JPH04153243A - Thermoplastic polymer composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic polymer composition which is excellent in moldability and can give a coating film excellent in adhesion, bending strength, surface hardness and impact resistance by mixing an EPR with a propylene polymer, a linear ethylene polymer and talc in a specified ratio. CONSTITUTION:A thermoplastic polymer composition wherein the thermoplastic polymer component comprises an ethylene/propylene rubber, a propylene polymer and a linear ethylene polymer of a density of 0.93g/cm<3> or above, and 7-25 pts.wt. talc is contained in 100pts.wt. above component wherein the sum of component (A) soluble at 40 deg.C and component (B) insoluble at 40 deg.C and soluble at 110 deg.C and component (B) insoluble at 40 deg.C in the fractionation with o- dichlorobenzene is 50-70 pts.wt., the weight ratio of component (A) to component (B) is 0.7-2.0, and the amount of a component insoluble at 110 deg.C is 50-30 pts.wt.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is composed of an ethylene-propylene rubber, a propylene polymer, a linear ethylene polymer, and talc, and has good processability during injection molding. The present invention relates to a specific thermoplastic polymer composition that has good appearance, excellent flexural modulus, surface hardness, impact resistance, and paintability, and is suitable for injection molded products such as automobile parts.

[Prior art/Problems to be solved by the invention] Improve the fluidity of various rubbers, including ethylene-propylene copolymer rubber (EPR), and give them more rigidity to increase their value as molded products. Many attempts have been made in the past, such as blending polypropylene with rubber, as described in Japanese Patent Publication No. 57-57049, Japanese Patent Publication No. 62-5460, and Japanese Patent Publication No. 62-5461. There is a composition that However, these compositions generally have a low blending ratio of polypropylene, and do not use particularly highly fluid and highly crystalline polypropylene, so when injection molding large molded products, the crystallization rate is slow. It takes a long time to cool down, resulting in extremely poor productivity, and because it is not used in combination with polyethylene or talc, products with insufficient flexural modulus and surface hardness can be obtained.

Furthermore, the composition described in Japanese Patent Publication No. 61-19651, which uses a relatively large amount of polypropylene, is similar in that it is not used in combination with polyethylene or talc.
Moreover, since partially crosslinked rubber is used as the rubber, it has the same problems as the above compositions in terms of productivity, flexural modulus, and surface hardness.

Moreover, contrary to the above technology, there is a composition described in Japanese Patent Publication No. 60-3420 which combines EPR and talc with a propylene-ethylene block copolymer and has both excellent paintability and low-temperature impact resistance. Yes, and by adding polyethylene, the appearance and paintability were improved.
There are compositions described in Japanese Patent Publication No. 52, Japanese Patent Application Laid-Open No. 61-276840, and Japanese Patent Publication No. 6365223.

However, molded articles using these compositions do not necessarily have sufficient bending elastic modulus, and have the problem that they are easily damaged, especially because of their low surface hardness.

[Means for Solving Problem i] The present inventors have improved the impact resistance of the thermoplastic polymer composition,
We studied various methods to solve the problems of moldability, flexural modulus, and surface hardness while maintaining paintability, and blended a highly fluid and highly crystalline polymer substance into ethylene-propylene rubber. I found a method.

As a result of various studies based on this method, we found that by blending ethylene-propylene rubber, propylene polymer, linear ethylene polymer, and talc in specific proportions, the coating film has excellent adhesion and bending elasticity. The inventors have discovered that a specific thermoplastic polymer composition can be obtained that has excellent properties such as hardness, surface hardness, impact resistance, and moldability, and have completed the invention.

That is, in the present invention, the thermoplastic polymer composition is an ethylene-propylene rubber, a propylene polymer, and a density of 0.
Consisting of a linear ethylene polymer of 93 g/d or more,
In the fractionation using 0-dichlorobenzene (ODCB), the component (A) is soluble at 40°C, and the component (A) is insoluble at 40°C.
and the sum of components (B) soluble at 110° C. is 50 to 70 parts by weight, and the weight ratio of components (A) and (B) is 0.
7-2. 0 and 7 to 25 parts by weight of talc is blended to 100 parts by weight of the component (C) which is insoluble at 110°C and 50 to 30 parts by weight. It is a composition.

The thermoplastic polymer composition of the invention preferably provides MF
It has good moldability when R is 10 g/10 minutes or more, and the bending elastic modulus is 10. 000kg/c- or more, Rockwell hardness of 50 or more, Izot impact value at -30°C of 5kg-cIII/cI11 or more, peel strength of the coating film after painting described below of 700g/am or more, and good impact resistance. It is possible to obtain a molded article that has good moldability and improved rigidity and scratch resistance while maintaining paintability.

Since this composition has such excellent properties,
In particular, the present invention is particularly effective when applied to large-sized automobile exterior parts made by injection molding, such as bumpers and air dam spoiler facias, which require painting and where rigidity and scratch resistance are important.

The ethylene-propylene rubber used in the present invention has a Mooney viscosity (ML (100°C)) of 1+4 20 to 80 and a propylene content of 15 to 30% by weight.
(preferably 15 to 25% by weight) has surface hardness,
It is preferably used for the adhesion and impact resistance of the coating film.

The linear ethylene polymer used in the present invention has a density of 0.
．． 93g/ca1 or more (preferably 0.95g/c
ti or more), and those less than the above have poor surface hardness and are unsuitable. Further, the MFR is preferably 10 g/10 minutes or more (preferably 20 g/10 minutes or more) from the viewpoint of coating film adhesion, and even a wax-like coating can provide good coating film adhesion.

The propylene polymer used in the present invention has a VFR of 30
~150g/10 min (preferably 50-100g/10
A propylene-ethylene block copolymer with an ethylene content of 1.5 to 8.0% by weight (preferably 2.0 to 7.0% by weight) is preferred in terms of processability and impact resistance, The density of the crystalline propylene polymerized portion is 0. 90
7g/cd or more (preferably 0.908g/aj or more)
From the viewpoint of surface hardness, these are preferably used.

In addition, the MFR of the above propylene polymer is the one adjusted at the time of polymerization, or the MFR of diacyl peroxide after polymerization.
It may also be one prepared with an organic peroxide such as dialkyl peroxide.

A highly stereoregular catalyst is used in the production of the propylene polymer. A typical manufacturing method for the above catalyst includes reducing titanium tetrachloride with an organoaluminum compound and further treating it with various electron donors and acceptors to obtain a titanium trichloride composition, an organoaluminum compound and an aromatic Method of combining with group carboxylic acid ester (JP-A-56-100806
Publication No. 120712/1983, Japanese Patent Application Laid-Open No. 1982-120712
= 104907), and a supported catalyst method in which titanium tetrachloride and various electron donors are brought into contact with magnesium halide (JP-A-57-63310, JP-A-6
3-43915, Japanese Patent Application Laid-Open No. 63-83116) and the like are used.

In fractionation using 0-dichlorobenzene (ODCB), these three polymer components are separated into a component (A) that is soluble at 40°C and a component that is insoluble at 40°C but soluble at 110°C. The sum of (B) is 50 to 70 parts by weight, and the component (A
) and component (B) is 0.7 to 2.0, and 11
The content of component (C) which is insoluble at 0° C. is 50 to 30 parts by weight.

In the present invention, if the sum of the above components (A) and (B) is less than the above (that is, if the component (C) exceeds the above), the impact resistance and adhesion of the coating film will be poor, and if it exceeds the above, the flexural modulus will be poor. , is unsuitable due to its poor surface hardness. In addition, if the weight ratio of component (B) to component (A) [component (A)/component (B)] is too high, the adhesion of the coating film will be poor in the above grooves, and if it exceeds the above range, the surface hardness will be poor, so it is unsuitable. .

Component (A) preferably has a propylene content of 15 to 35% by weight (preferably 20 to 30% by weight) in terms of impact resistance and surface hardness.

Component (B) preferably has an intrinsic viscosity ([η]) of 1.5 dl/g or less (preferably 1.3 dl/g or less) from the viewpoint of coating film adhesion, and component (C) has an intrinsic viscosity ([η]) of 1.5 dl/g or less (preferably 1.3 dl/g or less). ([η])
2. odt, ”g or less (preferably 1.7 dl/
g or less) is preferable from the viewpoint of moldability.

The crystallinity of the propylene polymer is determined by converting the polypropylene polymer portion in component (B) to component (B), which was determined using 13C-NMR.
D), (ffi/of component (C)) is defined as the index of the proportion of highly crystalline polypropylene.
(Amount of component (C)+amount of component (D))) is preferably 0.75 or more (preferably 0.80 or more) from the viewpoint of surface hardness.

In addition, the ethylene-propylene rubber, propylene polymer, and linear ethylene polymer used in the present invention may be used in combination of two or more types of each component, as long as the component ratio of these compounds by solvent fractionation is within the above range. There is no problem even if it is a mixture.

In addition, this propylene copolymer is a copolymer containing copolymerized (grafted or random) other unsaturated monomers such as maleic anhydride, methacrylic acid, trimethoxy/vinylsilane, or a copolymer thereof. It may be a mixture of. In particular, when crystalline polypropylene grafted with maleic anhydride or trimethoxy vinylsilane is mixed with this propylene copolymer,
゛It has the effect of improving surface hardness.

In addition, the talc used in the present invention is produced by dry crushing followed by rotary classification, and has an average particle size of 5 μm or less (preferably 0.0 μm or less).
．． 5 to 3 μm) and a specific surface area of 3.5 g/g or more (
3.5 to 6 i/g) is suitable. If the average particle size exceeds the above range, the impact resistance tends to be poor, and if the specific surface area is less than the above range, the flexural modulus tends to be insufficient.

This average particle size is the particle size value when the cumulative 1L is 50% by weight, which is read from a particle size cumulative distribution curve measured using a liquid phase sedimentation type light transmission method (for example, CP type manufactured by Shimadzu Corporation, etc.). In addition, the specific surface area can be determined by air permeation method (for example, Shimadzu 5S-
100 type constant pressure ventilation type specific surface area measuring device, etc.).

In addition, the amount of talc is ethylene-propylene rubber,
7 to 25 parts by weight (preferably 1 part by weight) based on 100 parts by weight of the total amount of propylene polymer and linear ethylene polymer
0 to 20 parts by weight).

If it is less than the above, the flexural modulus will be insufficient, and if it exceeds the above, the impact resistance will be poor, which is inappropriate.

Talc may be used untreated, but in order to improve its adhesion or dispersibility with polymers, various organic titanate coupling agents, silane coupling agents,
Those treated with fatty acids, fatty acid metal salts, fatty acid esters, etc. may also be used.

Next, in order for this composition to maintain good impact resistance and paintability, it is preferable that the non-quality parts in the molded article account for 50% by weight or more of the total resin components. Specifically, ethylene-
Regarding the thermoplastic polymer composition composed of propylene rubber, propylene polymer, and linear ethylene polymer, impact resistance and coating properties are determined by having a crystallinity of 50% or less determined by pulse method NMR. This is preferable in terms of film adhesion.

In addition to the above-mentioned components, other additional components can be added to the composition of the present invention within a range that does not significantly impair the effects of the present invention.

Other additional components include additives commonly incorporated into thermoplastic polymer compositions, such as processability stabilizers, antioxidants,
In addition to ultraviolet absorbers, light stabilizers, various soaps including metal soaps, antistatic agents, lubricants, nucleating agents, pigments and pigment dispersants, it is known to give a higher flexural modulus than talc. Whiskers such as fibrous potassium titanate, fibrous magnesium oxulfate, and fibrous aluminum borate, carbon fibers, and the like can be added as necessary.

The composition of the present invention is produced by kneading it using a conventional kneading method, but it is preferable to produce it using a twin-screw extruder. Also,
When the linear ethylene polymer is wax, ethylene-
Propylene rubber and this wax are mixed in a Banbury mixer.
It is desirable to pre-knead the mixture.

The method of molding the composition of the present invention is not particularly limited and may include injection molding, extrusion molding, and blow molding, but the injection molding method is most suitable in view of the effects of the invention.

〔Effect of the invention〕

The composition of the present invention has good processability during injection molding, has a good appearance, and has excellent flexural modulus, surface hardness, impact resistance, and paintability, and is suitable for injection molded products such as automobile parts.

In addition, since the composition of the present invention has a large amount of highly crystalline component (C) compared to conventional thermoplastic polymer compositions,
The cooling solidification rate has been improved, making it possible to shorten the cooling time during injection molding and, in turn, greatly improve the production speed of molded products.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples.

Solvent fractionation in the present invention was carried out according to the following procedure.

■ 5g of sample and antioxidants 2, 6. -di-t-butyl-
1.5 g of p-phenol to 1.5 g of O-dichlorobenzene
1 at 140°C, and then filtered at 140°C using a 0.45 μm Teflon filter in order to filter out insoluble matters such as fillers.

■ After redissolving the filtrate at 140℃, celite (#545)
300 g was added, and the mixture was cooled to room temperature at a rate of 10° C./hour while stirring, and coated on the surface of Celite.

(2) The coated Celite was packed into a cylindrical column, and 0-dichlorobenzene to which the antioxidant was added at the same concentration was transferred into the column and fractionated by elution at 40°C, 110°C, and 140°C.

(2) After the separation, the same amount of methanol was added, filtered through a 0.45 μm Teflon filter, dried under vacuum, and each section was weighed. The proportion of separate categories was determined based on the total weight of each category.

Various measuring methods used in the present invention are as follows.

(1) Intrinsic viscosity: 0.1 to 0.3 g of the above antioxidant added to 0-dichlorobenzene at 140°C
The concentration was measured in the range of /dl and extrapolated to zero concentration.

(2) Component (B) containing polypropylene, 13C
In the NMR spectrum, it was determined using the signal integrated intensity originating from polypropylene carbon around 46.5 ppm based on the TMS standard.

(3) Total crystallinity of resin: Pulse method NMR method (Polymer Experimental Science 18 “Magnetic Resonance of Polymers”: Kyoritsu Publishing P143
~144).

(4) MFR: Based on ASTM-D1238, 2.1
The propylene polymer was measured at 230°C and the ethylene polymer was measured at 190°C using a 6 kg load.

(5) Density: Measured at 23°C in accordance with ASTM-D1505.

(6) Flexural modulus: Based on ASTM-D790, 2
It was measured at 3°C.

(7) Surface hardness + 23 according to ASTM-D785
Rockwell hardness in °C was evaluated on the R-scale.

(8) Impact resistance Based on ASTM-D256, 30℃
It was evaluated using the Izot value.

(9) Adhesion of coating film 2 It was evaluated by the coating peeling strength explained below.

(2) Coating method a: 1.1.1 Expose the test piece of the injection molded product to the boiling vapor of 1.14-lichloroethane for 30 seconds, and then leave it to dry at room temperature for 30 minutes.

51 Next, apply masking tape to the lower half of the test piece surface, leaving the upper half intact.

C3 Next, a polyurethane-modified polyolefin primer for polypropylene (manufactured by Kansai Paint, trade name: Sofresox 2500) was spray-painted to a film thickness of approximately 10 μm, left to dry for 30 minutes at room temperature, and then pasted. Peel off the masking tape.

69 Next, a one-component urethane top coat containing an isocyanate curing agent (manufactured by Nippon Beat Chemical Co., Ltd., trade name: Flexene 105) was sprayed to a film thickness of approximately 80 μm, and the mixture was placed in an air oven at 120°C. After baking for 30 minutes, the coating was left at room temperature for 48 hours and subjected to a coating adhesion test.

■Measurement method a: Apply cellophane adhesive tape to the entire surface of the painted test island, and then use a cutter to make cuts vertically down to the base material every 10+nm width.

b. Peel off the coating film on the side to which the brimer was not applied while keeping the cellophane adhesive tape in close contact with it, bend it 180 degrees, and attach it to a tensile tester.

The test was conducted at C123°C at a tensile rate of 50 dragons/min, and the average value was determined by reading the 10 peak values from the curve drawn at t.

Examples 1 to 5, Comparative Examples 1 to 5 The materials shown in Table 1 were blended with the composition shown in Table 2, and further 2,6
．． -di-t-butyl-p-phenol 0.1 part by weight, tetrakis[methylene-3(3'5'-di-t
-butyl-4'-hydroxyphenyl)propionate] 0.1 part by weight of methane, and 0.5 part of carbon black
Mix 5 parts by weight with a super mixer made by Yoda Seisakusho.
After mixing for a minute, the mixture was kneaded and granulated at 210° C. using an FCM twin-shaft mixer manufactured by Kobe Steel, Ltd. to obtain a composition. In Example 4, ethylene-propylene rubber and linear ethylene polymer were pre-kneaded in a Banbury mixer.

Thereafter, various test pieces were prepared using an injection molding machine with a mold clamping force of 100 tons at a molding temperature of 220° C., and their performance was evaluated according to the above-mentioned 11 standard method.

Table 1 Materials for Examples/Comparative Examples <Ethylene-propylene rubber> Note 1 :ML,・4 100℃ Linear ethylene polymer Propylene polymer Kuta le nine>

Claims (1)

[Claims] 1. The thermoplastic polymer composition is ethylene-propylene rubber, a propylene polymer, and a density of 0.93 g/c.
Composed of a linear ethylene polymer of m^3 or more, o-
In fractionation with dichlorobenzene (ODCB), 4
The sum of component (A) that is soluble at 0 °C and component (B) that is insoluble at 40 °C and soluble at 110 °C is 50 to 70 parts by weight, and component (A) and component (B) The weight ratio of 0.7 to 2
．． 0, and the insoluble component (C) at 110°C is 50 to 3
A thermoplastic polymer composition comprising 7 to 25 parts by weight of talc per 100 parts by weight of the composition, which is 0 parts by weight. 2. The composition according to claim 1, wherein the propylene content of component (A) is 15 to 35% by weight. 3. The intrinsic viscosity ([η]) of component (B) is 1.5 dl/g
or less, and the intrinsic viscosity of component (C) is 2.0 dl/
The composition according to claim 1, wherein the composition has a weight of less than or equal to g. 4. When the polypropylene polymerized moiety in component (B) determined using ^1^3C-NMR is defined as component (D), component (C) and component (D) satisfy the relationship of the following formula. The composition according to claim 1. (Amount of component (C)/(Amount of component (C) + Amount of component (D))) > 0.75 5. The average particle size of talc is 5 μm or less and the specific surface area is 3.5 m^2 2. The composition according to claim 1, wherein the composition has an amount of at least /g. 6. The composition according to claim 1, wherein the thermoplastic polymer component has a crystallinity of 50% or less as determined by pulsed NMR.