JPH08134290A - Propylene resin composition and preparation thereof - Google Patents

Abstract

PURPOSE: To provide a propylene resin compsn. which is highly crystalline and has excellent rigidity and heat resistance and, in particular, very high heat distortion temp. CONSTITUTION: A propylene resin compsn. comprising: 100 pts.wt. propylene resin; and 0.0001 to 10 pts.wt. acicular org. crystal nucleating agent. 100 pts.wt. propylene resin is mixed with 0.0001 to 10 pts.wt. org. crystal nucleating agent capable of forming an acicular shape in the propylene resin, and the mixture is melt-kneaded at least such a temp. that the crystal nucleating agent is dissolved in a melt of the propylene resin, followed by cooling, thereby incorporating an acicular nucleating agent into the propylene resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a propylene-based resin composition containing a crystal nucleating agent having a special shape and having high crystallinity, excellent rigidity and heat resistance, and a particularly high heat distortion temperature, and a method for producing the same. It is about.

[0002]

2. Description of the Related Art Crystalline polypropylene resins have excellent mechanical properties and thermal properties and are used in a wide range of applications as raw material resins for various molded products. In particular, in recent years, the utilization in the field of industrial parts has spread due to its rigidity and heat resistance. Conventionally, generally, in order to improve the rigidity and heat resistance of polypropylene resins, addition of a crystal nucleating agent (sometimes called a nucleating agent or simply a nucleating agent) and an inorganic filler such as glass, mica, talc, etc. Are being added. As a method of adding such a crystal nucleating agent to a propylene-based resin, generally, a method of mixing powder of the crystal nucleating agent with resin powder or pellets and melt-kneading with a kneader is adopted. Kneaded product (pellet) obtained by
Was further processed by injection molding, extrusion molding, sheet molding or the like to obtain a molded body.

[0003]

DISCLOSURE OF THE INVENTION In general, a problem when blending a crystal nucleating agent with a propylene resin is dispersibility of the crystal nucleating agent. For example, when the dispersion of the crystal nucleating agent was poor, the function as the crystal nucleating agent was not sufficiently exhibited, and the transparency of the mixture was adversely affected.
Therefore, in order to solve such a problem, at present, the solution is mainly aimed at by improving the kneading technique. However, such improvement of the kneading technique is not always sufficient to improve the dispersibility, rigidity and heat resistance of the crystal nucleating agent.

[0004]

[Means for Solving the Problems]

[Summary of the Invention] As a result of intensive investigations by the present inventors for the purpose of improving the dispersibility of a crystal nucleating agent, the crystal nucleating agent is treated in a resin by treating it with a specific crystal nucleating agent under specific conditions. In the present invention, they have found that they can take a characteristic shape and can improve the heat distortion temperature to a surprising degree, and arrived at the present invention. That is, the propylene-based resin composition of the present invention is characterized by containing 0.0001 to 10 parts by weight of the organic crystal nucleating agent having a needle-like shape with respect to 100 parts by weight of the propylene-based resin. It is what In the method for producing a propylene-based resin composition, which is another aspect of the present invention, an organic crystal nucleating agent capable of forming a needle-like shape in the propylene-based resin is added to 100 parts by weight of the propylene-based resin. 0001 to 10 parts by weight, and the mixture is melt-kneaded at a temperature equal to or higher than the melting temperature of the propylene-based resin melt of the crystal nucleating agent and then cooled to contain the nucleating agent having an acicular shape. It is characterized by that.

[Detailed Description of the Invention] [I] Propylene-based resin composition (1) Constituent component (a) Propylene-based resin The propylene-based resin constituting the propylene-based resin composition of the present invention includes propylene alone Examples thereof include a coalesce or a copolymer containing propylene as a main component. Examples of the copolymer containing propylene as a main component include other 1-alkenes containing propylene as a main component (ethylene, 1-butene, 1-pentene, 1-hexene, 4
-Methylpentene-1 etc.) (including random and block), propylene / ethylene multi-component copolymer (5-ethylidene-2-norbornene, 5-methylene-2-norbornene or 1,4 -Including hexadiene), a copolymer of propylene and a comonomer such as styrene, maleic anhydride, (meth) acrylic acid, and the like. Furthermore, in the propylene-based polymer,
A resin obtained by blending a thermoplastic resin such as high-density polyethylene, polybutene-1, poly-4-methylpentene-1 and the like within a range that does not significantly impair the effects of the present invention can also be mentioned.

The propylene-based polymer can be produced by applying a conventionally known production method. The catalyst used in the production is not particularly limited, and examples thereof include a catalyst system containing a titanium-containing solid catalyst component and an organoaluminum compound as a cocatalyst component. The titanium-containing solid catalyst component is a known carrier-supported catalyst component obtained by contacting a solid magnesium compound, titanium tetrahalide and an electron-donating compound, titanium trichloride or a known titanium trichloride as a main component. It is selected from catalyst components. Further, in addition to the above solid catalyst component and cocatalyst component, a catalyst system using a known electron donating compound as the third component may be used. In addition to these catalyst systems, metallocene catalysts, so-called Kaminsky catalysts, can also be used. As the polymerization method used for the production, hexane, a slurry polymerization method using a hydrocarbon such as heptane as a solvent, a bulk polymerization method using liquid propylene as a solvent, a vapor phase method, and the like, and various known methods can be given. You can The melt flow rate of the propylene-based resin (hereinafter, simply abbreviated as “MFR”; defined by the provisions of ASTM D1238) is appropriately selected according to the molding method to which it is applied.
0.01 to 500 g / 10 minutes, preferably 0.1 to
About 200 g / 10 minutes is used.

(B) Organic Crystal Nucleating Agent The needle-shaped organic crystal nucleating agent that constitutes the propylene-based resin composition of the present invention means that the organic crystal nucleating agent in the propylene-based resin has a needle-like crystalline state. It is present in a dispersed state. Form The needle crystal of the organic crystal nucleating agent of the present invention is, in the simplest case, the organic crystal nucleating agent is a single needle-shaped crystal itself, but only in the case of these single needle-shaped crystal shapes. The present invention is not limited, and may be an aggregate or a combination thereof, for example, a feather-like shape in which needle-like crystals are radially grown, or an aggregate of other needle-like crystals. . The organic crystal nucleating agent consisting of these needle-like crystals is present in the propylene-based resin and exerts some influence. Therefore, the high crystallinity, rigidity, and heat resistance of the present invention are excellent, and particularly the heat distortion temperature It seems that the remarkably high effect of the propylene resin composition can be exhibited. The nucleating agent does not necessarily need to be needle-shaped before being mixed with the propylene resin.

[0008] As types such organic nucleating agent may be any one so long as it is an organic crystal nucleating agent that can form a shape composed of the acicular crystals in the propylene-based resin, specifically, Examples thereof include amide compounds represented by the following general formulas (1) to (3). Formula ^{R 2 -NHCO-R 1 -CONH-} R 3 (1) R 2 -CONH-R 1 -CONH-R 3 (2) R 2 -CONH-R 1 -NHCO-R 3 (3) ( in the formula , R ¹ represents a saturated or unsaturated aliphatic, alicyclic or aromatic hydrocarbon group having ¹ to 28 carbon atoms, preferably 2 to 20 carbon atoms, and R ² and R ³ may be the same or different. Well, a cycloalkyl group or a cycloalkenyl group having 3 to 18 carbon atoms, preferably 6 to 18 carbon atoms,

[0009]

Embedded image

[0010] or

[0011]

[Chemical 6]

Represents a group represented by Note that R in the formula^Four,
R^FiveIs a hydrogen atom or 1 to 12 carbon atoms, preferably 1 to
8 straight chain or branched chain alkyl group, alkenyl
Represents a group, a cycloalkenyl group or a phenyl group, R⁶,
R⁷Is a straight chain having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms or
It represents a branched alkylene group. ) In the above general formula (1), general formula (2) and general formula (3)
Hydrocarbon group R included ¹As, more preferably linear
The alkyl group and the following hydrocarbon groups are exemplified.

[0013]

[Chemical 7]

[0014]

Embedded image

[0015]

[Chemical 9]

[0016]

[Chemical 10]

Or

[0018]

[Chemical 11]

(In the formula, X is --CH _2- , --O--, --SO
_{2 -, - S -, -} CO-, or -C (CH _{3) 2} - represents a. Further, as R ² and R ³ , more preferable examples include a cycloalkyl group and a substituted product thereof, an aromatic hydrocarbon group and a substituted product thereof. More preferably, cyclohexyl group, 2-methylcyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, 2-ethylcyclohexyl group, 3-ethylcyclohexyl group, 4
-Methylcyclohexyl group, 2-propylcyclohexyl group, 2-isopropylcyclohexyl group, 4-propylcyclohexyl group, 4-isopropylcyclohexyl group, 2-tert-butylcyclohexyl group, 4-n-
Butylcyclohexyl group, 4-isobutylcyclohexyl group, 4-sec-butylcyclohexyl group, 4-te
rt-butylcyclohexyl group, 4-n-amylcyclohexyl group, 4-isoamylcyclohexyl group, 4-s
ec-amylcyclohexyl group, 4-tert-amylcyclohexyl group, 4-hexylcyclohexyl group, 4
-Heptylcyclohexyl group, 4-octylcyclohexyl group, 4-nonylcyclohexyl group, 4-decylcyclohexyl group, 4-undecylcyclohexyl group, 4-
Substituted products of cyclohexyl groups such as dodecylcyclohexyl group, 4-cyclohexylcyclohexyl group and 4-phenylcyclohexyl group are exemplified.

That is, among the amide compounds represented by the general formula (1), the general formula (2) or the general formula (3), preferred compounds are exemplified by N, N'-dicyclohexyl-1,4-. Cyclohexanedicarboxamide, N, N'-dicyclohexyl-terephthalamide,
N, N'-dicyclohexyl-2,6-naphthalene dicarboxamide, N, N'-dicyclohexyl-4,4
′ -Biphenyldicarboxamide, p- (N-cyclohexanecarbonylamino) benzoic acid cyclohexylamide, N, N′-dicyclohexanecarbonyl-p-phenylenediamine, N, N′-dicyclohexanecarbonyl-1,4-diaminocyclohexane Etc. can be mentioned. These amide compounds can also be used in a mixture. The amide compound is known as a crystal nucleating agent for selectively growing β crystal which is one of the crystal modifications of polypropylene (Japanese Patent Application Laid-Open No. 262936/1993).
JP-A-6-107875), it is not yet known that this can form a needle-like shape in a propylene resin.

(2) Blending ratio In the propylene resin composition of the present invention, the organic crystal nucleating agent having a needle-like shape is uniformly dispersed in the propylene resin and has the needle-like shape. The organic crystal nucleating agent is 0.0001 to 1 with respect to 100 parts by weight of the propylene resin.
The content is 0 parts by weight, preferably about 0.001 to 1 part by weight, more preferably about 0.005 to 0.5 part by weight. When the amount is less than the above range, the effect of the crystal nucleating agent is scarcely seen, while when the amount is more than the above range, no significant difference in effect is observed, which is economically disadvantageous. When the propylene-based resin composition containing the organic crystal nucleating agent is used as a masterbatch, a large amount of the nucleating agent is blended to form a composition, which is appropriately diluted in the above blending ratio range for molding. Can be offered.

(3) Other compounding agents (optional components) In using the propylene resin composition of the present invention, other compounding agents may be added, if necessary, within a range that does not significantly impair the effects of the present invention. can do. Specific examples of such compounding agents include ultraviolet absorbers, optical brighteners, antioxidants, neutralizing agents, antacids, flame retardant substances, antistatic agents,
Lubricants, antiblock agents, pigments, fillers, antibacterial agents, physical property adjusting agents (elastomers, other resins, etc.), molecular weight adjusting agents (radical generators), cross-linking agents, foaming agents and the like can be mentioned. These compounding agents can be used alone or in combination of two or more kinds.

[II] Production of Propylene-Based Resin Composition A propylene-based resin composition comprising a propylene-based resin and an organic crystal nucleating agent having a needle-like shape as described above is a propylene-based resin containing an organic crystal nucleating agent. Then, if necessary, the above-mentioned other compounding agent is compounded, and the compound is manufactured by melt-kneading the crystal nucleating agent at a temperature equal to or higher than the melting temperature of the propylene resin melt and then cooling. Melt-kneading Melt-kneading is performed at a temperature equal to or higher than the melting temperature of the organic crystal nucleating agent in the propylene resin melt. If the temperature of the melt-kneading is lower than the melting temperature of the organic crystal nucleating agent in the propylene resin melt, it cannot be used as a crystal nucleating agent having an acicular shape. The melt-kneading can be carried out using a normal kneader such as a single-screw or twin-screw extruder, roll, Banbury mixer, kneader blender. Cooling the cooling the propylene resin melt, the organic crystal nucleating agent dissolved in propylene resin melt having a needle-like shape precipitated in such a propylene resin. Cooling is performed at a temperature below its deposition temperature. That is, in the propylene-based resin composition melt-extruded at a temperature equal to or higher than the melting temperature of the propylene-based resin melt of the organic crystal nucleating agent, in the propylene-based resin composition cooled under the cooling temperature, the amide-based compound that is the organic crystal nucleating agent, etc. It is contained as a crystal having a needle-like shape. Crystals of such an organic crystal nucleating agent having a needle-like shape are observed with a polarization microscope or the like.

[III] Molding of Propylene Resin Composition As a method for molding the propylene resin composition of the present invention, various molding methods such as injection molding, extrusion molding, compression molding and the like can be adopted. When the obtained molded body is observed with an electron microscope or the like, it is found that the crystal nucleating agent having a needle-like shape is finely dispersed. Since such a propylene resin composition of the present invention contains a crystal nucleating agent having a special shape, it has high crystallinity, excellent rigidity and heat resistance, and in particular has a significantly high heat distortion temperature.

[0025]

EXAMPLES The present invention will be described in more detail below with reference to experimental examples. In the experimental examples shown below, evaluation was performed by the evaluation method shown below. [I] Evaluation method Flexural modulus: Measured in accordance with ASTM D790-86. Deflection temperature under load: In accordance with JIS K7207,
A sample annealed at 120 ° C. for 30 minutes was used. The bending stress applied to the sample was 4.6 kg / cm ² . Impact strength (IZOD): Measured according to JIS K7110. MFR: Measured according to ASTM D1238.

[II] Experimental Example Example 1 (1) Melt-kneading Polypropylene homopolymer pellets (MFR: 4.7)
g / 10 min) 100 parts by weight, N as an organic crystal nucleating agent,
0.2 parts by weight of granular powder of N'-dicyclohexyl-2,6-naphthalene dicarboxamide was added, and further B
HT (2,6-ditert-butyl-4-methylphenol) 0.1% by weight, IRGANOX 1010
0.1% by weight of [trade name, stabilizer manufactured by Ciba-Geigy, pentaerythrityl-tetrakis {3-3,5-di-t-butyl-4-hydroxyphenyl} propionate],
IRGAFOS 168 [trade name, flame retardant manufactured by Ciba-Geigy, tris (2,4-di-t-butylphenyl) phosphite] was added in an amount of 0.1% by weight, and an extruder (a twin-screw extruder manufactured by Toyo Seiki Co., Ltd.) was added. LABO PLASTMILL3
0C150) four heating zones are set to temperatures of 270 ° C. (feeding part), 300 ° C., 300 ° C. and 290 ° C. (die top part), and the number of revolutions of the extrusion screw is 100.
Melt kneading was performed by operating at rpm. In addition, N, N '
-Dicyclohexyl-2,6-naphthalene dicarboxamide dissolves in the polypropylene melt at temperatures above 270 ° C. The obtained melt was extruded as a strand, cooled in a water tank in which water at room temperature was passed, and then pelletized by a pelletizer.

(2) Injection molding Using the above pellets, three heating zones of a 0.8 oz injection molding machine (J-28SA) manufactured by Nippon Steel Co., Ltd. were heated to 200 ° C.
(Supply part), 230 ° C., 220 ° C. (die top part), and injection molding was performed at a mold temperature of 40 ° C. to prepare a test piece.

(3) Evaluation A thin piece was cut out from the pellets obtained above, and the thin piece was melted at a temperature of 200 ° C. and observed by a polarizing microscope. We confirmed the shape of crystals that grew radially like feathers (Fig. 1
reference). In addition, when observing the thin piece before melting with a polarization microscope, a structure different from a general spherulite structure, which reflects the shape of this unique organic crystal nucleating agent, was confirmed (see FIG. 2). A thin piece was cut out from the injection-molded piece, stained with ruthenium tetraoxide, and then observed with a transmission electron microscope. As a result, it was confirmed that the acicular organic crystal nucleating agent was dispersed (see FIG. 3, arrow). ). This is because the injection molding temperature is lower than the melting temperature of the organic crystal nucleating agent with respect to polypropylene, so that the organic crystal nucleating agent radially grown like the feather shown in FIG. It is sometimes pulverized and finely dispersed as an acicular organic crystal nucleating agent. The physical properties of this injection-molded test piece were evaluated. The results of the evaluation are shown in Table 1 below, and it can be seen that the improvement of the bending temperature under load is extremely remarkable as well as the improvement of the rigidity.

Example 2 In Example 1, N, N'-dicyclohexyl-2,
A polypropylene pellet, which is a molding material, was prepared in the same manner as in Example 1 except that the addition amount of 6-naphthalene dicarboxamide was changed to 2 parts by weight. On the other hand, MFR
Blend 900 g of polypropylene for 4.7 g / 10 minutes with 100 g of this polypropylene pellets, and heat at 230 ° C.
After melt-kneading at the temperature of, pelletized to obtain pellets of polypropylene composition containing N, N'-dicyclohexyl-2,6-naphthalene dicarboxamide. Using these pellets, injection molding was performed in the same manner as in Example 1 to measure the physical properties. As shown in Table 1, it can be seen that it has a very good load deflection temperature. Further, a thin piece was cut out from the obtained injection-molded piece, stained with ruthenium tetroxide, and then observed with a transmission electron microscope to find that the acicular organic crystal nucleating agent was dispersed as in Example 1. Was confirmed.

Comparative Example 1 N, N'-dicyclohexyl-2,6-naphthalenedicarboxamide (crystal nucleating agent) was not added, except that
Pellets were obtained in the same manner as in Example 1. As a result of melting a thin piece cut out from this pellet at a temperature of 180 ° C. and observing with a polarizing microscope, nothing other than a polypropylene melt was observed. In addition, injection molding was performed using the pellets in the same manner as in Example 1 to prepare a test piece,
Physical properties were measured. Table 1 shows the results.

Comparative Example 2 Pellets were obtained in the same manner as in Example 1 except that the melt-kneading temperature was set to 230 ° C. When a thin piece cut out from this pellet was melted at a temperature of 200 ° C. and observed with a polarizing microscope, needle crystals of the organic crystal nucleating agent were not observed, and it was confirmed that the granular organic crystal nucleating agent was dispersed. (See Figure 4). Further, injection molding was carried out in the same manner as in Example 1 using the pellets to prepare test pieces, and the physical properties were measured. Table 1 shows the results. From these measurement results, it can be seen that the load deflection temperature is improved as compared with Comparative Example 1, but not as improved as in Example 1.

Comparative Example 3 Pellets were obtained in the same manner as in Example 1 except that p-t-butyl aluminum benzoate was used as the crystal nucleating agent.
When a thin piece cut out from this pellet was melted at 200 ° C. and observed with a polarization microscope, needle crystals of the organic crystal nucleating agent were not observed, and it was confirmed that the granular organic crystal nucleating agent was dispersed (FIG. 5). Also, injection molding was performed in the same manner as in Example 1 to prepare a test piece, and its physical properties were measured. Table 1 shows the results.

[0033]

[Table 1]

[0034]

According to the present invention, it is possible to produce a propylene resin composition having excellent rigidity and heat resistance, and particularly having a very high heat distortion temperature.

[Brief description of drawings]

FIG. 1 is a photograph showing a crystal structure of a nucleating agent in a propylene resin composition of Example 1 of the present invention.

FIG. 2 is a photograph showing a crystal structure of the propylene resin composition of FIG.

3 is a photograph showing the shape and dispersion structure of nucleating agent crystals in the propylene resin composition of Example 3. FIG.

FIG. 4 is a photograph showing a crystal structure of a nucleating agent in the propylene resin composition of Comparative Example 2 produced without dissolving the nucleating agent.

5 is a photograph showing a crystal structure of a nucleating agent in the propylene resin composition of Comparative Example 3. FIG.

Claims (8)

[Claims] 1. To 100 parts by weight of propylene resin,
The organic crystal nucleating agent having a needle-like shape is 0.0001 to 10
A propylene-based resin composition, characterized in that it is contained in a proportion of parts by weight. 2. The propylene resin composition according to claim 1, wherein the organic crystal nucleating agent is at least one amide compound represented by the following general formulas (1) to (3). Formula ^{R 2 -NHCO-R 1 -CONH-} R 3 (1) R 2 -CONH-R 1 -CONH-R 3 (2) R 2 -CONH-R 1 -NHCO-R 3 (3) ( in the formula , R ¹ represents a saturated or unsaturated aliphatic, alicyclic or aromatic hydrocarbon group having ¹ to 28 carbon atoms, and R ² and R ^{3 each} have ^{3 to} 18 carbon atoms which may be the same or different. Cycloalkyl group, cycloalkenyl group, embedded image Or Represents a group represented by. In the formula, R ⁴ and R ⁵ represent a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group, a cycloalkenyl group or a phenyl group, and R ⁶ and R ⁷ are carbon atoms. It represents a linear or branched alkylene group of the formulas 1 to 6. ) 3. Hydrocarbon groups R ² and R ³ of an amide compound
Is a cyclohexyl group, The propylene-based resin composition according to claim 2. 4. The propylene resin composition according to claim 3, wherein the amide compound is N, N′-dicyclohexyl-2,6-naphthalene dicarboxamide. 5. With respect to 100 parts by weight of the propylene resin,
An organic crystal nucleating agent capable of forming a needle-like shape in a propylene-based resin is mixed in a proportion of 0.0001 to 10 parts by weight, and this is melted at a temperature equal to or higher than the melting temperature of the crystal nucleating agent in a propylene-based resin melt. A method for producing a propylene-based resin composition, which comprises kneading and then cooling to contain the nucleating agent having an acicular shape. 6. The method for producing a propylene resin composition according to claim 5, wherein the organic crystal nucleating agent is at least one amide compound represented by the following general formulas (1) to (3). Formula ^{R 2 -NHCO-R 1 -CONH-} R 3 (1) R 2 -CONH-R 1 -CONH-R 3 (2) R 2 -CONH-R 1 -NHCO-R 3 (3) ( in the formula , R ¹ represents a saturated or unsaturated aliphatic, alicyclic or aromatic hydrocarbon group having ¹ to 28 carbon atoms, R ² and R ³ may be the same or different, and have 3 to 3 carbon atoms. 1
8, a cycloalkyl group, a cycloalkenyl group, and Or Represents a group represented by. In the formula, R ⁴ and R ⁵ represent a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group, a cycloalkenyl group or a phenyl group, and R ⁶ and R ⁷ are carbon atoms. It represents a linear or branched alkylene group of the formulas 1 to 6. ) 7. Hydrocarbon groups R ² and R ³ of an amide compound
Is a cyclohexyl group, The manufacturing method of the propylene resin composition of Claim 6. 8. The method for producing a propylene resin composition according to claim 6, wherein the amide compound is N, N'-dicyclohexyl-2,6-naphthalene dicarboxamide.