JPH1036598A - Xonotlite-reinforced polypropylene composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a xonotlite-reinforced polypropylene composition comprising a fibrous xonotlite and a modified polypropylene, excellent in balance of physical properties between rigidity, mechanical strength and heat resistance and impact resistance and capable of suitably using as a material for fields such as automobiles, electric and electronics and precision machines. SOLUTION: This composition comprises (A) a polypropylene obtained by modifying 100 pts.wt. crystalline polypropylene with 0.01-0.5 pts.wt. unsaturated carboxylic acid and (B) a fibrous xonotlite, having >=21m BET specific surface area by nitrogen absorption, whose surface is treated with an aminosilane coupling agent in an amount of 0.1-3 pts.wt. based on 100 pts.wt. fibrous xonotlite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a polypropylene composition reinforced with fibrous zonotolite. The molded product obtained by using the present composition has excellent balance between rigidity, mechanical strength, heat resistance and impact resistance, and also has good appearance of the molded product, such as automobiles, electric / electronics, and precision machinery. Can be suitably used as a material in the field of

[0002]

2. Description of the Related Art The rigidity, strength, heat resistance,
It is already known to incorporate fibrous zonotolite therein for the purpose of improving dimensional stability, molding shrinkage and the like (see Japanese Patent Application Laid-Open No. 7-216133). Furthermore, in order to further enhance the compounding effect, the surface of the fibrous zonotolite is treated with a silane coupling agent, and
There is also a method using a modified polypropylene as the polypropylene, which is disclosed in the above-mentioned publication.
However, the above method certainly improves the strength and heat resistance as compared with a composition composed of, for example, unmodified polypropylene and a nonionic surfactant-treated fibrous zonotolite. Causes a decrease in

[0003] In a polypropylene composition containing an inorganic filler, as a method for obtaining physical properties balanced with strength, heat resistance, and impact resistance, the surface of the inorganic filler is treated with an aminosilane coupling agent. Techniques using modified polypropylene modified with acrylic acid, maleic anhydride, etc. as propylene are known as talc (see AMAdur & SRFlynn, SPE ANTEC, 508 ('87)), mica (AMAdur, RCConstable & JAHum).
enik, SPE ANTEC, 1474 ('88) etc.) and glass fiber (RCConstable, JAHumenik & AMAdur, SPE AN
TEC, 1389 ('89), RCConstable & AMAdur, SPE AN
TEC, 1892 ('91) and J. Denault et al, SPE ANTEC,
788 ('92) etc.).

[0004]

However, in the case of the polypropylene composition containing the above-mentioned inorganic filler, when the modifying amount of acrylic acid or maleic anhydride as a modifying agent is considerably large (for example, 0% with respect to the amount of polypropylene). .6
(Approximately 1.2% by weight), it is clear from the above-mentioned literature that improvement in impact strength of the composition cannot be expected. Accordingly, an object of the present invention is to provide a zonotolite-reinforced polypropylene composition comprising a fibrous zonotolite and a modified polypropylene, in which rigidity, mechanical strength, heat resistance, and impact resistance were not solved by the prior art. To provide.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, they have been achieved by using polypropylene having a specific property and fibrous zonotolite. We have found that we have completed the present invention. That is, the present invention provides a zonotolite-reinforced polypropylene composition comprising a polypropylene modified with an extremely small amount of unsaturated carboxylic acid, and a fibrous zonotolite having a specific specific surface area and surface-treated with a specific amount of an aminosilane coupling agent. It is about things.

[0006] More specifically, the first aspect of the present invention.
The invention of (A) is that the modified amount is crystalline polypropylene 100
0.01 to 0.5 parts by weight per part by weight of a polypropylene modified with an unsaturated carboxylic acid, and (B)
The BET specific surface area by nitrogen adsorption is 21 m ² / g or more, and the surface thereof is made of fibrous zonotolite treated with 0.1 to 3 parts by weight of aminosilane coupling agent per 100 parts by weight of fibrous zonotolite. Can be achieved by providing a zonotolite-reinforced polypropylene composition as follows.

In a second aspect of the present invention, the fibrous zonotolite (B) has a particle size of 0.1 μm ≦ D <0.5 μm, 1 μm
m ≦ L <5 μm and 10 ≦ L / D <20 (where D
And L respectively indicate the average fiber diameter and average fiber length of the fibrous zonotolite (B)), and are achieved by providing the zonotolite-reinforced polypropylene composition according to the first invention. it can. Further, a third invention according to the present invention provides the zonotolite-reinforced polypropylene composition according to the first or second invention, wherein the unsaturated carboxylic acid is maleic anhydride, and a fourth invention according to the present invention. The invention according to the first, wherein the aminosilane coupling agent is γ-aminopropyltriethoxysilane.
This can be achieved by providing the zonotolite-reinforced polypropylene composition according to the second or third invention, respectively.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The fibrous zonotolite (B) described in the present invention refers to a needle-like crystalline substance of zonotolite (having a chemical formula: Ca ₆ Si ₆ O ₁₇ (OH) ₂ , a chemical formula: 6CaO.6SiO ₂ .H ₂ O). In the present invention, the value of the specific surface area is very important, and is 21 m ² / g or more, preferably 30 m ² / g or more (however, measured by the BET method by nitrogen adsorption).
Must. In the case of a fibrous zonotolite having a value of less than 30 m ² / g, the wettability with the polypropylene (A) modified with an unsaturated carboxylic acid tends to be poor, and in particular, a fiber having a specific surface area of less than 21 m ² / g. In the case of zonotorite, the above-mentioned object of the present invention cannot be achieved because the tendency is remarkable.

Furthermore, in the present invention, the fiber shape of the fibrous zonotolite (B) is preferably such that the average fiber length (L) is 1 μm ≦ L <5 μm and the average fiber diameter (D) is 0.1 μm.
1 μm ≦ D <0.5 μm, and the aspect ratio (L /
Those in which D) simultaneously satisfies the condition of 10 ≦ L / D <20 can be suitably used. When D is less than 0.1 μm or L is 5 μm or more, fibrous zonotolite (B) is
When mixing and kneading with a polypropylene (A) modified with an unsaturated carboxylic acid, the fibrous zonotolite (B) may be broken, and if D is 0.5 μm or more or L is less than 1 μm, The effect of improving the mechanical strength of the obtained zonotolite-reinforced polypropylene composition by the fibrous zonotolite (B) may not be sufficient.
When the L / D is less than 10, the obtained zonotolite-reinforced polypropylene composition may not have sufficient mechanical strength, and the L / D may be less than 20.
In the case described above, the bulk specific gravity of the fibrous zonotolite (B) becomes too small, so that kneading may be difficult at the time of producing a zonotolite-reinforced polypropylene composition or the like.

As described in detail below, the fibrous zonotolite (B) of the present invention having the above-mentioned specific properties can be produced, for example, by the production method described in JP-A-6-128412, It is manufactured by blending a raw material and a siliceous raw material at a specific ratio and performing a hydrothermal synthesis reaction. Examples of the calcareous raw materials include quick lime, slaked lime, carbide slag, and the like, and those containing few impurities such as magnesium oxide are preferable. In addition, siliceous raw materials include silica stone,
Pulverized silica sand and quartz, silicic acid, silicic anhydride, silica gel, diatomaceous earth, terra alba and ferrosilicon dust, etc., and these siliceous raw materials are fine powders having few impurities and an average particle diameter of 10 μm or less. desirable.
The mixing ratio (Ca / Si ratio) of these two is slightly smaller than the theoretical equivalent, and is preferably 0.8 to 0.99. The ratio of water to be mixed is 5 to 40 times, preferably 8 to 30 times, the total weight of the calcareous raw material and the siliceous raw material.
It is desirable to be twice.

In the hydrothermal synthesis reaction, for example, the calcareous raw material, the siliceous raw material and water in the above-mentioned predetermined ratio are charged into an autoclave, and the mixture is usually stirred at 180 to 240 ° C. for 1 hour.
It may take up to 8 hours. In this case, a predetermined ratio of the calcareous raw material, the siliceous raw material and water may be previously mixed in a slurry state and then charged into the autoclave. The reaction temperature and the reaction time in the hydrothermal synthesis reaction are important factors. If the reaction temperature and the reaction time are out of the above ranges, the fibrous zonotolite having the specific specific surface area used in the present invention as described above cannot be obtained.

In the present invention, the fibrous zonotolite obtained by the above-mentioned production method further has an aminosilane surface in order to further improve the reinforcing effect on the polypropylene (A) modified with an unsaturated carboxylic acid described later. Treated with a coupling agent. That is, the aminosilane coupling agent chemically bonds the fibrous zonotolite with the matrix resin, that is, the polypropylene (A) modified with the unsaturated carboxylic acid, and further enhances its reinforcing effect, that is, further increases the mechanical strength. Things. As the aminosilane coupling agent, γ-
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-
Aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-β
Examples of a silane coupling agent having a terminal amino group at an organic functional group that reacts with a polymer compound such as (aminopropyl) γ-aminopropylmethyldimethoxysilane, γ-dibutylaminopropyltrimethoxysilane, and γ-ureidopropyltriethoxysilane it can. Among them, γ-aminopropyltriethoxysilane is mentioned as a typical one.

The aminosilane coupling agent is added in an amount of 0.1 to 3 parts by weight, preferably 0.5 to 1 part by weight, based on 100 parts by weight (based on dry matter) of the fibrous zonotolite.
Should be parts by weight. If the added amount is less than 0.1 part by weight, the above-mentioned strength improving effect is not sufficient, and if the added amount exceeds 3 parts by weight, the above-mentioned strength improving effect hardly increases even if the added amount is increased. . In addition, the addition amount is 0.1.
When the amount is in the range of 1 to 0.5 part by weight, the above-mentioned strength improving effect may not be sufficient, and when the amount is in the range of 1 to 3 parts by weight, the above-mentioned strength improving effect tends to be undesirably increased.

In the present invention, as described above, the fibrous zonotolite slurry obtained by the hydrothermal synthesis reaction is extracted from the autoclave, and the surface treatment of the fibrous zonotolite is performed with an aminosilane coupling agent. The surface treatment method is not particularly limited. For example, the aminosilane coupling agent is added to the fibrous zonotolite slurry as it is, or after adding an appropriate amount of water, and mixed and stirred in a slurry state using an appropriate device. .
Subsequently, excess water is filtered and separated by a centrifugal dehydrator or a filter press to obtain a cake-like fibrous zonotolite. This surface treatment may be performed by a so-called dry treatment method in which the above fibrous zonotolite slurry is dried and then used with an aminosilane coupling agent dissolved in a small amount of water or a solvent.

Next, the cake-like fibrous zonotolite to which the aminosilane coupling agent is attached as described above is dried and heat-treated to obtain the fibrous zonotolite (B) used in the present invention. Drying is performed using a known dryer such as a hot air circulation dryer or an infrared heating dryer.
It is preferable to carry out the reaction at a temperature of 0 to 150 ° C. for 20 to 30 hours until the water content of the fibrous zonotolite becomes 1% by weight or less. In addition, the heat treatment is performed in the range of 100 to 150.
It is preferred to carry out the drying following the drying of the water under heating at 20C for 20-30 hours. Furthermore, the fibrous zonotolite (B) used in the present invention can also be granulated for the purpose of easily mixing and kneading with the modified polypropylene (A) described later. In this case, the above-mentioned drying and heat treatment may be performed after the cake-like fibrous zonotolite to which the aminosilane coupling agent is attached is formed into granules having a diameter of 1 to 8 mm by a granulator.

In the present invention, a polypropylene obtained by modifying a crystalline polypropylene with an unsaturated carboxylic acid is used as the polypropylene (A). Here, the polypropylene obtained by modifying the crystalline polypropylene with an unsaturated carboxylic acid refers to a modified polypropylene obtained by the modification or a mixture of the modified polypropylene and an unmodified polypropylene. Examples of the crystalline polypropylene used in the production of the modified polypropylene include, in addition to crystalline homopolypropylene, propylene and other α-olefins, for example, ethylene, butene-1, pentene-1, hexene-
Crystalline random or block copolymers with α-olefins having 2 to 8 carbon atoms, such as 1, heptene-1 and octene-1 can be used. Among them, a crystalline ethylene / propylene block copolymer is particularly preferable.

The most preferred crystalline ethylene / propylene block copolymer has an ethylene content of 0.5 to 1
0% by weight, preferably 3 to 8% by weight, and the boiling n-heptane insoluble content of the polypropylene component is 95% by weight or more;
It is preferably at least 97% by weight and has a melt flow index (measured at 230 ° C) of 1 to 70 g / 10
Min, preferably about 1 to 30 g / 10 min. In the use of the above-mentioned crystalline ethylene / propylene block copolymer, if the ethylene content is less than 0.5% by weight, the impact resistance of the zonotolite-reinforced polypropylene composition is insufficient. Either case is not preferable because the stiffness and heat resistance of the reinforced polypropylene composition become insufficient. If the amount of the boiling n-heptane insoluble component indicating the degree of crystallinity of the polypropylene component is less than 95% by weight, the crystalline ethylene / propylene block copolymer has low crystallinity and is unsuitable for physical properties. Is not preferred. Further, when the melt flow index (measured at 230 ° C.) is less than 1 g / 10 minutes, the moldability of the zonotolite-reinforced polypropylene composition is reduced, which is not practically preferable. On the other hand, the value is 70 g /
If the time is longer than 10 minutes, the zonotlite-reinforced polypropylene composition is inferior in physical properties and unsuitable for practical use. In order to reliably prevent the occurrence of the above-mentioned undesirable phenomenon, the crystalline ethylene
The ethylene content, the boiling n-heptane insoluble content of the polypropylene component and the melt flow index (measured at 230 ° C.) of the propylene block copolymer should each be within the above-mentioned preferred ranges.

As the modified polypropylene modified with an unsaturated carboxylic acid in the present invention, known ones can be used, and the production method thereof is also already known (see, for example, Japanese Patent Publication No. Sho 51-10265). .

Examples of the above unsaturated carboxylic acids include acrylic acid, methacrylic acid, methyl methacrylic acid, crotonic acid, isocrotonic acid, furic acid, pentenoic acid, angelic acid, maleic acid, fumaric acid, tetrahydrophthalic acid,
Α, β-unsaturated carboxylic acids such as itaconic acid, citraconic acid, endocis-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (trade name: nadic acid), citric acid and aconitic acid Acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, endocis-bicyclo [2,2,1] hept-5
And unsaturated carboxylic anhydrides such as -ene-2,3-dicarboxylic anhydride (trade name: nadic anhydride) and aconitic anhydride. Among these, maleic anhydride is the most representative.

The amount of the unsaturated carboxylic acid used is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the crystalline polypropylene. If the amount is less than 0.1 part by weight based on 100 parts by weight of the crystalline polypropylene, the modifying effect is not sufficient, and if it exceeds 5 parts by weight, the modification efficiency (ie, the reaction of unsaturated carboxylic acid) In any case, unreacted monomers increase as the ratio decreases.

As the initiator for the modification reaction of the crystalline polypropylene with the unsaturated carboxylic acid, an organic peroxide is most generally used. As a representative example, t
-Butyl peroxybenzoate, 2,5-dimethyl-
2,5-di (benzoylperoxy) hexane, 2,5
-Dimethyl-2,5-di (benzoylperoxy) hexine-3, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) Hexane,
2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, t-butylperoxyacetate,
And methyl ethyl ketone peroxide. The addition amount of the reaction initiator is the same as that of the crystalline polypropylene 100.
It is desirable that the amount be 0.05 to 1 part by weight based on part by weight. If the addition amount is less than 0.05 part by weight based on 100 parts by weight of the crystalline polypropylene, the modification efficiency cannot be sufficiently expected, which is not preferable. On the other hand, if it exceeds 1 part by weight, deterioration and coloring of the crystalline polypropylene become remarkable, which is not preferable.

The modified polypropylene of the present invention is prepared by mixing the crystalline polypropylene, the unsaturated carboxylic acid, and the reaction initiator at the above-mentioned predetermined ratios, and using an extruder, a Banbury mixer, or the like, to obtain the modified polypropylene. A method of melt-kneading at a temperature of about 1 to 20 minutes, or after heating and dissolving the predetermined amount of crystalline polypropylene in toluene or xylene in a reaction vessel, the unsaturated carboxylic acid and the reaction initiator Are added at predetermined ratios, and the reaction is performed under stirring. In particular, the former method is simple and suitable as an industrial process. The modified polypropylene thus obtained has a monomer modification rate (that is, a reaction rate of the unsaturated carboxylic acid) of 0.05 to 5 parts by weight, based on 100 parts by weight of the crystalline polypropylene, and a melt flow index (at 230 ° C). Measurement) is about 1 to 100 g / 10 minutes.

In the present invention, as described above, the modified polypropylene obtained as described above can be used alone as the polypropylene (A), but it may be used as a mixture with the unmodified polypropylene. In this case, the same unmodified polypropylene as the crystalline polypropylene used in the production of the above-mentioned modified polypropylene can be used.

The most important constituent element of the present invention is the amount of the unsaturated carboxylic acid modified with respect to the entire polypropylene (A). In the present invention, this value is 0.01 to 0.5 with respect to 100 parts by weight of the crystalline polypropylene.
It is necessary that the amount be part by weight, preferably 0.01 to 0.3 part by weight. That is, when the modified polypropylene is used alone as the polypropylene (A), the value is 0.01 to 0.5 part by weight, preferably 0.01 to 0.5 part by weight, per 100 parts by weight of the crystalline polypropylene constituting the modified polypropylene. To 0.3 parts by weight, and when a mixture of the modified polypropylene and the unmodified polypropylene is used as the polypropylene (A), the total amount of the modified polypropylene and the unmodified polypropylene is 100 parts by weight. It is necessary to be 0.01 to 0.5 part by weight, preferably 0.01 to 0.3 part by weight. If this value is less than 0.01 parts by weight, the rigidity, mechanical strength, heat resistance and the like of the molded article obtained from the zonotlite reinforced polypropylene composition are low, and the effect of the present invention is not sufficiently exhibited. However, when this value is more than 0.5 part by weight, the impact resistance of the molded article obtained from the zonotolite-reinforced polypropylene composition is rather lowered, which is not preferable. Therefore, it is inevitable that the amount of modification of the unsaturated carboxylic acid falls within the above range. The amount of modification of the unsaturated carboxylic acid should be within the above-mentioned preferred range in order to surely suppress the occurrence of the above-mentioned undesirable phenomena. Thus, it is a feature of the present invention that the amount of modification of the unsaturated carboxylic acid is much smaller than conventionally known.

Further, as long as the effects of the present invention are not impaired, the zonotrite-reinforced polypropylene composition comprising the polypropylene (A) and the fibrous zonotolite (B) is usually blended with a resin in order to improve properties and production. Various auxiliary materials to be used, that is, heat stabilizers, light stabilizers, antioxidants, antistatic agents, lubricants, nucleating agents, mold release agents, impact modifiers, plasticizers, crosslinking agents, foaming agents, flame retardants In addition to additives and modifiers such as flame-retardant aids, pigments, dyes and fragrances, fillers and reinforcing materials can also be added. As the filler or reinforcing material, for example, wood flour as an organic substance, pulp, and iron as an inorganic substance, whisker such as copper, gold, silver, aluminum, flakes, fiber or powdered metal, carbon black, graphite, Carbon fiber, activated carbon, carbon materials such as hollow spheres, silica, alumina, silica-alumina, titanium oxide, iron oxide, zinc oxide, magnesia, calcia, potassium titanate, various ferrites, basic magnesium sulfate, basic magnesium carbonate Oxides including other complex oxides, silicates such as talc, clay, mica, asbestos, rock wool and zinc silicate, hydroxides, carbonates, sulfates, phosphates, borates of various metals, Borosilicate, aluminosilicate, titanate, basic sulfate,
Glass materials such as glass fiber, glass hollow spheres, glass flakes, etc., such as basic carbonates and other basic salts;
Ceramics such as silicon carbide, silicon nitride, aluminum nitride, mullite and cordierite, and waste such as fly ash and microsilica are included.

In the present invention, the content of the fibrous zonotolite (B) in the zonotolite-reinforced polypropylene composition comprising the polypropylene (A) and the fibrous zonotolite (B) is preferably 5 to 65% by weight, and more preferably 5 to 65% by weight. Is preferably 10 to 50% by weight. The content of the fibrous zonotolite (B) is 5% by weight.
If the amount is less than the above, it is not preferable because the mechanical strength, heat resistance, molding shrinkage, etc. of the obtained zonotolite-reinforced polypropylene composition are not improved. On the other hand, when the content is more than 65% by weight, the melt flowability of the obtained zonotrite-reinforced polypropylene composition decreases, and molding becomes difficult, and the appearance of a molded product obtained from the zonotolite-reinforced polypropylene composition deteriorates, which is preferable. Absent. In addition, the content of the fibrous zonotolite (B) is 5% by weight or more and 10% by weight.
If it is less than 50% by weight or more than 50% by weight and less than 65% by weight, the above-mentioned undesirable phenomena may occur.

The zonotolite-reinforced polypropylene composition comprising the polypropylene (A) and the fibrous zonotolite (B) is produced by a known method. That is, generally, the above-mentioned predetermined amounts of the polypropylene (A) and the fibrous zonotolite (B) are melt-kneaded using a kneading machine to obtain the zonotolite-reinforced polypropylene composition of the present invention. At this time, the melt-kneading temperature is 170 to 250 ° C, preferably 190 to 230 ° C.
C. is desirable. If the melt-kneading temperature is lower than 170 ° C., in the kneader, the melt viscosity of the polypropylene becomes too high, and a portion having a temperature lower than the melting point of the polypropylene occurs. May cause On the other hand, if the melt-kneading temperature is higher than 250 ° C., thermal decomposition or thermal degradation of the polypropylene occurs, which results in discoloration or deterioration in physical properties of the obtained zonotolite-reinforced polypropylene composition. In order to reliably prevent the occurrence of these undesired phenomena related to the melt-kneading temperature, the melt-kneading temperature should be within the above-mentioned preferable range.

Examples of the kneading machine include extruders such as a single screw extruder and a twin screw extruder, a twin screw continuous mixer, a Banbury mixer, a super mixer, a mixing roll,
Kneaders, Brabender plastographs and the like can be mentioned, and the zonotolite-reinforced polypropylene composition is
Generally, it is usually obtained as a pellet. As the kneader, an extruder is preferable among the above, and a twin screw extruder is particularly preferable.

Further, the addition and mixing order of these components at the time of melt-kneading the polypropylene (A) and the fibrous zonotolite (B) can be arbitrarily selected. For example, prior to melt kneading, the fibrous zonotolite (B) may be premixed with the polypropylene (A) using a Henschel mixer, a ribbon blender, a tumbler blender or the like, and the mixture may be supplied to a hopper of an extruder. Alternatively, only the polypropylene (A) may be supplied to the hopper of the extruder, and the fibrous zonotolite (B) may be supplied in the middle of the extruder. In producing the zonotolite-reinforced polypropylene composition, from the middle of the hopper or the extruder of the extruder,
If necessary, the various auxiliary materials described above can be added at the same time.

The zonotolite-reinforced polypropylene composition of the present invention thus obtained is obtained by injection molding,
It is molded into a desired shape by various known molding methods such as extrusion molding, compression molding, and hollow molding.

[0031]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited by these Examples and Comparative Examples unless it exceeds the gist thereof. Absent.

The physical properties of molded articles obtained from the modified polypropylene and the zonotolite-reinforced polypropylene compositions described in the following Examples and Comparative Examples were evaluated according to the following methods. (1) Determination of maleic anhydride reaction rate of modified polypropylene A predetermined amount of a sample (modified polypropylene) was dissolved in p-xylene, reprecipitated in acetone, filtered and dried, and p
-Dissolved in xylene. Next, K
OH was added, and titration was performed with HCl using thymol blue as an indicator.

(2) Melt Flow Index of Molded Product Measured at 230 ° C. according to ASTM D1238 using a melt indexer.

(3) Bending properties of molded articles Measured using Tensilon UTM-5T manufactured by Orientec Co., Ltd. After molding the desired zonotlite-reinforced polypropylene composition, the composition is heated to 23 ° C. and 50% relative humidity (hereinafter referred to as “50”).
% RH ") for 48 hours. And
Measurement of flexural properties (flexural strength and flexural modulus) was performed using AS
Performed at 23 ° C. and 50% RH according to TM D790.

(4) Tensile Properties of Molded Article After molding a desired zonotolite-reinforced polypropylene composition, the same condition as in the above item (3) was adjusted. continue,
Tensile properties (tensile strength and tensile modulus) were measured at 23 ° C. and 50% RH according to ASTM D638 using the same apparatus as in the above section (3).

(5) Deflection temperature under load of molded article Measured using a load deflection tester manufactured by Toyo Seiki Co., Ltd. According to ASTM D648, a stress of 0.45 MPa
Below.

(6) Izod Impact Strength of Molded Product The Izod impact strength was measured using an Izod impact tester manufactured by Toyo Seiki Co., Ltd. The notched Izod impact strength was determined in accordance with ASTM D256 under the same temperature and humidity conditions as in the above item (3), using the test pieces whose condition was adjusted in the same manner as in the above item (3).

Reference Example 1 (Production of fibrous zonotolite) As a calcareous raw material, quick lime (a product of Calceed Co., Ltd., Ca
430 g of siliceous raw material for agricultural use (a product of Japan General Co., Ltd., Blaine specific surface area: 7,000 cm ² / g, SiO ₂ purity: 97%) 4
70 g and 18 liters of tap water were charged into a 30 liter SUS316 autoclave equipped with a stirrer. Then, while stirring at a rotation speed of a stirrer of 80 rpm, the temperature is raised to a holding temperature of 220 ° C. at a rate of 2 ° C./min, and the holding temperature is maintained at 220 ° C. for 5 hours to perform a hydrothermal synthesis reaction. The mixture was allowed to cool for 10 hours or more to obtain a fibrous zonotolite slurry. When the X-ray diffraction of this slurry was measured, only zonotolite was identified.

Subsequently, about liters of tap water and about 18 liters of tap water and an aminosilane coupling agent (γ-aminopropyltriethoxysilane, a product of Nippon Unicar Co., Ltd., trade name: A) were added to 920 g (solid basis) of the fibrous zonotolite slurry.
9100 g (1 part by weight based on 100 parts by weight of the solid content of fibrous zonotolite), and subjected to surface treatment while dispersing with a homogenizer. The slurry was dehydrated with a nutsche to form a cake, and then dried at about 100 ° C.
By performing a heat treatment at 20 ° C. for 20 minutes, a fibrous zonotolite whose surface was treated was obtained. The BET specific surface area of the fibrous zonotolite was measured by nitrogen adsorption, and the average fiber length and the average fiber diameter were measured by a scanning electron micrograph. As a result, 39 m ² / g,
3 μm and 0.2 μm (hence the aspect ratio:
15).

Example 1 Polypropylene resin (trade name: UB, manufactured by Ube Industries, Ltd.)
E Polypropylene B101H, hereinafter abbreviated as “PP”) 100
0.2 part by weight of maleic anhydride and 0.2 part by weight of t-butyl peroxybenzoate were added to the mixture,
kneaded at 230 ° C using a single-screw extruder of
I got This modified PP has a maleic anhydride reaction rate of 0.
18% by weight, melt flow index 35 g / 10
Minutes.

Therefore, using a co-rotating twin-screw extruder with a cylinder diameter of φ30 mm (model: PCM30, manufactured by Ikegai Iron Works Co., Ltd.), 230 ° C. (however, the temperature of the nozzle portion is used, the same applies hereinafter) In the above, 24 parts by weight of the modified PP, 56 parts by weight of a crystalline ethylene / propylene block copolymer (trade name: UBE Polypro J709HK, manufactured by Ube Industries, Ltd.) and 20 parts by weight of the fibrous zonotolite obtained in Reference Example 1 were added. The mixture was melt-kneaded to prepare pellets of a zonotlite-reinforced polypropylene composition having a maleic anhydride modification amount of 0.043 parts by weight based on a total of 100 parts by weight of the modified PP and the crystalline ethylene / propylene block copolymer. However, at this time, the fibrous zonotolite was supplied from the first vent of the extruder using a screw feeder, and deaeration was performed from the second vent of the extruder. next,
Using an injection molding machine (manufactured by Japan Steel Works, Ltd., model: N100), the above pellets are injected at 230 ° C. cylinder temperature (however, the same as the temperature of the nozzle head, the same applies hereinafter) and a mold temperature of 80 ° C. It was molded to produce a physical property test piece. Table 1 shows the results of the physical property tests of the obtained materials.

Examples 2 to 5 and Comparative Examples 1 and 2 The proportions of the modified PP and the crystalline ethylene / propylene block copolymer were 24 parts by weight and 56 parts by weight, respectively.
Except that the parts were changed to parts by weight and as shown in Table 1, the same operation as in Example 1 was performed to prepare physical property test pieces of the zonotolite-reinforced polypropylene composition. Table 1 shows the results of the physical property tests of the obtained materials. Comparative Example 1
In the cases of and 2, the obtained materials, that is, the deflection temperatures under load of the molded articles of the zonotolite-reinforced polypropylene composition were 141 ° C. and 140 ° C., respectively, and were inferior in heat resistance.

Example 6 The procedure of Example 1 was repeated, except that the amount of maleic anhydride was changed to 0.2 part by weight to 0.6 part by weight.
A modified PP (reaction rate of maleic anhydride: 0.55% by weight, melt flow index: 30 g / 10 minutes) was obtained. Therefore, modified PP (maleic anhydride conversion: 0.18% by weight, melt flow index: 35 g / 10 min) 56
In place of parts by weight, the modified PP (maleic anhydride conversion: 0.55% by weight, melt flow index: 30)
g / 10 min) Example 4 except that 56 parts by weight were used.
By performing exactly the same operations as in the above, physical property test pieces of the zonotolite-reinforced polypropylene composition were prepared. Table 1 shows the results of the physical property tests of the obtained materials.

Comparative Example 3 The mixing ratio of the modified PP (maleic anhydride conversion: 0.55% by weight, melt flow index: 30 g / 10 minutes) was changed to 56 parts by weight to 80 parts by weight, and
Example 6 was repeated except that the blending ratio of the crystalline ethylene / propylene block copolymer was changed to 24 parts by weight to 0 parts by weight, that is, the crystalline ethylene / propylene block copolymer was not blended. Exactly the same operation was performed to prepare a physical property test piece of the zonotolite-reinforced polypropylene composition. Table 1 shows the results of the physical property tests of the obtained materials.
Shown in The Izod impact strength of the obtained material, that is, the molded article of the zonotolite-reinforced polypropylene composition is 3
It was 0 J / m and was inferior in impact resistance.

[0045]

[Table 1]

[0046]

As is clear from the examples and comparative examples described above, the zonotolite-reinforced polypropylene composition provided by the present invention is compared with a conventionally known composition comprising fibrous zonotolite and polypropylene. ,
The physical properties of rigidity, mechanical strength, heat resistance and impact resistance are well balanced. Therefore, it can be used as a material in fields such as automobiles, electric / electronics, and precision machinery.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Akira Masuda, 1985 Kobe, Ogushi, Ube City, Yamaguchi Prefecture Inside Ube Chemical Industry Co., Ltd.

Claims (4)

[Claims] (A) a crystalline polypropylene 1 having a modified amount of 1
(B) (1) a BET specific surface area by nitrogen adsorption of 21 m ² which is 0.01 to 0.5 part by weight to 100 parts by weight and modified with an unsaturated carboxylic acid;
/ G or more, and (2) a zonotolite-reinforced polypropylene composition characterized in that its surface comprises fibrous zonotolite treated with 0.1 to 3 parts by weight of an aminosilane coupling agent per 100 parts by weight of fibrous zonotolite. Stuff. 2. The fibrous zonotolite (B) comprises (1)
0.1 μm ≦ D <0.5 μm, (2) 1 μm ≦ L <5 μ
m and (3) 10 ≦ L / D <20 (where D and L respectively represent the average fiber diameter and average fiber length of the fibrous zonotolite (B)). 2. The zonotolite-reinforced polypropylene composition according to 1. 3. The zonotolite-reinforced polypropylene composition according to claim 1, wherein the unsaturated carboxylic acid is maleic anhydride. 4. The zonotolite-reinforced polypropylene composition according to claim 1, wherein the aminosilane coupling agent is γ-aminopropyltriethoxysilane.