JP2018135459A - Talc master batch, and method for producing vehicular resin molding using the talc master batch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a talc master batch that can suppress blocking during preliminary dry effectively than before, and a method for producing a vehicular resin molding using the talc master batch.SOLUTION: As an elastomer component of talc MB, used is an elastomer component with a high complete melt temperature, and a compounding ratio of the elastomer component is reduced.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a talc masterbatch and a method for producing a resin molded product for a vehicle using the talc masterbatch.

  In recent years, in the automobile industry, the need for resin vehicle parts is increasing from the viewpoint of weight reduction of the vehicle body.

  As a material for such resin-made vehicle parts, polypropylene resin that is relatively inexpensive and excellent in balance of various properties is widely used. For example, talc is used to improve rigidity and heat resistance with respect to polypropylene resin. An added talc-containing polypropylene material or the like is used (for example, see Patent Document 1).

  The high-concentration talc masterbatch described in Patent Document 1 is a blend of a crystalline polypropylene resin having a specific fluidity, talc having a specific particle size and a metal soap in a specific ratio to an elastomer having a specific fluidity. Therefore, it is described that it has high heat resistance, has excellent workability without causing a problem in the pellet shape in preliminary drying, exhibits a good molded appearance, and can efficiently control the shrinkage rate.

JP 2002-0669204 A

  However, in the thing of patent document 1, when pre-drying a high concentration talc masterbatch, there still exists a tendency for pellet blocking to occur, and there was room for improvement from the viewpoint of blocking inhibition.

  Therefore, an object of the present invention is to provide a talc master batch that can further suppress blocking during preliminary drying. Moreover, it aims at providing the manufacturing method of the resin molded product for vehicles using such a talc masterbatch.

  In order to achieve the above object, in the present invention, an elastomer component having a high complete melting temperature is used for the elastomer component of the talc masterbatch, and the blending ratio of the elastomer component is reduced.

That is, the talc masterbatch according to the first technique disclosed herein is a talc masterbatch obtained by kneading and granulating the following components A to D. That is,
Component A: Elastomer having a complete melting temperature of 80 ° C. or more: 5% by mass or more and less than 26.5% by mass Component B: Crystalline polypropylene resin: more than 20% by mass and 45% by mass or less Component C: Talc: 46% by mass or more and 70% by mass % Or less Component D; Additive: 0.01 mass part or more and 5 mass parts or less (mass of component B is 100 mass parts (provided that the total of component A, component B, and component C is 100 mass%))
Talc masterbatch is highly hygroscopic and needs to be pre-dried before molding. In this preliminary drying step, the phenomenon in which the pellets of the talc master batch are bonded and aggregated to form a block is called blocking. When blocking of the talc masterbatch occurs, for example, the talc masterbatch is clogged in the pipe on the way, making it difficult to quickly and continuously supply the injection molding machine.

  Blocking occurs, for example, when the elastomer component contained in the talc masterbatch melts during pre-drying. Therefore, blocking can be suppressed by suppressing melting of the elastomer component during preliminary drying.

  According to the first technique, an elastomer having a high complete melting temperature is used as the component A, and by suppressing the blending ratio of the component A within a predetermined range, the melting of the elastomer component at the time of preliminary drying is suppressed, Blocking can be suppressed.

  In the second technique, in the first technique, the blending ratio of the component A is 21% by mass or more and 26% by mass or less.

  According to the second technique, by setting the blending ratio of the elastomer component within the above range, it is possible to effectively suppress melting of the elastomer component during preliminary drying while ensuring good dispersibility of talc in the molded product. Thus, blocking of the talc master batch can be suppressed.

  Further, in the third technique, in the first or second technique, the blending ratio of the component B is 26.7% by mass or more and 33% by mass or less, and the blending ratio of the component C is 46% by mass or more. It is less than 50% by mass.

  According to the 3rd technique, blocking of a talc masterbatch can be effectively suppressed by making the compounding ratio of a crystalline polypropylene resin component and a talc component into the said range. Further, in the molded product, a sufficient amount of talc can be secured and the dispersibility of talc can be improved, so that a molded product having high rigidity and excellent impact resistance can be obtained.

  The fourth technique is the following formula (1) when drying in a pressurized state of 20 kg load at 70 ° C. for 2.5 hours in any one of the first to third techniques. ) Is a blocking rate P (%) of 8% or less.

P = X / Y × 100 (1)
(However, in formula (1), X represents the mass of the agglomerated portion.)
According to the fourth technique, blocking of the talc masterbatch is effectively suppressed, and in the manufacturing process of the molded product, continuous supply to the injection molding machine is possible, which is highly rigid and excellent in impact resistance. The molded product can be efficiently manufactured.

  The method for producing a resin molded product for a vehicle according to the fifth technology is a method for producing a resin molded product for a vehicle using any one of the talc master batches of the first to fourth technologies, and the component E A drying step of drying 38 parts by mass or more and 65 parts by mass or less of the talc masterbatch at a temperature higher than 60 ° C. and lower than 80 ° C. for 1.5 hours or more, the component E dried in the drying step, and a component F for dilution A melting step of heating and melting polypropylene resin in an amount of 35 parts by mass to 62 parts by mass to obtain a molten plastic, and a molding step of injecting the molten plastic into a mold to obtain an injection molded product are provided. . However, the sum total of the component E and the component F shall be 100 mass parts.

  According to the fifth technique, by setting the blending ratio of the component E and the component F within the above range, it is possible to manufacture a resin molded product for a vehicle that is highly rigid and excellent in impact resistance. In addition, by setting the drying temperature and time in the drying process of the talc masterbatch to the above range, the moisture content in the talc masterbatch is suppressed while preventing the elastomer component in the talc masterbatch from being melted and blocking the pellets. It can be effectively reduced. Thus, the vehicle resin molded product can be continuously manufactured.

  As described above, according to the present invention, an elastomer having a high complete melting temperature is used as the component A, and the mixing ratio of the component A is suppressed within a predetermined range, thereby suppressing the melting of the elastomer component during preliminary drying. Can be blocked.

FIG. 1 is a graph showing a DSC measurement result of an elastomer. FIG. 2 is a diagram for explaining a method of a talc MB blocking evaluation test. FIG. 3 is a diagram for explaining a method of a talc MB blocking evaluation test. FIG. 4 is a diagram showing the results of a blocking evaluation test when the blending ratio of EBR in talc MB is 33%, that is, the blocking rate is 90%. FIG. 5 is a diagram showing the results of a blocking evaluation test when the blending ratio of EOR in talc MB is 25%, that is, the blocking rate is 5%. FIG. 6 is a flowchart for explaining a method of manufacturing a molded product. FIG. 7 is a graph showing the change over time in the moisture content when talc MB is dried at various temperatures. FIG. 8 is a graph showing the change in blocking rate relative to the blending ratio of the elastomer for talc MB having a blending ratio of talc of 46% by mass. FIG. 9 is a graph showing the change in blocking rate with respect to the blending ratio of crystalline PP for talc MB with a blending ratio of talc of 46.8% by mass.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

(Embodiment 1)
<Talc master batch>
When talc is mixed with a polypropylene resin (hereinafter referred to as “PP”), peeling is likely to occur at the interface between PP and talc, which may reduce the impact resistance.

  A talc master batch (hereinafter referred to as “talc MB”) is prepared for the purpose of improving the dispersibility of talc in PP. That is, since talc MB contains talc in a high concentration and also contains PP and an elastomer component, the talc MB and a polypropylene resin for dilution (hereinafter referred to as “PP for dilution”). When the molding material mixed with is kneaded in an injection molding machine, the dispersibility of talc in PP is improved by the action of rubber that improves kneadability. Further, since rubber is dispersed around talc, interfacial peeling between talc and PP is suppressed. Furthermore, since PP is contained in talc MB, the affinity with the PP for dilution increases, and the molding material can be easily kneaded.

  Specifically, the talc MB according to the present embodiment is obtained by kneading and granulating the following components A to D. Hereinafter, each component will be described in detail.

Component A; Elastomer Component B; Crystalline Polypropylene Resin Component C; Talc Component D; Additive-About Elastomer (Component A)-
The elastomer component is added to increase the dispersibility of the talc component in the molded product (vehicle resin molded product) and to suppress the interfacial peeling between the talc and PP, thereby ensuring excellent impact resistance of the molded product. Is a rubber component. In the present specification, “elastomer component” and “rubber component” are synonymous. For convenience, the rubber component contained in talc MB is referred to as “elastomer component”, PP for dilution (component F) described later, and molding material. The rubber component contained in the molded product is referred to as “rubber component”.

  As described above, the blocking of talc MB occurs because the elastomer component contained in talc MB melts and adheres, aggregates and agglomerates between pellets in the talc MB drying step.

  Therefore, in order to suppress blocking of talc MB, it is effective to raise the melting temperature of the elastomer component in the drying process.

  FIG. 1 shows the results of differential scanning calorimetry (DSC measurement) of two types of elastomer components, ethylene-butadiene copolymer (EBR) and ethylene-octene copolymer (EOR).

  As indicated by the symbol M1 in FIG. 1, it can be seen that the EBR of this test is completely melted at about 60 ° C. with a melting rate of 100%. Assuming that the temperature at which the melting rate becomes 100% is “complete melting temperature” (° C.), as shown by the symbol M2 in FIG. 1, it can be seen that the complete melting temperature is about 80 ° C.

  The higher the complete melting temperature of the elastomer component, the more the melting of the elastomer component in the drying process can be suppressed. From such a viewpoint, in the talc MB according to the present embodiment, it is preferable to use an elastomer having a complete melting temperature of 80 ° C. or more as the elastomer component. Thereby, the melting of the elastomer component can be effectively suppressed in the drying step of talc MB described later. Thus, blocking between talc MB pellets can be suppressed.

  Specifically, the elastomer component having a complete melting temperature of 80 ° C. or higher used in the present embodiment is, for example, ethylene / octene copolymer rubber (EOR), ethylene / butadiene copolymer rubber having a complete melting temperature of 80 ° C. or higher, etc. Ethylene / α-olefin copolymer rubber, ethylene / propylene / ethylidene norbornene copolymer rubber (EPDM) and other ethylene / α-olefin / non-conjugated diene copolymer rubber, styrene / butadiene / styrene triblock copolymer Hydrogenated block copolymer rubbers such as hydrogenated product (SEBS), hydrogenated product of styrene-isoprene-styrene triblock copolymer (SEPS), (SBS), and the like.

  When the total amount of component A, component B and component C is 100 mass%, the blending ratio of the elastomer component (component A) suppresses blocking of talc MB and secures a sufficient blending ratio of the elastomer component. From the viewpoint of ensuring sufficient rigidity and impact resistance in the molded article, it is preferably 5% by mass or more and less than 26.5% by mass, more preferably 16% by mass or more and 26.4% by mass or less, and particularly preferably 21% by mass. It is 26 mass% or less.

  The melt flow rate of the elastomer (230 ° C., 2.16 kg load; hereinafter referred to as “MFR”) is not particularly limited, but the fluidity of the elastomer during talc MB production and the talc during injection molding are not limited. From the viewpoint of suppressing the blocking of talc MB during preliminary drying while ensuring the fluidity of MB, it is preferably 0.3 to 200 g / 10 minutes, more preferably 0.5 to 170 g / 10 minutes, and particularly preferably 0. .7 to 150 g / 10 min.

-Crystalline polypropylene resin (component B)-
The crystalline polypropylene resin (hereinafter referred to as “crystalline PP”) serves to suppress blocking of the talc MB in the drying step and facilitate uniform mixing with the PP for dilution in the melting step S3 described later. Have. That is, the inclusion of the crystalline PP in the talc MB improves the familiarity with the PP for dilution, and improves the kneadability between the talc MB and the PP for dilution.

  Specifically, the crystalline PP is, for example, a homopolymer of propylene (homopolypropylene), a majority weight of propylene and another α-olefin (for example, ethylene, 1-butene, 1-pentene, 1-hexene, 4 -Methyl-1-pentene, 1-octene, etc.), vinyl esters (eg, vinyl acetate), aromatic vinyl monomers (eg, styrene), vinyl silanes (eg, vinyl trimethoxy silane, vinyl trimethyl silane, etc.) And a binary block or a random copolymer or a graft copolymer. These may be used as a mixture of two or more. Among these, it is preferable to use a homopolypropylene, a propylene / ethylene random copolymer, or a propylene / ethylene block copolymer containing a crystalline polypropylene portion and an ethylene / propylene random copolymer portion.

  The blending ratio of the crystalline PP (component B) is preferably more than 20% by mass, more preferably 26.7% from the viewpoint of securing sufficient impact resistance in the molded product while suppressing blocking during the drying step. % Or more, particularly preferably 27.5% by mass or more, and preferably 45% by mass or less, more preferably 33% by mass or less, and particularly preferably 32% by mass or less.

  The MFR (230 ° C., 2.16 kg load) of the crystalline PP is not particularly limited, but is preferably 0.1 to 300 g / 10 min from the viewpoint of ensuring the fluidity of the molding material at the time of injection molding. More preferably, it is 0.2 to 250 g / 10 minutes, and particularly preferably 0.3 to 200 g / 10 minutes.

-About talc (component C)-
Talc is mixed to increase the rigidity and heat resistance of the molded product. Talc is a layered mineral based on magnesium silicate.

  Talc is a particulate form having an average particle diameter (D50) of preferably 1 to 30 μm, more preferably 2 to 20 μm, from the viewpoint of ensuring good dispersibility in the molded product and ensuring excellent rigidity of the molded product. It is. The average particle diameter (D50) is a median diameter (median diameter), and is a diameter in which the larger side and the smaller side are equivalent when the particle size distribution of the measured powder is divided into two. Generally, it is measured by a wet laser diffraction / scattering method.

  Talc is mechanically pulverized naturally produced using jaw crusher, hammer crusher, roll crusher, screen mill, jet crusher, colloid mill, roller mill, vibration mill, etc. It can be obtained by wet or dry classification once or repeatedly with an apparatus such as a cyclone, a cyclone air separator, a micro separator, or a sharp cut separator.

  Talc grafts various organic titanate coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or anhydrides for the purpose of improving adhesion and dispersibility with elastomers and / or crystalline PP. A modified polyolefin, fatty acid, fatty acid metal salt, fatty acid ester, or the like may be used.

  The blending ratio of talc (component C) is preferably 46% by mass or more and 70% by mass or less, more preferably 46% by mass from the viewpoint of improving the rigidity of the molded product while ensuring good dispersibility in the molded product. It is more than 50% by mass, particularly preferably 46% by mass to 48% by mass.

  Talc preferably has a high degree of whiteness from the viewpoint of improving the paintability of the molded product, and is preferably 80 or more, for example. The whiteness W can be calculated by the following formula (2) from the lightness (L), hue, and saturation (a, b) of the powder color measured using a colorimetric color difference meter.

W = 100 − {(100−L) ² + a ² + b ² } ^1/2 (2)
Ig-Loss (loss on ignition) can be quantified from the weight loss by firing the talc sample at 1050 ° C. for 1 hour, allowing it to cool. Ig-Loss is preferably 6 or less from the viewpoint of improving the flexural modulus of the molded product.

-About additive (component D)-
The additive is added in order to impart functions such as antioxidation and light resistance to the molded product, and to improve the kneadability of the components A to C. Specifically, the additive includes, for example, phenolic and phosphorus antioxidants, hindered amines, benzophenones, benzotriazoles, light-proofing agents and weathering resistance inhibitors, nucleating agents such as organoaluminum compounds and organophosphorus compounds, Colorants such as quinacridone, perylene, phthalocyanine, titanium oxide, carbon black, azo pigments, petals, ultramarine blue, fibrous potassium titanate, fibrous magnesium oxysulfate, fibrous aluminum borate, calcium carbonate whiskers, carbon fibers And filler components such as glass fiber, and polymer components such as high-density polyethylene and low-density polyethylene. In addition, when an inorganic filler such as talc is kneaded into a polymer, metal soaps such as calcium stearate and zinc stearate generally used for the purpose of improving the dispersibility and kneadability of talc, and glyceride stearate. A surfactant, a fluorine polymer compound, or the like may be used as an additive.

  From the viewpoint of ensuring good rigidity and impact resistance of the molded product while imparting a desired function to the molded product, the amount of the additive added to the component B is 100 parts by mass. On the other hand, it is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and particularly preferably 0.1 to 3 parts by mass.

-Shape and size of talc MB-
The shape of the talc MB is not particularly limited, and can be a general shape such as a spherical shape, a pellet shape, or a block shape, but is preferably a pellet shape from the viewpoint of ease of manufacture. The size of talc MB is preferably about 2 mm square to about 4 mm square from the viewpoint of improving kneadability with PP for dilution during injection molding.

-Blocking rate-
As a result of intensive studies, the present inventors have found a blocking evaluation method for quantifying the degree of occurrence of blocking during preliminary drying of talc MB. Hereinafter, the method of the blocking evaluation test will be described with reference to FIGS.

  As shown in FIG. 2, the pellet-shaped test talc MB13 is put into the container 12 by a predetermined mass Y (g), and the pressing container 14 is inserted into the container 12 from above the test talc MB13. Then, a 20 kg load 15 is placed on the upper side of the pressing container 14 as a mass converted on the assumption of a dryer, and is heated in the thermostat 11. The heating temperature is, for example, 60 ° C. or more and less than 80 ° C. The heating time is, for example, 1.5 hours or more and 5 hours or less.

  The test talc MB13 after the completion of heating is taken out from the thermostat 11, and left at 25 ° C. for about 15 minutes to 2 hours, for example, and then passed through a sieve 21 as shown in FIG. The size of the sieve 21 is such that a plurality of pellets agglomerated and agglomerated while passing through one test talc MB13 pellet does not pass. Depending on the size of the pellet, the pellet is about 3 mm square. For example, the size is about 3.5 mm to 5.5 mm. When passing through the sieve 21 in this way, the block portion 13A (blocked portion) of the test talc MB13 remains on the screen 21 and the pellet portion 13B not blocking is indicated by an arrow in the figure. As indicated by 23, it passes through the eyes of the sieve 21 and falls on the lower petri dish 22.

  Thus, the degree of occurrence of talc MB blocking was quantified as the “blocking rate”. That is, the blocking rate P (%) is given by the following formula (1), where the mass of the lump portion 13A is X (g).

P (%) = X (g) / Y (g) × 100 (1)
4 and 5 show the evaluation test results when the blocking ratios are 90% and 5%, respectively, that is, the state after the process of FIG. In FIG. 4, the lump portion 13A of the test talc MB13 remains as a large lump on the sieve 21 and a small amount of the pellet portion 13B falls on the lower petri dish 22. On the other hand, in FIG. 5, the lump portion 13A remaining on the sieve 21 is very small and several lump pellets are dispersed, and most of the test talc MB13 falls into the lower petri dish 22 as the pellet portion 13B. You can see that

  As described above, according to the blocking evaluation test, the degree of talc MB blocking can be easily quantified. Thus, the blocking rate calculated in the blocking evaluation test is preferably 8% or less from the viewpoint of suppressing the blocking of talc MB at the drying step S1 described later and enabling continuous supply of talc MB. More preferably, it is 7% or less, and particularly preferably 6% or less.

-Method for producing talc MB-
The talc MB is charged with a predetermined amount of each of the components A to D into a kneader such as a roll kneader, a Banbury kneader, a kneader kneader, a uniaxial or biaxial extruder, and softened by heating. After kneading by applying shear, it can be produced by molding into a pellet.

<Molded product>
The molded product according to this embodiment is obtained by injection molding a molding material in which the following component E and component F are mixed.

Component E: Talc MB according to this embodiment
Component F: Polypropylene resin for dilution -About talc MB (component E)-
As talc MB, what was manufactured with the above-mentioned composition and method is used.

  The amount of talc MB is preferably 38 from the viewpoint of improving the dispersibility of talc in the molded product by obtaining the total of component E and component F as 100 parts by mass and obtaining a molded product having excellent rigidity and impact resistance. The amount is not less than 65 parts by mass and more preferably not less than 45 parts by mass and not more than 63 parts by mass, particularly preferably not less than 50 parts by mass and not more than 62 parts by mass.

-PP for dilution (component F)-
The PP for dilution is for constituting the skeleton of the molded product, and the same PP as the component B described above can be used. Specifically, for example, homo PP, which is a polymer containing a propylene component, a block copolymer containing a PP component (for example, a block copolymer of propylene and ethylene), a random copolymer containing a propylene component, etc. Can be mentioned.

  As the PP for dilution, those having the same shape and size as those of talc MB can be used from the viewpoint of improving kneadability with talc MB at the time of injection molding.

  The PP for dilution contains a rubber component from the viewpoint of enhancing the dispersibility of talc and the adhesion between talc and PP in the molded product. Specific examples of the rubber component contained in the PP for dilution include ethylene / propylene copolymer, ethylene / butene copolymer, ethylene / hexene copolymer rubber, ethylene / octene copolymer, ethylene / propylene / ethylidene. Examples thereof include norbornene copolymer (EPDM), hydrogenated product of styrene-butadiene-styrene triblock copolymer (SEBS), and hydrogenated product of styrene-isoprene-styrene triblock copolymer (SEPS).

  The blending amount of PP for dilution is preferably 35 parts by mass or more and 62 parts by mass or less, more preferably 36 parts by mass or more and 60 parts by mass or less, from the viewpoint of improving moldability, with the total of component E and component F being 100 parts by mass. Particularly preferred is 37 parts by weight or more and 58 parts by weight or less.

-Characteristics of molded products-
The content of the talc component with respect to the total amount of the component E and the component F is preferably 17% by mass to 37% by mass, more preferably 18% by mass to 37% by mass, and particularly preferably 19% by mass to 37% by mass. It is as follows.

  The use of the molded article is a part used for a vehicle outer plate such as a hood, a roof, a spoiler, a door, a rear garnish, a side step molding, a fender, and a bumper. Further, the present invention is not limited to the outer plate, and may be applied to interior parts for automobiles such as instrument panels, door trims, pillar trims, side protectors, and console boxes, and interior and exterior parts for vehicles such as airplanes and trains.

-Manufacturing method of molded products-
The molded product according to this embodiment can be manufactured, for example, by the following procedure. That is, as shown in FIG. 6, the method for manufacturing a molded product according to this embodiment includes a drying step S1, a mixing step S2, a melting step S3, a molding step S4, and a post-processing step S5. .

[Drying process]
The drying step S1 is a step for pre-drying talc MB having a high hygroscopic property. Specifically, talc MB pellets are put into a drying hopper and dried while heating.

  FIG. 7 shows the change over time in the moisture content at various temperatures for talc MB of Example 3 to be described later. As shown by the alternate long and short dash line in FIG. 7, a moisture content of 0.06% or less is a desirable range. It can be seen that at a drying temperature of 60 ° C., the moisture content is about 0.07% even after 240 minutes (4 hours), and does not become 0.06% or less. It can be seen that at a drying temperature of 65 ° C., 70 ° C., 75 ° C., and 80 ° C., the moisture content is 0.06% or less after about 2.5 hours, 2.2 hours, and 1.3 hours, respectively. At 80 ° C. or higher, although the drying time is short, the temperature becomes equal to or higher than the complete melting temperature of EOR, which is an elastomer component, and there is a possibility that the possibility of blocking talc MB in the drying step S1 may be increased.

  Therefore, the drying temperature in the drying step S1 is preferably more than 60 ° C. and less than 80 ° C., more preferably from the viewpoint of drying until reaching the desired moisture content while suppressing the melting of the elastomer component and suppressing blocking of talc MB. Is from 65 ° C to 75 ° C.

  The drying time is preferably 1.5 hours or more, more preferably 1.8 hours or more, particularly preferably 2 hours or more from the viewpoint of suppressing talc MB blocking and drying to a desired moisture content. The upper limit of the drying time is not particularly limited, and can be appropriately determined in consideration of the scale of the production facility, etc., but can be within 5 hours, for example, from the viewpoint of work efficiency.

[Mixing process]
In the mixing step S2, the talc MB as the component E dried in the drying step S1 and the PP for dilution as the component F are dry blended to obtain a molding material in which both pellets are uniformly mixed. This is a step for obtaining a uniform molten plastic in the melting step S3. Specifically, talc MB and PP for dilution are mixed with a tumbler or the like to obtain a molding material. The talc MB and the PP for dilution that have been pre-dried in the drying step S1 are automatically fed to the tumbler after weighing and mixed.

  The mixing step S2 is an optional step, and the talc MB and the PP for dilution may be respectively weighed and then directly put into a hopper of an injection molding machine, which will be described later, and heated, melted and kneaded. From the viewpoint of shortening the heating time in the melting step S3 and obtaining a molded product in which the constituent components are uniformly mixed and dispersed, a molding material in which talc MB and PP for dilution are mixed in advance in the mixing step S2 is prepared. It is desirable.

[Melting process]
In the melting step S3, the molding material uniformly mixed in the mixing step S2 is heated and melted and kneaded to obtain a molten plastic.

  Specifically, it is possible to obtain a molten plastic by putting a molding material into a hopper of an injection molding machine, heating in a cylinder of the injection molding machine to melt the resin component, and applying a shear with a screw and kneading. it can.

  The heating temperature in the melting step S3, that is, the molding temperature, is preferably 180 ° C. from the viewpoint of melting all the molding material so that the components are uniformly mixed and dispersed, and shortening the cooling time in the molding step S4. The temperature is 400 ° C. or lower, preferably 210 ° C. or higher and 350 ° C. or lower, preferably 220 ° C. or higher and 300 ° C. or lower.

  The melting time is not particularly limited and can be appropriately set according to the production amount or the like. From the viewpoint of melting all the molding materials and uniformly mixing and dispersing the components, for example, 30 More than a minute.

[Molding process]
In the molding step S4, an injection molded product can be obtained by injecting a predetermined amount of the molten plastic prepared in the melting step S3 into a mold and cooling. Note that the injection molding machine used in the melting step S3 and the molding step S4 preferably has a kneading ability increased by a screw shape, a mixing nozzle or the like.

  The molding time is not particularly limited and can be appropriately determined depending on the type, size, shape, and the like of the molded product.

  The cooling time is not particularly limited and can be appropriately determined depending on the type, size, and shape of the molded product, the above-described molding temperature, and the like, and can be, for example, 2 hours or more.

[Post-processing process]
The injection molded product obtained in the molding step S4 is subjected to a post-processing step S5 such as deburring as necessary, and a final product is obtained. The post-processing step S5 is an optional step, and is set as necessary depending on the type, shape, size, etc. of the molded product.

(Other embodiments)
Hereinafter, other embodiments according to the present invention will be described. The same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In Embodiment 1, the talc masterbatch was configured to be molded by an injection molding method after dry blending with the PP resin for dilution. The molding method is not particularly limited, and other than the injection molding method, for example, an injection compression molding method, a hollow molding method and the like that are generally performed in the synthetic resin field may be used.

  Next, specific examples will be described.

-About Talc MB-
In Table 1, about the talc MB of Examples 1-10 and Comparative Examples 1-14, the compounding ratio and blocking evaluation result of an elastomer component, crystalline PP component, and a talc component are shown.

[Example 1]
<Preparation of talc MB>
As shown in Table 1, EOR (Dow Chemical Japan Co., Ltd., Engagement 8100, MFR: 1.0 g / 10 min) 21.6% by mass as elastomer component A, Polypropylene as PP component B (Bruge Japan, BJ368MO) , MFR: 100 g / 10 min) 32.4% by mass, component B talc (Nippon Talc Co., Ltd., RT25RC) 46% by mass, and component D additive (Son-on antioxidants 1010 and 1680, manufactured by Son-on Co., Ltd.) Predetermined amounts of the respective components were prepared so that talc MB having a composition of 2 parts by mass of the light resistance agents UV70 and UV7120) was formed with respect to 100 parts by mass of components A to C.

  Next, the prepared EOR, PP, talc, and additives are put into a twin-screw extruder (manufactured by Nippon Steel Works) with a cylinder diameter of 60 mm, kneaded while melting the resin component, and the extruded strand is cooled with water and then predetermined. By cutting into lengths, pellet-shaped talc MB having a height of about 3 mm and a diameter of about 3 mm was obtained.

[Examples 2 to 4, Comparative Examples 1 and 2]
Talc MB was prepared in the same manner as in Example 1 except that the blending ratio of EOR and crystalline PP was changed to the values shown in Table 1.

[Comparative Examples 4 to 18]
Example 1 except that EBR (Mitsui Chemicals, DF610, MFR: 1.0 g / 10 min) was used as the elastomer component, and the blending ratio of the elastomer component and crystalline PP was changed to the values shown in Table 1. Talc MB was prepared in the same manner as above.

[Examples 5 to 10, Comparative Example 3]
Talc MB was prepared in the same manner as in Example 1 except that the blending ratio of EOR, crystalline PP, and talc was changed to the values shown in Table 1.

-Various measurements of ingredients and talc MB-
<DSC measurement>
The EBR and EOR of the elastomer component A were measured using a differential scanning calorimeter (DSC8500, manufactured by Perkin Elmer).

<MFR>
MFR (g / 10 minutes) of component A (elastomer) and component B (crystalline PP resin) was measured at 230 ° C. and a load of 2.16 kg in accordance with JIS K7210.

<Moisture content measurement>
About 10 g of talc MB prepared in Example 2 as described above, changes with time in moisture content at various drying temperatures were measured using a heat drying moisture meter (MS-70, manufactured by A & D Corporation).

<Blocking evaluation test>
A load of 20 kg was placed on 100 g of talc MB prepared as described above, and heated at 70 ° C. for 2.5 hours in a thermostatic bath.

  Talc MB after completion of heating was taken out of the thermostatic bath, left at 25 ° C. for 30 minutes, and then sieved. The sieve mesh was about 8 mm. It isolate | separated into the lump part which has raise | generated blocking among the test talc MB, and the pellet part which has not raise | generated blocking. And the mass of the lump part was measured and the blocking rate (%) was computed using the said Formula (1). Table 1, FIG. 8 and FIG. 9 show the conditions and results of the blocking evaluation test.

  FIG. 8 shows changes in the blocking rate with respect to the blending ratios of two types of elastomers, EBR and EOR, for Examples 1 to 4 and Comparative Examples 1, 2, and 4 to 14. According to the result of EBR, as can be seen from the regression curve indicated by the solid line in FIG. 8, the blocking rate decreases as the elastomer component decreases. It can also be seen that when the elastomer component is changed from EBR to EOR, the blocking rate is significantly reduced. From this, melting in the drying step S1 of the elastomer component is one of the causes of blocking, and as described above, blocking can be effectively suppressed by adopting EOR having a higher complete melting temperature than EBR. I know that there is. 4 and 5 described above are photographs showing the results of the blocking evaluation tests of Comparative Example 14 and Example 3, that is, the stage where the process of FIG. 3 is completed.

  It is desirable from the viewpoint of suppressing the blocking of talc MB at the time of preliminary drying that the blocking rate indicated by a thick dashed line in FIG. 8, that is, the blocking rate is 8% or less. When EOR is used, it is considered that a desired blocking rate can be obtained when the blending ratio of EOR is less than about 26.5% by mass.

  Moreover, FIG. 9 has shown the change of the blocking rate with respect to the compounding ratio of crystalline PP about Examples 5-10 and the comparative example 3. FIG. As can be seen from the regression curve shown by the solid line in FIG. 9, it can be seen that the blocking rate decreases as the blending ratio of crystalline PP increases. Thus, the blocking of talc MB can be suppressed by adding crystalline PP to talc MB.

-About molded products-
50 parts by mass of talc MB of Example 2 and 50 parts by mass of PP for dilution, which were pre-dried at 70 ° C. for 2.5 hours in the drying process, were mixed with a tumbler, and then mixed into a hopper of an injection molding machine. It was heated and melted to obtain a molten plastic. Then, the molten plastic was poured into a sample mold for molding, and after cooling, deburring was performed as necessary to obtain a sample molded product.

  On the other hand, when the talc MB of Comparative Example 14 was pre-dried at 90 ° C. for 2 hours in the drying step, blocking of the talc MB occurred, making it difficult to supply the material, and a molded product could not be obtained.

  The present invention is extremely useful because it can suppress melting of the elastomer component during preliminary drying and suppress blocking of the pellets.

11 Constant temperature bath 12 Container 13 Test talc MB (talc masterbatch)
13A lump portion 13B pellet portion 14 container 15 for pressing load 21 sieve 22 petri dish

Claims (5)

A talc master batch obtained by kneading and granulating the following components A to D.
Component A: Elastomer having a complete melting temperature of 80 ° C. or more: 5% by mass or more and less than 26.5% by mass Component B: Crystalline polypropylene resin: more than 20% by mass and 45% by mass or less Component C: Talc: 46% by mass or more and 70% by mass % Or less Component D; Additive: 0.01 mass part or more and 5 mass parts or less (mass of component B is 100 mass parts (provided that the total of component A, component B, and component C is 100 mass%)) In the talc masterbatch according to claim 1,
A blending ratio of the component A is 21% by mass or more and 26% by mass or less. In the talc masterbatch according to claim 1 or 2,
The blending ratio of the component B is 26.7% by mass or more and 33% by mass or less,
A blending ratio of the component C is 46% by mass or more and less than 50% by mass, and the talc master batch. In the talc masterbatch according to any one of claims 1 to 3,
The blocking rate P (%) represented by the following formula (1) when dried at 70 ° C. for 2.5 hours under a pressure of 20 kg with respect to a predetermined mass Y is 8% or less. Talc master batch.
P = X / Y × 100 (1)
(However, in formula (1), X represents the mass of the agglomerated portion.) A method for producing a resin molded product for a vehicle using the talc masterbatch according to any one of claims 1 to 4,
A drying step of drying 38 parts by mass or more and 65 parts by mass or less of the talc master batch as component E at a temperature of more than 60 ° C. and less than 80 ° C. for 1.5 hours or more;
A melting step of obtaining molten plastic by heating and melting 35 parts by mass or more and 62 parts by mass or less of the polypropylene resin for dilution as the component E and the component F dried in the drying step;
And a molding step of injecting the molten plastic into a mold to obtain an injection molded product.
(However, the total of component E and component F is 100 parts by mass.)