2) of 10 g / 10 minutes [hereinafter referred to as "PP (D)"] was used.

[(D) ethylene-propylene random copolymer]

As an ethylene-propylene block copolymer, MFR (2)
Is 13 g / 10 min, ethylene content is 3.1% by weight, ethylene-propylene random copolymer [hereinafter referred to as "PP
(E) ”is used.

[(E) 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 "EPR (a)" And Mooney viscosity [ML _{1 + 4} ,
An amorphous ethylene-propylene copolymer having a (100 ° C.) of 15 [propylene content of 27% by weight, hereinafter referred to as “EPR (b)”] was used.

((F) high density ethylene polymer)

As a high-density ethylene-based polymer, an ethylene-butene-1 copolymer having a density of 0.945 g / cm ³ [MFR (1) 0.7 g / 10
Min, hereinafter referred to as "HDPE (1)" and density is 0.960 g / cm
^An ethylene homopolymer of ³ [MFR (1) 20 g / 10 min, hereinafter referred to as "HDPE (2)"] was used.

((G) stabilizer)

As various stabilizers, bis (2,2,6,6-tetramethyl-4
-Piperidine sebacate [hereinafter referred to as "stabilizer (1)"], 2 (3-tertiary-butyl-5-methyl-2-hydroxyphenyl-5-chlorobenzotriazole [hereinafter referred to as "stabilizer (2)" ] And tetra [methylene-3-
(3,5-di-tert-butyl-4-hydroxyphenyl)
Propionate] Methane [hereinafter referred to as "stabilizer (3)"]
I used.

Examples 1 to 13 and Comparative Examples 1 to 3 Modified propylene-based polymers, propylene-based copolymers (as PP-based resins), whose blending amounts are shown in Table 1, amorphous ethylene-propylene copolymers Coalesced, propylene homopolymer (as PP resin), high density ethylene polymer and 0.3 parts by weight talc (average particle size 2.0 microns,
The crystallization nucleating agent) was mixed for 5 minutes using a super 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). Flatten each pellet with a 5 ounce injection molding machine (thickness 2 mm, 130 x 130).
mm), a sample for flexural modulus measurement, and a sample for Izod impact strength measurement were manufactured. Each of the obtained test pieces was subjected to coating film adhesion strength, Izod impact strength (measurement temperature −20 ° C.) and flexural modulus, and gloss test and weather resistance test. The results are shown in Table 2.

From the results of the above Examples and Comparative Examples, the propylene-based polymer composition obtained by the present invention has not only excellent mechanical strength (flexural modulus, impact resistance) but also good processability. It is also clear that the adhesiveness with polyurethane is also excellent. Furthermore, it is clear that the most distinctive effect is that not only the effect which can be called a synergistic effect is exhibited by adding a stabilizer against heat, oxygen and ultraviolet rays, but also the appearance (glossiness) is good. .

Effects of the Invention The propylene-based polymer composition obtained by the present invention is
Compared with conventional propylene polymer compositions, the following effects are exhibited.

(1) Workability and moldability are equal or higher.

(2) The weather resistance is good because it exerts a synergistic effect as described above.

(3) The adhesiveness with the polyurethane paint is excellent, and the primer undercoating step can be omitted by applying the polyurethane paint on the surface.

(4) A product having a good gloss and a good appearance can be obtained even if a molded product is partially coated.

(5) Applying a commonly used activation treatment method (for example, corona discharge treatment, plasma treatment method, ultraviolet treatment method) to the surface of the molded product to further improve the adhesion to the polyurethane coating. It is possible to

The propylene-based polymer composition of the present invention can be used in various fields in order to exert the above effects. Typical applications include exterior parts such as automobile bumpers and bumper corners, interior parts such as door liners, and motorcycle parts such as fenders.

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Claims (4)

[Claims] 1. A mixture of 100 parts by weight of (1) a propylene polymer or a propylene homopolymer and an ethylene-propylene copolymer rubber, and (2) at least one unsaturated bond in a molecule, and a hydroxyl group. A modified propylene-based polymer obtained by treating 0.1 to 50 parts by weight of a group-containing organic compound and (3) 0.01 to 20 parts by weight of an organic peroxide, 2. A propylene-based polymer, 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 a high density ethylene polymer having a density of 0.935 g / cm ³ or more, wherein the composition ratio of the high density ethylene polymer in the composition is 3.0 to 25% by weight. A modified propylene-based polymer, a ratio of the organic compound containing a hydroxyl group relative to 100 parts by weight of the total amount of the propylene-based polymer and the amorphous ethylene-propylene copolymer is 0.01 to 10.0 parts by weight as a monomer unit, and modified The composition ratio of the modified propylene polymer in the total amount of the propylene polymer and the propylene polymer is 5 to 90% by weight, and the composition ratio of the modified propylene polymer in the composition is at least 5.0% by weight. And the composition ratio of the amorphous ethylene-propylene copolymer is 1.0 to 35% by weight.