JPS642616B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION This invention relates to reinforced polypropylene compositions. More specifically, the present invention relates to a reinforced polypropylene composition containing an inorganic filler suitable for producing a molded article having high rigidity and high heat resistance. Glass fiber-reinforced polypropylene compositions are widely used in various fields as materials suitable for producing molded articles with high rigidity and high heat resistance. However, when a particularly large molded product is produced from a glass fiber reinforced polypropylene composition, the resulting molded product has no problems in terms of rigidity and heat resistance, but the molded product may warp (deform).
tends to become large, which is a problem when using a glass fiber reinforced polypropylene composition as a molding material for large molded products. Many studies have been made to solve these problems, but glass fiber-reinforced polypropylene compositions that can reduce warpage in molded products have high rigidity and high heat resistance. Other problems often occur, such as deterioration of the characteristics of the device, and therefore, no fully satisfactory improvement measures are known yet. The present invention provides a glass fiber-containing reinforced polypropylene composition that can reduce the "warpage" of a molded product without reducing its original characteristics of high rigidity and high heat resistance. That is, the present invention uses as a resin component (a) a crystalline ethylene/propylene block copolymer with an ethylene component content of 2 to 30% by weight, an organosilane compound having an ethylenically unsaturated bond, or an unsaturated compound having a polar group; , and an organic peroxide, and (b) ethylene propylene rubber, 0 to 20 parts by weight of component (b) per 100 parts by weight of component (a). and (c) 10 to 40 parts by weight of glass fiber, and (d) 0.5 to 0.5 to 0.5 parts of mica surface-treated with an aminosilane compound, per 100 parts by weight of the composition as inorganic filler components.
10 parts by weight, and (e) 1 to 10 parts by weight of wollastonite surface-treated with an aminosilane compound, and the total amount of resin components is 50 to 85 parts by weight of the total amount of the composition.
A reinforced polypropylene composition is provided by melt-mixing a mixture in which the total amount of inorganic filler components is 15 to 50% by weight based on the total amount of the composition. Next, the present invention will be explained in detail. As mentioned above, the resin component used to obtain the reinforced polypropylene composition of the present invention is a crystalline ethylene/propylene block copolymer (hereinafter, crystalline EP block copolymer) having an ethylene component content of 2 to 30% by weight. Modified polypropylene obtained by melt-mixing a mixture of organic peroxide, an organic silane compound having an ethylenically unsaturated bond or an unsaturated compound having a polar group, and an organic peroxide. Component (a) is preferably added to 100 parts by weight of the modified polypropylene in an amount of up to 20 parts by weight of (b) ethylene propylene rubber. The crystalline ethylene/propylene block copolymer for preparing component (a) above has a particularly low ethylene component content in consideration of practical performance, such as the balance between rigidity and impact resistance. 3～
It is preferable to use one within the range of 15% by weight. In terms of physical properties, ASTM D-1238
The melt index (melt flow rate: MFR) measured according to the measurement method specified in
Preferably, the copolymer has an MFR in the range of 1 to 15 g/10 min. The organosilane compound having an ethylenically unsaturated bond used to prepare modified polypropylene is an organosilane compound having an ethylenically unsaturated bond such as a vinyl group, an allyl group, or a methacryloxy group. Examples include methoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, and γ-methacryloxypropyltrimethoxysilane. In place of the organosilane compound having an ethylenically unsaturated bond, an unsaturated compound having a polar group (for example, maleic acid and its derivatives) may be used. In the present invention, the amount of the organic silane compound having an ethylenically unsaturated bond or the unsaturated compound having a polar group is in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the crystalline EP block copolymer. is preferable, and the more preferable range is 0.3 to 1
Parts by weight. The organic peroxide used in combination with the above organosilane compound to prepare modified polypropylene is one whose half-life is 1 minute at a temperature near the melting temperature of the crystalline EP block copolymer, such as t -butylperoxyacetate, t-butylperoxybenzoate, dicumyl peroxide, and the like. A mixture consisting of a crystalline EP block copolymer, an organosilane compound having an ethylenically unsaturated bond or an unsaturated compound having a polar group, and an organic peroxide is melt-mixed to obtain the modified polypropylene used in the present invention. The operation can be conveniently carried out, for example, by a method consisting of passing this mixture through an extruder under heating to produce pellets of modified polypropylene.
The crystalline EP block copolymer used in this case is
It is desirable that the material does not contain additives that may be decomposed by organic peroxides during the melt-mixing process and cause color development or bad odors. Furthermore, the heat treatment of the above mixture is preferably carried out in such a way that all the organic peroxides are decomposed during the heat treatment in order to avoid decomposition of various additives added later. In addition, it is desirable that the melt-mixing treatment of the above-mentioned mixture is performed so that the MFR of the resulting modified polypropylene does not exceed 120 g/10 minutes.
Modified polypropylene with an MFR greater than 120 g/10 minutes is difficult to pelletize and is not preferred in practice. The melt flow rate (MFR) of the modified polypropylene obtained as described above is determined by the MFR of the crystalline EP block copolymer, the content of organic peroxide in the mixture containing the crystalline EP block copolymer, and the content of the organic peroxide in the mixture containing the crystalline EP block copolymer. However, the temperature of the heating melting process depends on the crystallinity used.
The time is determined depending on the properties of the EP block copolymer, and the time required for all of the added organic peroxide to decompose.
Since the time required for the modified polypropylene to contain no organic peroxide is preferable, the MFR of the modified polypropylene is preferably controlled by the amount of organic peroxide used. The amount of organic peroxide added cannot be determined uniformly because it varies depending on the type of organic peroxide, the MFR of the crystalline EP block copolymer, and the MFR of the desired modified polypropylene.
About 0.1 to about 100 parts by weight of EP block copolymer
The amount is preferably 0.5 parts by weight. If the amount added is less than this lower limit, the reaction between the crystalline EP block copolymer and the organic silane will not take place sufficiently, and therefore the physical properties of the composition, which is the object of the present invention, will not be sufficiently improved. Furthermore, if the amount added is greater than the above-mentioned upper limit, the MFR of the modified polypropylene tends to become too large, which also goes against the objective of improving the physical properties of the composition of the present invention. Component (b) of the present invention, ie, ethylene-propylene rubber, is not an essential component in the reinforced polypropylene composition of the present invention. However, when this component (b) is added in a certain amount [20 parts by weight or less, preferably 1 to 5 parts by weight per 100 parts by weight of component (a)], the physical properties of the reinforced polypropylene composition of the present invention are further improved. Therefore, it is preferable to add this. Such ethylene-propylene rubber preferably has a propylene component content of 20 to 50% by weight. Incidentally, as the resin component of the composition of the present invention, an unmodified crystalline EP block copolymer may be further added. Even if this unmodified crystalline EP block copolymer is the same as the crystalline EP block copolymer used as the raw material for modified polypropylene,
Alternatively, it may be a different crystalline EP block copolymer. However, the proportion of the unmodified crystalline EP block copolymer in the resin component must be 90% by weight or less. Among the inorganic filler components used in the present invention
The glass fiber as component (c) is used in an amount of 10 to 40 parts by weight (preferably 20 to 35 parts by weight) per 100 parts by weight of the reinforced polypropylene composition. The glass fibers are preferably short fibers having an average fiber diameter of 10 to 20 μm and an average fiber length of 3 to 15 mm. Further, the glass fibers may be surface-treated with a surface treatment agent for glass fibers such as n-(dimethoxymethylsilylpropyl)ethylenediamine, n-(trimethoxysilylpropyl)ethylenediamine, or the like. Among the inorganic filler components used in the present invention
The mica component (d) is surface-treated with an aminosilane compound. Examples of such aminosilane compounds include α-aminoethyltriethoxysilane, γ-aminopropyltrimethoxysilane, α-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane,
α-aminobutyltriethoxysilane, and
Examples include N-β-aminoethyl-γ-aminopropyltrimethoxysilane. These aminosilane compounds are usually added in an amount of 0.05 to 2 parts by weight per 100 parts by weight of mica.
The surface treatment of mica with this organic silane compound may be carried out either before mixing with resin or the like or during melt mixing with resin or the like. The above mica is a reinforced polypropylene composition
It is used in an amount of 0.5 to 10 parts by weight (preferably 1 to 5 parts by weight) per 100 parts by weight. This mica is generally one that passes through an 80-mesh standard sieve, but it is particularly preferably one that passes through a 200-mesh standard sieve. Also, this mica is
It is preferable that the film is made of thin flakes having an aspect ratio of 20 to 70. Among the above-mentioned inorganic filler components, component (e), wollastonite, is surface-treated with an aminosilane compound. Examples of such aminosilane compounds include the compounds already listed for mica, and the surface treatment conditions are the same as for mica. The above-mentioned wollastonite is used in an amount of 1 to 10 parts by weight (preferably 1 to 5 parts by weight) per 100 parts by weight of the reinforced polypropylene composition. This wollastonite preferably has an average particle size of 1 to 10 microns. There are no particular restrictions on the melt-mixing method for producing the reinforced polypropylene composition of the present invention from each of the components described above. Melt mixing operations using mixers, continuous mixers, rolls, etc. can optionally be utilized. Furthermore, the reinforced polypropylene composition of the present invention has
It can be easily made into a molded article by common processing methods such as injection molding, extrusion molding, blow molding, compression molding, roll molding, lamination molding, vacuum molding, pressure molding, and stamp molding. When the reinforced polypropylene composition of the present invention is molded into a molded product, the molded product has practically sufficient tensile strength, bending strength, and hardness, and is also excellent in other physical properties such as falling ball impact strength. ing. In particular, when the reinforced polypropylene composition of the present invention is molded into a large molded article,
Compared to conventionally known molded products made from glass fiber-reinforced polypropylene compositions, the molded product has significantly improved warpage, and has been reduced to a level that does not pose a problem in practical use. do. Therefore, the reinforced polypropylene composition of the present invention solves the problem of reducing "warpage" without reducing the strength and heat resistance of molded products, which could not be achieved with conventional glass fiber reinforced polypropylene compositions. For example,
It is particularly useful as a reinforced polypropylene composition suitable for manufacturing molded articles used in applications that require large molded articles that are resistant to deformation, such as core materials for automobile parts. Next, a manufacturing example of the reinforced polypropylene composition of the present invention and measurement results of various physical properties of a molded article obtained by molding the reinforced polypropylene composition will be shown. In each example, "parts" are "parts by weight"
and "%" means "% by weight". Example 1 Powdered crystalline ethylene/propylene block copolymer (MFR: 1.0, ethylene component content: 5.5%)
To 100 parts, add 0.5 part of γ-methacryloxypropyltrimethoxysilane as an organic silane compound and 0.25 part of t-butyl peroxybenzoate as an organic peroxide, mix thoroughly with a Henschel mixer, and then add Set temperature of 240
℃ in an extruder (manufactured by Nippon Steel Corporation) for 2 minutes to form modified polypropylene pellets (diameter: 2
-3 mm, length: 3-5 mm) were prepared. The melt flow rate (MFR) of the obtained modified polypropylene was 14 g/10 minutes. To 65 parts of this modified polypropylene, 30 parts of short glass fiber (product name: CS-3PE-475, manufactured by Nittobo Co., Ltd.),
1 part of mica (325 mesh standard sieve, product name: 325S, manufactured by Kuraray Co., Ltd.), 4 parts of wollastonite (product name: JET-30W, manufactured by Asada Seifun Co., Ltd.), and N-β-( 0.025 part of (aminoethyl)-γ-aminopropyltrimethoxysilane (surface treatment agent) was added and thoroughly mixed in a tumbler. This mixture was pelletized using an extruder at a temperature set at 240° C. at the forefront of the cylinder, and the pellets were injection molded to prepare test pieces. Table 1 shows the physical properties of the obtained test piece. In addition, after pelletizing the above mixture using an extruder, this pellet was injection molded to create a disk-shaped test piece (diameter: 200 mm, thickness: 2 mm),
The "warpage" of this disk-shaped test piece was measured by the method described below and is shown in Table 1. Method for measuring “warpage” After leaving the test piece at room temperature for 40 hours, place it on a surface plate with the outer side of the “warp” facing down. Measure the distance (height) between the two ends (at each position) and the surface plate, average the distances, divide that value by the diameter of the test piece (200 mm), and then multiply by 100. was called "sled". Example 2 A test piece was prepared in the same manner as in Example 1, except that the amount of mica added was 2 parts and the amount of wollastonite added was 3 parts, and various physical properties and "warp" were determined in the same manner. was measured. The measurement results are shown in Table 1. Example 3 A test piece was prepared in the same manner as in Example 1, except that the amount of mica added was 4 parts and the amount of wollastonite added was 1 part, and various physical properties and "warp" were determined in the same manner. was measured. The measurement results are shown in Table 1.

[Table] Examples of target values for each of the above-mentioned physical properties and "warpage" required when manufacturing large molded products such as core materials for automobile parts are listed below. MFR: 5-30, specific gravity: 1.2 or less, TYS: 400 or more, FS: 600 or more, FM-1: 40000 or more, FM-
2: 25000 or more, Izod: 5 or more, HDT: 135 or more,
Warpage: 3.5 or less Comparative Example 1 The amount of modified polypropylene added was changed to 60 parts, 5 parts of ethylene propylene rubber (propylene component content: 27%) was added, the amount of mica added was changed to 5 parts, and wullast was added. A test piece was prepared in the same manner as in Example 1, except that no night was added, and various physical properties and "warpage" were measured in the same manner.
The measurement results are shown in Table 2. Example 4 Mica was mixed with mica having a large particle size (passed through a 200 mesh standard sieve, product name: 200HK, manufactured by Kuraray Co., Ltd.)
except that the addition amount was changed to 2.5 parts, and the addition amount of wollastonite was also 2.5 parts.
A test piece was prepared in the same manner as in Example 1, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 2. Example 5 The amount of modified polypropylene added was changed to 45 parts, and unmodified polypropylene (pellet-like crystalline ethylene/propylene block copolymer, MFR: 9.0,
A test piece was prepared in the same manner as in Example 1, except that 20 parts of ethylene component content: 5.5%) was added, the amount of mica added was 2.5 parts, and the amount of wollastonite added was 2.5 parts. Various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 2.

[Table] Example 6 Example 1 except that the amount of mica and wollastonite added was 2.5 parts each, the amount of modified polypropylene added was changed to 70 parts, and the amount of short glass fiber added was changed to 25 parts. Test pieces were prepared in the same manner as above, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 3. Example 7 The procedure was the same as in Example 1, except that the amounts of mica and wollastonite were each 2.5 parts, the amount of modified polypropylene was changed to 75 parts, and the amount of short glass fibers was changed to 20 parts. A test piece was prepared using the same method, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 3. Comparative Example 2 A test piece was prepared in the same manner as in Example 1, except that wollastonite was not added and the amount of mica added was changed to 5 parts, and various physical properties and "warpage" were measured in the same manner. . The measurement results are shown in Table 3.

[Table] Comparative Example 3 Except that the amount of modified polypropylene added was changed to 80 parts, the amount of short glass fiber added was changed to 5 parts, the amount of mica added was changed to 10 parts, and the amount of wollastonite was changed to 5 parts. A test piece was prepared in the same manner as in Example 1, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 4. Comparative Example 4 Same as Example 1 except that the amount of modified polypropylene added was changed to 60 parts, the amount of short glass fiber added was changed to 20 parts, the amount of mica added was changed to 15 parts, and wollastonite was changed to 5 parts. Test pieces were prepared in the same manner, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 4. Comparative Example 5 Same as Example 1 except that the amount of modified polypropylene added was changed to 60 parts, the amount of short glass fiber added was changed to 20 parts, the amount of mica added was changed to 5 parts, and wollastonite was changed to 15 parts. Test pieces were prepared in the same manner, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 4.

[Table] Comparative Example 6 A test piece was prepared in the same manner as in Example 1, except that 5 parts of calcium carbonate (average particle size 0.7μ) was used instead of mica and wollastonite (no surface treatment agent was added). Then, various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 5. Comparative Example 7 A test piece was prepared in the same manner as in Example 1, except that 5 parts of talc (average particle size 3 to 4 μm) was used instead of mica and wollastonite (no surface treatment agent was added). Various physical properties and "warpage" were measured. The measurement results are shown in Table 5. Comparative Example 8 A test piece was prepared in the same manner as in Example 1, except that mica and its surface treatment agent were not added and the amount of wollastonite added was changed to 5 parts, and various physical properties and " The warpage was measured. The measurement results are shown in Table 5.

【table】

[Table] Comparative Example 9 Using the same amount of a modified polypropylene homopolymer (MFR: 14 g/10 min) as modified polypropylene, changing the amount of short glass fibers added to 35 parts, and mica (and its surface treatment agent) A test piece was prepared in the same manner as in Example 1, except that both the material and wollastonite were not added, and various physical properties and "warpage" were measured in the same manner. The measurement results are shown in Table 6. Comparative Example 10 The same amount of modified polypropylene homopolymer (MFR: 14 g/10 min) was used as the modified polypropylene, the amounts of mica and its surface treatment agent were changed to 35 parts and 0.175 parts, respectively, and short glass fibers and wax were used. A test piece was prepared in the same manner as in Example 1, except that neither of the lastonites was added, and various physical properties and "warpage" were measured in the same manner.
The measurement results are shown in Table 6.

【table】

Claims (1)

[Scope of Claims] 1. As a resin component, (a) the ethylene component content is 2 to 30;
% by weight of a crystalline ethylene/propylene block copolymer, an organosilane compound having an ethylenically unsaturated bond or an unsaturated compound having a polar group,
and (b) modified polypropylene obtained by melting and heating a mixture consisting of an organic peroxide.
Contains ethylene propylene rubber in a proportion of 0 to 20 parts by weight of component (b) per 100 parts by weight of component (a), and (c) glass as an inorganic filler component per 100 parts by weight of the composition. 10 to 40 parts by weight of fiber, (d) 0.5 to 0.5 parts of mica surface-treated with an aminosilane compound
10 parts by weight, and (e) 1 to 10 parts by weight of wollastonite surface-treated with an aminosilane compound, and the total amount of resin components is 50 to 85 parts by weight of the total amount of the composition.
A reinforced polypropylene composition obtained by melt-mixing a mixture in which the total amount of inorganic filler components is 15 to 50% by weight based on the total amount of the composition.