JP2000265016A - Propylene resin composition and molded product therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which imparts a high melt tension, strength and rigidity to a propylene polymer, and a molded product obtained from the composition. SOLUTION: A resin composition is prepared by adding 0.01 to 4.0 pts.wt. esterified product of a polyhydric alcohol and an α,β-unsaturated carboxylic acid and 0.01 to 0.4 pts.wt. phosphorus antioxidant and/or phenolic antioxidant to 100 pts.wt. propylene polymer. Here, the above-mentioned esterified product is preferably a triester of an aliphatic polyvalent alcohol and an α,β-unsaturated carboxylic acid, especially a (meth)acrylic triester of pentaerythritol or a (meth) acrylic triester of trimethylolpropane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propylene-based resin composition and a molded article obtained therefrom, and more particularly to a propylene-based resin composition having a high melt tension and a high mechanical strength, and a molded article obtained therefrom. Molded articles.

[0002]

BACKGROUND OF THE INVENTION As one method for improving the rigidity, tensile strength, and melt tension of a propylene-based resin, a method of crosslinking the resin has been used. Specific methods for crosslinking the resin include a physical method of irradiating with ionizing radiation and a chemical method of adding an organic peroxide and a crosslinking aid.

When propylene resin is cross-linked to a desired degree of cross-linking by irradiating with ionizing radiation, it is usually necessary to irradiate a large dose due to low cross-linking efficiency, and the irradiation equipment for that is large. Therefore, it is difficult to generally adopt this method.

When the propylene-based resin is crosslinked using an organic peroxide and a crosslinking aid, the actual operation itself is simple, but a molded article considered to be caused by the organic peroxide used is used. However, the actual application range was still limited due to the generation of odor, the discoloration phenomenon of the molded article itself, and the occurrence of defects such as bumps on the molded article surface due to excessive crosslinking.

[0005] Therefore, the development of another cross-linking method that does not require a large-scale ionizing radiation irradiation facility, does not generate odor from the molded product, and does not cause discoloration or defects on the surface of the molded product. Is waiting.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a propylene resin composition which can be crosslinked by using a polyfunctional chemical crosslinking agent, and to provide a molded article obtained therefrom.

[0007]

That is, according to the present invention, an esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid is added in an amount of 0.0 to 100 parts by weight of a propylene-based polymer.
The present invention relates to a propylene-based resin composition containing 1 to 4.0 parts by weight, and 0.01 to 0.4 part by weight of a phosphorus-based antioxidant and / or a phenol-based antioxidant.

When the total amount of the phosphorus antioxidant and the phenolic antioxidant is 0.01 to 0.03, the weight ratio of the phosphorus antioxidant to the phenolic antioxidant (phosphorous antioxidant) Agent / phenolic antioxidant) is preferably adjusted to a range of 0.3 to 5.

Further, the esterified product of the polyhydric alcohol and the α, β-unsaturated carboxylic acid is preferably a triester of an aliphatic polyhydric alcohol and an α, β-unsaturated carboxylic acid. Desirably, it is a (meth) acrylic acid triester of pentaerythritol or a (meth) acrylic acid triester of trimethylolpropane.

The present invention also relates to a propylene-based polymer 100
A resin composition containing 0.01 to 0.4 parts by weight of a phosphorus-based antioxidant and / or a phenolic antioxidant was further added to 0.01 to 4.0 parts by weight with respect to parts by weight. The present invention relates to a propylene-based resin molded article which is heat-crosslinked with an esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The propylene resin composition according to the present invention comprises (a) a propylene polymer, (b) an esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid, and (c) The resin molded article according to the present invention, which comprises a phosphorus-based antioxidant and / or a phenolic antioxidant, relates to a cross-linked molded article obtained by heat-molding the resin composition. Next, each configuration of the resin composition and the resin molded body will be described in detail.

Propylene Polymer The propylene polymer used in the present invention is a propylene homopolymer having stereoregularity and a copolymer with another α-olefin. The copolymer may be a random copolymer or a block copolymer. Further, the propylene-based polymer may be used alone or in combination of two or more polymers.

The other α-olefin is an α-olefin having 2 to 20 carbon atoms other than propylene, such as ethylene, 1-butene, 1-pentene, 1-hexene,
Methyl-1-pentene, 1-heptene, 1-octene,
1-decene and the like can be exemplified. The content of the α-olefin comonomer component contained in the copolymer is 3
Up to 0% by weight, preferably up to 15% by weight, may be copolymerized.

Such a polymer can be produced using an olefin stereoregular polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. Specifically, propylene homopolymer and ethylene-propylene random copolymer are used. Polymer, 1-butene-propylene random copolymer,
Ethylene-1-butene-propylene random copolymer,
Examples include an ethylene-propylene block copolymer and the like.

The melt flow rate (MFR) of the propylene polymer suitable for molding is preferably from 0.1 to 150, more preferably from 0.1 to 150, measured at 230 ° C. under a load of 2.16 kg in accordance with ASTM D-1238. Is 1 to 100 (g / 10
Min), it is possible to achieve a high mechanical strength and a fast molding cycle, and to obtain a good molded article appearance.

Esterified Compound The esterified product used in the present invention is a polymerizable unsaturated bond obtained by carrying out an esterification reaction between a polyhydric alcohol and an α, β-unsaturated carboxylic acid. Compounds.
The compound having an unsaturated bond acts on the propylene-based polymer in a molten state to promote a crosslinking reaction, thereby increasing the melt tension of the resin composition and promoting the propylene-based polymer to form a crosslinked molded article. The esterified product preferably has at least three or more radically polymerizable unsaturated bonds in the molecule.

The polyhydric alcohol is a dihydric or higher, preferably trihydric or higher aliphatic, aromatic, alicyclic or other alcohol such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, Methylolpropane, trimethylolethane and the like can be mentioned. Among them, pentaerythritol and trimethylolpropane, which are tri- to tetravalent aliphatic alcohols, are preferably used.

Examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like. Of these, acrylic acid and methacrylic acid are preferred, and both are subsequently combined (meth)
Sometimes described as acrylic acid.

Specific examples of the esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid include pentaerythritol acrylic acid triester represented by the formula (1):
Examples include methacrylic acid triester of pentaerythritol, acrylic acid triester of trimethylolpropane represented by the formula (2), and methacrylic acid triester of trimethylolpropane.

[0020]

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[0021]

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[0022] As the phosphorus-based antioxidant which can be used oxidation prevention agent may be exemplified the following compounds. (A) triphenyl phosphite (b) triisooctyl phosphite (c) trilauryl phosphite (d) trinonyl phosphite (e) trioctadecyl phosphite (f) tridecyl phosphite (g) tristearyl phosphite

(H) trisnonylphenyl phosphite (i) tris (2,4-di-tert-butylphenyl) phosphite (j) tetrakis (2,4-di-tert-butylphenyl) 4,4-biphenyl Range phosphite (k) trilauryl dithiophosphite (l) trilauryl trithiophosphite

(M) distearyl pentaerythritol diphosphite (n) bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (o) bis (2,4-di-tert-butyl-4-methylphenyl) Pentaerythritol diphosphite

(P) bis (2,6-di-tert-butyl-
4-methylphenyl) pentaerythritol diphosphite (q) 2,2'-methylenebis (4,6-di-tert-butylphenyl) octylphosphite (r) 2-[[2,4,8,10-tetrakis (1 , 1-
Dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl] oxy] -N, N-bis [2-[[2,4,8,10-tetrakis (1, 1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl] oxy] -ethyl] ethanamine

Among these compounds, tris (2,4
-Di-tert-butylphenyl) phosphite and 2,
The use of 2'-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite is preferred.

Examples of usable phenolic antioxidants include the following compounds. (A) 2,6-di-tert-butylphenol (b) 2,6-di-tert-butyl-p-cresol (c) 2,4,6-tri-tert-butylphenol (d) 3,5-di -Tert-butyl-4-hydroxytoluene (e) 4,4'-methylene-bis (2-tert-butyl-
6-methylphenol) (f) 4,4'-methylene-bis (2,6-di-tert-
Butylphenol) (g) tetrakis [methylene-3 (3,5-di-tert-
Butyl-4-hydroxyphenyl) propionate] methane

(H) 1,3,5-trimethyl-2,4
6-tris (3,5-di-tert-butyl-4-hydroxyphenylbenzyl) benzene (i) 1,3,5-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate (J) 1,3,5-tris (4-hydroxy-3,5-
Di-tert-butylbenzyl) -s-triazine-2,
4,6- (1H, 3H, 5H) -trione

(K) n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl) propionate (l) 3,9-bis [2- {3- (3-tert -Butyl-
4-hydroxy-5-methylphenyl) propionyloxy {-1,1-dimethylethyl] 2,4,8,10-
Tetraoxaspiro [5,5] undecane

Among these compounds, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane and 1,3,5
-Tris (4-hydroxy-3,5-di-tert-butylbenzyl) -s-triazine-2,4,6- (1H, 3
The use of (H, 5H) -trione is preferred.

If necessary, a sulfur-based antioxidant may be further combined and blended, and examples thereof include the following sulfur compounds. (A) distearylthiodipropionate (b) dilaurylthiodipropionate (c) dimyristyl-3,3'-thiodipropionate (d) penta (erythrityl-tetra-β-mercaptolauryl) propionate

[0032] In the resin composition according to the tree fat group formed product present invention, with respect to the propylene-based polymer to 100 parts by weight of a polyhydric alcohol and alpha, beta-
The esterified product with the unsaturated carboxylic acid is 0.01 to 4.0.
Parts by weight, preferably 0.02 to 2.0 parts by weight, and when the amount is within this range, the crosslinking between the propylene-based polymer molecules by the esterified compound proceeds efficiently, and as a result, the tension of the molten resin increases. And the molded body is easily formed, and the tensile strength and rigidity of the molded body are improved.

Further, the phosphorus-based antioxidant and / or the phenol-based antioxidant are used in an amount of 0.01 to 0.4 part by weight, preferably 0.1 part by weight, per 100 parts by weight of the propylene-based polymer.
It is blended in an amount of 02 to 0.2 parts by weight. When it is within this range, the tension of the molten resin is increased and molding is facilitated.

When the amount of the antioxidant is small, the combined use of the phosphorus-based antioxidant and the phenol-based antioxidant
Further enhance the antioxidant effect. In particular, the total amount of the phosphorus-based antioxidant and the phenol-based antioxidant is 0.01%.
When it is from 0.03 to 0.03, the weight ratio of the phosphorus-based antioxidant to the phenol-based antioxidant (phosphorus-based antioxidant / phenol-based antioxidant) is from 0.3 to 5, preferably from 0.5 to 5.
It is desirably 2. When the total amount of the phosphorus antioxidant and the phenolic antioxidant is 0.03 to 0.4 parts by weight, the weight ratio of the phosphorus antioxidant to the phenolic antioxidant is not particularly limited.

The resin composition contains a weathering stabilizer, an ultraviolet absorber, a nucleating agent, and the like within a range not to impair the object of the present invention.
Various commonly used additives such as a lubricant, a flame retardant, an antiblocking agent, a hydrochloric acid absorbent, a coloring agent, and a filler can be blended. Further, if necessary, a rubber or elastomeric polymer, or a polymer called a resin modifier, for example, an ethylene-propylene copolymer, an ethylene-1-butene copolymer, etc. It can be appropriately blended within the range.

A mixture obtained by mixing the above-mentioned various compounding agents with the propylene-based polymer is mixed with a Henschel mixer, an extruder,
Using a mixing device such as a Banbury mixer, a tumbler, a Brabender, a kneader, a ribbon blender, etc., the mixture is uniformly mixed to obtain a resin composition. Since the resin composition is often melt-kneaded and pelletized, the propylene-based polymer substantially undergoes crosslinking at the resin temperature at that time, for example, 170 to 250 ° C.

The formed shape member according to the present invention the resin molded body, at the resin composition in molding conditions, blow molding, injection molding, extrusion molding, by means such as expansion molding, the molded article of various shapes It is shaped. In the resin composition, an esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid acts as a cross-linking agent at the time of melt extrusion such as the above-mentioned pelletizing step, and the molten resin is raised to a tension that facilitates molding. Therefore, molding can be easily performed with the high melt tension, and the molded body has a cross-linked three-dimensional structure.

[0038]

EXAMPLES Next, the present invention will be described through examples and comparative examples, but the present invention is not limited to these examples. The following products were used for the propylene polymer, esterified product, organic peroxide, and antioxidant used here. (1) Propylene polymer: Grand Polymer Co., Ltd. Brand name Grand Polypro J105 MFR10
(2) Esterified product: pentaerythritol triacrylate (3) Organic peroxide: 1,3-bis (tert-butylperoxyisopropyl) benzene (4) Phenolic antioxidant: Tetrakis [methylene -3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane (5) Phosphorus antioxidant: tetrakis (2,4-di-te
rt-butylphenyl) phosphite

Next, the molded articles were evaluated by the following test methods, and the results are shown in Table 1. (1) Tensile test: 2 in accordance with ASTM D638
The test was performed at 3 ° C. under the condition of a tensile speed of 30 mm / min. (2) Flexural modulus: 2 according to ASTM D790
The bending was performed at 3 ° C. at a bending speed of 30 mm / min. (3) Melt tension: Measured under the conditions of a nozzle diameter of 2.1 mm, a nozzle length of 8.0 mm, a temperature of 190 ° C., and a speed of 15 m / min. (4) The spots (defects) and discoloration on the surface of the molded product were visually determined by judging the molded product. (5) The odor of the molded article was evaluated by sensory evaluation of the molded article. When the odor was not sensed, it was indicated by ○, and when the odor was sensed, it was indicated by X.

Examples 1 to 5 Propylene polymer 10
The esterified compound, the phenolic antioxidant, and the phosphorus-based antioxidant were mixed with each other in an amount of 0 parts by weight as shown in Table 1 and melt-kneaded at a temperature of 230 ° C. to form pellets. Next, the pellet was injection-molded at a temperature of 230 ° C., and an ASTM-IV tensile test piece, ASTM-IV
A bending test piece of D-790 and a sheet molded body having a thickness of 2 mm were obtained. Various physical properties tests were performed using the sheet, and the test results are shown in Table 1.

(Comparative Examples 1 to 3) Propylene polymer 10
The procedure was performed in the same manner as in Example 1, except that the esterified compound, the organic peroxide, the phenolic antioxidant, and the phosphorus-based antioxidant were each mixed in the proportions shown in Table 1 with respect to 0 parts by weight. . Thereafter, various physical property tests were performed, and the test results are also shown in Table 1.

[0042]

[Table 1]

As is clear from the results in Table 1, Example 1
The resin compositions used in Nos. 5 to 5 have a high melt tension, so they are easy to mold, and have high tensile strength and flexural modulus, so they are excellent in mechanical strength and rigidity. You can see that it is. No defects or discoloration were observed on the surface of the molded product, and no odor was observed.

On the other hand, when the esterified compound was not blended (Comparative Example 1), the melt tension was small, indicating that molding was difficult. In addition, even if the esterified compound is blended, if the blending amount of the antioxidant is too large (Comparative Example 2), the crosslinking does not proceed and the tensile strength, the tensile modulus and the melt tension are not improved. When an organic peroxide was used in combination with the esterified product (Comparative Example 3), the molded article had an odor, and surface defects and discoloration were recognized, indicating that it was not a practical molded article.

[0045]

In the resin composition according to the present invention, an esterified product of a polyhydric alcohol and an .alpha.,. Beta.-unsaturated carboxylic acid acts as a polyfunctional crosslinking agent. The propylene-based resin could be easily cross-linked under the conditions of heating and kneading without installing equipment, and as a result, the melt tension increased and the resin could be changed to a resin that was easy to mold.

Further, as a result of the resin composition according to the present invention being crosslinked, the tensile strength and rigidity of the molded article are improved, and the appearance of the molded article surface is good, and no odor is felt. It can be suitably used in a wide range of fields, including industrial supplies. Examples of such a molded article include a hollow body, an injection molded article, a foam molded article, a sheet, a film, a pipe, and a fiber. In particular, the application could be expanded to fields that could not be used until now, such as high-magnification foam molded articles.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akihiro Inukai 3 Chigusa Beach, Ichihara-shi, Chiba Prefecture Within Grand Polymer Co., Ltd. (72) Inventor Kei Takada 3-1-1 Chikushinmachi, Sakai-shi, Osaka Grand Polymer Co. F term (reference) 4J002 BB121 BB141 BB151 BP021 EH076 EJ017 EJ027 EJ037 EJ047 EU197 EW067 EW087 FD077 FD146

Claims (7)

[Claims] 1. An esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid in an amount of 0.01 to 4.0 parts by weight, based on 100 parts by weight of a propylene polymer, and a phosphorus-based antioxidant and And / or a phenolic antioxidant of 0.
A propylene-based resin composition, which is contained in an amount of from 0.01 to 0.4 parts by weight. 2. When the total amount of the phosphorus antioxidant and the phenolic antioxidant is 0.01 to 0.03 parts by weight, the weight ratio of the phosphorus antioxidant to the phenolic antioxidant (phosphorous antioxidant) The propylene-based resin composition according to claim 1, wherein the ratio of (system-based antioxidant / phenol-based antioxidant) is 0.3 to 5. 3. The method according to claim 1, wherein the propylene polymer is a propylene homopolymer, an ethylene-propylene random copolymer,
Ethylene-1-butene-propylene random copolymer,
The propylene-based resin composition according to claim 1, wherein the propylene-based resin composition is at least one polymer selected from the group consisting of an ethylene-propylene block copolymer. 4. An esterified product of the polyhydric alcohol and an α, β-unsaturated carboxylic acid is a triester of an aliphatic polyhydric alcohol and an α, β-unsaturated carboxylic acid. The propylene-based resin composition according to claim 1. 5. The esterified product of the polyhydric alcohol and the α, β-unsaturated carboxylic acid is a (meth) acrylic acid triester of pentaerythritol or a (meth) acrylic acid triester of trimethylolpropane. The propylene-based resin composition according to any one of claims 1 to 3, wherein: 6. A resin composition containing 0.01 to 0.4 parts by weight of a phosphorus-based antioxidant and / or a phenol-based antioxidant with respect to 100 parts by weight of a propylene-based polymer. A propylene-based resin molded article which is heat-crosslinked by an esterified product of a polyhydric alcohol and an α, β-unsaturated carboxylic acid, which is added in an amount of from 0.01 to 4.0 parts by weight. 7. The esterified product of the polyhydric alcohol and the α, β-unsaturated carboxylic acid is pentaerythritol (meth) acrylate triester or trimethylolpropane (meth) acrylate triester. The propylene-based resin molded product according to claim 6, wherein: