JP-7856839-B1 - Propylene resin composition, molded article, and method for producing a propylene resin composition

JP7856839B1JP 7856839 B1JP7856839 B1JP 7856839B1JP-7856839-B1

Abstract

[Problem] The problem is to provide a propylene-based resin composition, a molded article, and a method for producing a propylene-based resin composition that can be obtained by obtaining a molded article that has relatively reduced odor, relatively high impact strength at low temperatures, and relatively high flexibility against tensile deformation at room temperature and retention rate against tensile deformation at high temperatures. [Solution] The propylene-based resin composition according to the present invention contains a propylene-based polymer (A) and a fragrance (B), The melt flow rate is 0.3 g/10 min or more and 200 g/10 min or less. The fragrance (B) is a cyclic organic compound that does not contain nitrogen atoms and sulfur atoms. The content of the fragrance (B) is 0.01 ppm by mass or more and 1000 ppm by mass or less, relative to the propylene resin composition. [Selection Diagram] None

Inventors

樋口悠
浦野若葉

Assignees

住友化学株式会社

Dates

Publication Date: 20260511
Application Date: 20251007
Priority Date: 20250404

Claims (10)

It contains a propylene polymer (A) and a fragrance (B), The melt flow rate is 0.3 g/10 min or more and 200 g/10 min or less. The fragrance (B) is a cyclic organic compound that does not contain nitrogen atoms and sulfur atoms. The content of the fragrance (B) is 0.01 ppm by mass or more and 1000 ppm by mass or less, relative to the propylene resin composition. The propylene polymer (A) contains a heterophagic propylene polymerization material. The heterophagic propylene polymerization material comprises polymer I, which contains 97% by mass or more monomer units derived from propylene; and polymer II, which contains 50% by mass or more and 99% by mass or less monomer units derived from propylene, and 1% by mass or more and 50% by mass or less monomer units derived from at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms. The content of polymer II is 1% by mass or more and 50% by mass or less, based on 100% by mass of the total mass of the heterophagic propylene polymerization material. A propylene-based resin composition wherein the intrinsic viscosity number of polymer II is 0.1 dL/g or more and 10.0 dL/g or less .
The propylene-based resin composition according to claim 1, wherein the melt flow rate is 0.4 g/10 min or more and 90 g/10 min or less.
The propylene polymer (A) contains a propylene homopolymer, The propylene-based resin composition according to claim 1, wherein the isotactic pentad fraction of the propylene homopolymer is 0.951 or more and 0.999 or less.
The propylene polymer (A) contains a propylene random copolymer, The propylene-based resin composition according to claim 1, wherein, if the propylene random copolymer contains monomer units derived from ethylene, the content thereof is 2.9% by mass or less based on 100% by mass of the total mass of the propylene random copolymer.
The propylene-based resin composition according to claim 1, wherein the cyclic organic compound contains an oxygen atom.
The propylene-based resin composition according to claim 1, wherein the cyclic organic compound is a five-membered ring organic compound or a six-membered ring organic compound.
The propylene resin composition according to claim 1, wherein the fragrance (B) is at least one selected from the group consisting of vanillin, α-angelicalactone, trans-cinnamaldehyde, and γ-valerolactone.
The propylene-based resin composition according to claim 1, wherein the propylene-based polymer (A) is a recycled material.
A molded article comprising the propylene resin composition according to any one of claims 1 to 8 .
A method for producing a propylene resin composition according to any one of claims 1 to 8 , The process includes melting and kneading a propylene polymer (A) and a fragrance (B). A method for producing a propylene resin composition, wherein the amount of fragrance (B) blended is 0.01 ppm by mass or more and 2000 ppm by mass or less relative to the propylene polymer (A).

Description

This invention relates to a propylene-based resin composition, a molded article, and a method for producing a propylene-based resin composition. Propylene resins are widely used in automotive parts, household electrical appliance casings, and other applications due to their excellent moldability, rigidity, and heat resistance. Furthermore, in recent years, there has been a growing demand for material recycling, which involves reusing waste plastics as raw materials for plastic products. However, propylene resins contain residual components such as low molecular weight components generated during the polymerization process and components derived from polymerization catalysts. Therefore, the resulting molded products have an unpleasant odor due to these residual components. In particular, recycled propylene resins recovered from the market contain additives such as processing aids, stabilizers, fibers, and fillers, which can also contribute to the odor, resulting in even more unpleasant odors in the resulting molded products. To address the odor problem, for example, Patent Document 1 discloses a polyolefin resin composition containing a polyolefin resin, a dibenzylidene sorbitol composition, and a fragrance. It shows that the odor originating from the polyolefin resin is masked by the fragrance, such as vanillin, resulting in improved odor. International Publication No. 02/040587 The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. [Propylene resin composition] The propylene-based resin composition according to this embodiment contains a propylene-based polymer (A) and a fragrance (B). <Propylene polymer (A)> The propylene polymer (A) is a polymer containing 50% by mass or more monomer units derived from propylene. Examples of the propylene polymer (A) include propylene homopolymers, propylene random copolymers of propylene and monomers other than propylene, and heterophagic propylene polymerization materials. From the viewpoint of improving the rigidity and impact resistance of the molded article, the propylene resin composition according to this embodiment preferably contains a heterophagic propylene polymerization material as the propylene polymer (A). The propylene resin composition may contain only one type of propylene polymer (A) or two or more types. The melt flow rate (MFR) of the propylene polymer (A) is preferably 0.1 g/10 min to 300 g/10 min, more preferably 1 g/10 min to 100 g/10 min, even more preferably 5 g/10 min to 50 g/10 min, and particularly preferably 10 g/10 min to 50 g/10 min, from the viewpoint of improving the moldability of the propylene resin composition. The melt flow rate (MFR) of the propylene polymer (A) is measured by Method A, under the conditions of a temperature of 230°C and a load of 2.16 kg, according to the method specified in JIS K7210-1995. In the propylene-based resin composition according to this embodiment, the propylene-based polymer (A) may be a recycled material. A recycled material refers to a polymer that has been processed, such as by molding, or used for some final purpose, and then reused after undergoing a recovery process. The content of propylene polymer (A) is preferably 50.000% by mass or more, more preferably 75.000% by mass or more, and even more preferably 80.000% by mass or more, relative to the propylene resin composition. Furthermore, the content of propylene polymer (A) is preferably 99.995% by mass or less, and more preferably 99.900% by mass or less, relative to the propylene resin composition. (Propylene homopolymer) The propylene-based resin composition according to this embodiment may contain a propylene homopolymer as the propylene-based polymer (A). The isotactic pentad fraction of the propylene homopolymer is preferably 0.951 or higher, more preferably 0.961 or higher, even more preferably 0.965 or higher, and particularly preferably 0.970 or higher, from the viewpoint of improving rigidity. Furthermore, considering market availability, the isotactic pentad fraction of the propylene homopolymer is preferably 0.999 or lower, more preferably 0.995 or lower. In one embodiment, the isotactic pentad fraction of the propylene homopolymer is 0.951 or higher and 0.999 or lower. In this specification, the isotactic pentad fraction refers to the isotactic fraction in pentad units. That is, the isotactic pentad fraction indicates the proportion of structures in which five monomer units derived from propylene are consecutively linked by mesobonding, when viewed in pentad units. The isotactic pentad fraction is a value measured by 13C -NMR spectroscopy. Specifically, the isotactic pentad fraction is defined as the ratio of the area of the mmmm peak to the area of the total absorption peak in the methyl carbon region obtained by 13C -NMR spectroscopy. The method for measuring the isotactic pentad fraction by 13C -NMR spectroscopy is described, for example, in Macromolecules, 6, 925