JP7734542B2 - Oxazoline-modified polypropylene - Google Patents

Description

The present invention relates to oxazoline-modified polypropylene, a method for producing the same, and a polypropylene composition containing the oxazoline-modified polypropylene.

Automotive components are made of polypropylene compositions, and to improve the mechanical strength of these components, components made of compositions in which polypropylene is mixed with a filler are used. Fillers used include carbon fiber, glass fiber, and talc. Furthermore, when mixing polypropylene with the filler, a coupling agent or polypropylene modified with a specific polar group is used.
For example, in International Publication No. 2016/188886 (Patent Document 1), tensile modulus and tensile strength are improved by using a composition containing polypropylene, carbon fiber, and polypropylene grafted with maleic anhydride as a coupling agent.

International Publication No. 2016/188886

The present invention aims to solve the problem of providing a substance that is useful for improving the mechanical strength of fiber-reinforced polypropylene compositions.

The present inventors have discovered the present invention by focusing on 1) the fact that modified polypropylene is useful for improving the mechanical strength of a fiber-reinforced polypropylene composition, 2) the use of oxazoline-modified polypropylene as the modified polypropylene, 3) the content of oxazoline groups in the oxazoline-modified polypropylene, and 4) the melt mass-flow rate (MFR) of the oxazoline-modified polypropylene.
The present inventors also focused on 5) melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and 6) adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture to discover the present invention.

The present invention relates to, but is not limited to, the following:
[Invention 1]
Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2):
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1×10 ⁻² to 100×10 ⁻² mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min.
[Invention 2]
1. An oxazoline-modified polypropylene produced by a process comprising the steps of:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.
[Invention 3]
A method for producing oxazoline-modified polypropylene, comprising the following steps:
A step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride;
A step of adding an oxazoline compound to the melt-kneaded mixture of the obtained polypropylene, organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.
[Invention 4]
A polypropylene composition comprising (component 1):
(Component 1) Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2):
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1×10 ⁻² to 100×10 ⁻² mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min.
[Invention 5]
A polypropylene composition comprising (component 1):
(Component 1) Oxazoline-modified polypropylene produced by a process comprising the following steps:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.
[Invention 6]
A polypropylene composition according to Invention 4 or 5, containing 1 to 20% by mass of (Component 1), and the following (Component 2) and (Component 3):
(Component 2) Polypropylene: content of 30 to 98 mass %, and (Component 3) at least one filler selected from the group consisting of carbon fiber, glass fiber, and talc: content of 1 to 50 mass %.
[Invention 7]
(Component 3) The polypropylene composition according to any one of Inventions 4 to 6, which contains carbon fiber as a filler.

By incorporating the characteristics of the present invention into the oxazoline-modified polypropylene, we have succeeded in improving the mechanical strength of a polypropylene composition containing the oxazoline-modified polypropylene and a filler, as well as a molded article containing the composition.

DEFINITIONS All numbers disclosed herein are approximations, whether or not the word "about" or "approximately" is used in conjunction with it. They may vary by 1 percent, 2 percent, 5 percent, or sometimes 10 to 20 percent. Whenever a numerical range with a lower limit, R ^L , and an upper limit, R ^U , is disclosed, any number falling within the range is specifically disclosed. Specifically, the following numbers within the range are specifically disclosed: R = R ^L + k ^* (R ^U - ^{R L} ), where k is a variable ranging from 1 percent to 100 percent in 1 percent increments, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, ..., 50 percent, 51 percent, 52 percent, ..., 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Additionally, any numerical range defined by two R numbers as set forth above is also specifically disclosed.

When expressing a numerical range, the expression "lower limit to upper limit" means "greater than or equal to the lower limit, less than or equal to the upper limit," while the expression "upper limit to lower limit" means "less than or equal to the upper limit, greater than or equal to the lower limit." In other words, these expressions represent a numerical range that includes both the lower limit and the upper limit.

Several embodiments of the present invention are described in detail below. However, the present invention is not limited to the following embodiments.

Oxazoline-modified polypropylene "Oxazoline-modified polypropylene" means polypropylene modified with an oxazoline compound, and has an oxazoline group.
The oxazoline-modified polypropylene of the present invention satisfies the following requirements (1), (1-a), and (2):
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1×10 ⁻² to 100×10 ⁻² mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min.

The above "oxazoline group" may refer to the oxazoline group itself, or to an oxazoline group in which the ring is opened. The oxazoline group may have a substituent.

As described above, the content of oxazoline groups per 1 g of oxazoline-modified polypropylene is in the range of 0.1×10 ⁻² to 100× ^{10 −2} mmol/g, with the lower limit of this range preferably being 1.0×10 ⁻² mmol/g, more preferably 2.5×10 ⁻² mmol/g, and the upper limit of this range preferably being 25×10 ⁻² mmol/g, more preferably 17×10 −2 mmol/g. The range is preferably 1.0×10 ⁻² to 25×10 ⁻² mmol/g, more preferably 2.5×10 ⁻² to 17×10 ⁻² mmol/g.

The oxazoline group content per 1 g of oxazoline-modified polypropylene can be determined by infrared (IR) spectroscopy. For example, when oxazoline-modified polypropylene is produced by modifying maleic anhydride-modified polypropylene with an oxazoline compound, the content can be determined by the method described in the Examples.

As mentioned above, the melt mass flow rate of the oxazoline-modified polypropylene is in the range of 0.01 to 300 g/10 min, preferably 0.1 to 300 g/10 min, and more preferably 0.8 to 180 g/10 min.

The above "melt mass-flow rate" refers to the melt mass-flow rate measured at a temperature of 230°C and a load of 2.16 kg according to the method specified in JIS K 7210.

Method for Producing Oxazoline-Modified Polypropylene The oxazoline-modified polypropylene of the present invention may be produced by a method comprising the following steps:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.
Furthermore, polypropylene and/or at least one filler may be contained during the production of the oxazoline-modified polypropylene of the present invention.

Oxazoline Compounds Examples of oxazoline compounds include compounds of formula 1 having two oxazoline groups.

R ¹ represents a divalent organic group, for example,
alkylene groups such as a methylene group (-CH ₂ -), an ethylene group (-CH ₂ CH ₂ -), and a propylene group (-CH ₂ CH ₂ CH ₂ -);
alkenylene groups such as ethenylene group (-CH=CH-) and propenylene group (-CH=CH-CH ₂ -);
phenylene groups such as a 1,2-phenylene group, a 1,3-phenylene group, or a 1,4-phenylene group;

etc.

The above-mentioned kneading method is not particularly limited, but examples include a method in which polypropylene, organic peroxide, maleic acid or maleic anhydride, and oxazoline compound are simultaneously or sequentially fed into, for example, a Henschel mixer, V-type blender, tumbler blender, ribbon blender, or the like, and kneaded, and then melt-kneaded using a single-screw extruder, multi-screw extruder, kneader, Banbury mixer, or the like. Among these, the use of equipment with excellent kneading performance, such as a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer, is preferred, as it allows the components to be dispersed more uniformly.

The polypropylene, the organic peroxide, the maleic acid or maleic anhydride, and the oxazoline compound are fed to the extruder in the following manner:
1) A method in which an extruder is equipped with three hoppers, and polypropylene is supplied from the first hopper along the resin flow, an organic peroxide and maleic acid or maleic anhydride are supplied together from the second hopper, and an oxazoline compound is supplied from the third hopper;
2) A method in which an extruder is equipped with two hoppers, and polypropylene, an organic peroxide, and maleic acid or maleic anhydride are supplied together from the first hopper along the resin flow, and an oxazoline compound is supplied from the second hopper;
3) A method in which an extruder is equipped with two hoppers, and polypropylene, an organic peroxide, and maleic acid or maleic anhydride are supplied together through the first hopper along the resin flow, and an organic peroxide, an oxazoline compound, and maleic acid or maleic anhydride are supplied together through the second hopper;
Either of the above methods can be adopted.

When melt-kneading the above components, it is preferable to melt-knead each component at a temperature equal to or higher than the highest melting point of the components being mixed. Specifically, melt-kneading is preferably performed in the range of 120 to 300°C, more preferably 180 to 280°C, and even more preferably 200 to 270°C.

Polypropylene composition The polypropylene composition of the present invention comprises:
It contains the oxazoline-modified polypropylene of the present invention (sometimes referred to as "component 1").
The polypropylene composition of the present invention may contain at least one component selected from the group consisting of polypropylene (sometimes referred to as "component 2"), a filler (sometimes referred to as "component 3"), and another modified polypropylene (sometimes referred to as "component 4").
In one embodiment, the polypropylene composition of the present invention contains "Component 2" and "Component 3." In one embodiment, the polypropylene composition may further contain "Component 4."

Polypropylene (component 2)
Examples of polypropylene (component 2) include:
propylene homopolymer,
propylene-ethylene random copolymer,
propylene-α-olefin random copolymer,
propylene-ethylene-α-olefin copolymer,
A heterophasic propylene polymer material comprising a propylene homopolymer component or a copolymer component mainly composed of propylene (hereinafter also referred to as polymer component I), and a copolymer obtained by copolymerizing propylene with at least one monomer selected from ethylene and an α-olefin (hereinafter also referred to as polymer component II).
These polypropylenes may be used alone or in combination of at least two kinds.

Preferred α-olefins used in the production of component 2 include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and more preferably 1-butene, 1-hexene, and 1-octene.

Examples of the propylene-α-olefin random copolymer include propylene-1-butene random copolymer, propylene-1-hexene random copolymer, and propylene-1-octene random copolymer.

Examples of the propylene-ethylene-α-olefin copolymer include propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, and propylene-ethylene-1-octene copolymer.

The ethylene or α-olefin content in the propylene-ethylene random copolymer, propylene-α-olefin random copolymer, and propylene-ethylene-α-olefin copolymer is typically 0.01 to 30% by weight, and preferably 0.1 to 20% by weight, where the total amount of the copolymer is taken as 100% by weight.

When polymer component I of the heterophasic propylene polymer material is a copolymer component mainly composed of propylene, polymer component I contains at least one olefin selected from ethylene and α-olefins having 4 to 12 carbon atoms, and the content thereof is typically 0.01 to 30% by weight. However, the total amount of polymer component I is taken as 100% by weight.

When the polymer component I is a copolymer component mainly composed of propylene, examples include a propylene-ethylene copolymer component, a propylene-1-butene copolymer component, and a propylene-1-hexene copolymer component.

Examples of the polymer component II of the heterophasic propylene polymer material include a propylene-ethylene copolymer component, a propylene-ethylene-1-butene copolymer component, a propylene-ethylene-1-hexene copolymer component, a propylene-ethylene-1-octene copolymer component, a propylene-1-butene copolymer component, a propylene-1-hexene copolymer component, and a propylene-1-octene copolymer component.

The content of at least one olefin selected from ethylene and α-olefins having 4 to 12 carbon atoms contained in polymer component II is typically 1 to 80% by weight, preferably 20 to 70% by weight, and more preferably 30 to 60% by weight. However, the total amount of polymer component II is taken as 100% by weight.

The content of polymer component II in the heterophasic propylene polymer material is typically 1 to 70% by weight, preferably 5 to 50% by weight, and more preferably 10 to 40% by weight. However, the total amount of the heterophasic propylene polymer material is taken as 100% by weight.

Examples of heterophasic propylene polymer materials comprising the polymer component I and the polymer component II include the following:
(propylene)-(propylene-ethylene) polymeric materials,
(propylene)-(propylene-ethylene-1-butene) polymeric materials,
(propylene)-(propylene-ethylene-1-hexene) polymeric materials,
(propylene)-(propylene-1-butene) polymeric materials,
(propylene)-(propylene-1-hexene) polymeric materials,
(propylene-ethylene)-(propylene-ethylene) polymeric materials,
(propylene-ethylene)-(propylene-ethylene-1-butene) polymeric materials,
(propylene-ethylene)-(propylene-ethylene-1-hexene) polymeric materials,
(propylene-ethylene)-(propylene-1-butene) polymeric materials,
(propylene-ethylene)-(propylene-1-hexene) polymeric materials,
(propylene-1-butene)-(propylene-ethylene) polymeric materials,
(propylene-1-butene)-(propylene-ethylene-1-butene) polymer materials,
(propylene-1-butene)-(propylene-ethylene-1-hexene) polymeric materials,
(propylene-1-butene)-(propylene-1-butene) polymer materials,
(Propylene-1-butene)-(propylene-1-hexene) polymer material.

Filler (component 3)
Examples of fillers (component 3) include the following:

Carbon fiber (component 3-1)
As the carbon fiber (component 3-1), various conventionally known carbon fibers can be used, including polyacrylonitrile-based, rayon-based, pitch-based, polyvinyl alcohol-based, regenerated cellulose-based, and pitch-based carbon fibers produced from mesophase pitch.
Furthermore, recycled carbon fibers can be used as the carbon fibers (component 3-1). Specifically, recycled carbon fibers can be used that are obtained by burning carbon fibers used in aircraft and the like.

The fiber diameter of component 3-1 is not particularly limited, but is preferably 3 μm or more, more preferably 8 μm or more, to strengthen the fibers, improve productivity of reinforcing fiber bundles, reduce the effort required to connect fiber bundles during continuous pellet production, and improve productivity. Furthermore, to improve the fiber aspect ratio when the pellet length is fixed, the fiber diameter is preferably 30 μm or less, more preferably 20 μm or less.

The aspect ratio of component 3-1 is not particularly limited, but to strengthen the fibers, a ratio of 5 or more is preferable. Furthermore, to improve moldability, the aspect ratio is preferably 6000 or less. The aspect ratio of component 3-1 can be calculated from the average fiber diameter and average fiber length by dividing the average fiber length by the average fiber diameter.

The raw material for component 3-1 is a continuous fiber bundle, which is commercially available as a tow. Typically, the average fiber diameter is 3 to 30 μm, and the number of filaments in the bundle is 500 to 24,000. Preferably, the average fiber diameter is 4 to 10 μm, and the number of filaments in the bundle is 6,000 to 15,000.

Alternatively, chopped strands can also be used as component 3-1. The length of these chopped strands is typically 1 to 20 mm, with a fiber diameter of approximately 3 to 30 μm, preferably 4 to 10 μm.

The fiber length of component 3-1 constituting the polypropylene composition of the present invention is typically 0.05 to 200 mm, preferably 0.2 to 50 mm, and more preferably 4 to 20 mm.

The average aspect ratio (fiber length/fiber diameter) is typically 5 to 6,000, preferably 10 to 3,000, and more preferably 15 to 2,000.

The surface of component 3-1 may be treated by oxidation etching or coating. Examples of oxidation etching treatments include air oxidation treatment, oxygen treatment, treatment with an oxidizing gas, treatment with ozone, corona treatment, flame treatment, (atmospheric pressure) plasma treatment, and oxidizing liquids (nitric acid, aqueous solutions of alkali metal hypochlorite, potassium dichromate-sulfuric acid, potassium permanganate-sulfuric acid). Examples of materials that can be used to coat carbon fibers include carbon, silicon carbide, silicon dioxide, silicon, plasma monomers, ferrocene, and iron trichloride.

If necessary, sizing agents such as urethane-based, olefin-based (such as polypropylene), acrylic-based, nylon-based, butadiene-based, epoxy-based (including special epoxies), and polyester-based may also be used.

Carbon Fiber Surface The carbon fiber (component 3-1) that may be contained in the polypropylene composition of the present invention may contain predetermined amounts of C-O bonds, C=O bonds, O-C=O bonds, C-C bonds, and C-N bonds on its surface so as to increase the mechanical strength of the polypropylene composition. Note that in all of the above and below embodiments, "C-O bond" does not include the C-O bond in "O-C=O bond," and "C=O bond" does not include the C=O bond in "O-C=O bond."

In one embodiment, component 3-1 contains a C-O bond, a C=O bond, an O-C=O bond, a C-C bond, and a C-N bond, and the C-O bond content is in the range of 1 to 24%, preferably 3 to 20%, and more preferably 5 to 15%, where the sum of the spectral areas of the C-O bond, C=O bond, O-C=O bond, C-C bond, and C-N bond is 100%.

In one embodiment, component 3-1 contains a C-O bond, a C=O bond, an O-C=O bond, a C-C bond, and a C-N bond, and the total content of C=O bonds and O-C=O bonds is in the range of 4 to 15%, preferably 5 to 12%, and more preferably 5 to 8%, where the total of the spectral areas of the C-O bond, C=O bond, O-C=O bond, C-C bond, and C-N bond is 100%.

In one embodiment, component 3-1 contains a C-O bond, a C=O bond, an O-C=O bond, a C-C bond, and a C-N bond, and the total of the spectral areas of the C-O bond, C=O bond, O-C=O bond, C-C bond, and C-N bond is taken as 100%, and the C-O bond content is in the range of 5 to 24%, preferably 3 to 20%, and more preferably 5 to 15%, and the total of the C=O bond and O-C=O bond content is in the range of 4 to 15%, preferably 5 to 12%, and more preferably 5 to 8%.

Calculation method for bonded components on the carbon fiber surface The bonded amount of each component on the carbon fiber surface can be measured by an X-ray photoelectron spectroscopy device. If necessary, pretreatment such as removing unreacted sizing agent may be performed before the measurement.
As an excitation source, characteristic X-rays such as monochromated Al Kα rays (1486.6 eV) or Mg Kα rays (1253.6 eV) can be used.
The resulting spectrum can be separated into individual bands using known methods.
For example, the amount of each bond component on the surface of the carbon fiber can be calculated by the method described in the Examples.

Glass fiber (component 3-2)
The polypropylene composition of the present invention may contain glass fibers (component 3-2).
The glass fiber used is not particularly limited. Examples of the type of glass used for the fiber include E-glass, C-glass, A-glass, and S-glass, among which E-glass is preferred. The method for producing the glass fiber is not particularly limited, and it can be produced by various known production methods.
Two or more types of glass fibers may be used in combination.

The fiber diameter of the glass fiber is not particularly limited, but is typically 3 to 25 μm. The fiber length of the glass fiber is not particularly limited, but is typically 0.1 to 20 mm.

The glass fibers may be treated with a sizing agent and/or a surface treatment agent. Treatment with a sizing agent allows the glass fibers to be bound together.

The glass fibers are preferably surface-treated with a surface treatment agent to improve dispersibility in polypropylene (component 2). Examples of surface treatment agents include organic silane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, silicone compounds, higher fatty acids, fatty acid metal salts, and fatty acid esters.

Examples of organic silane coupling agents include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane.

Examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctylpyrophosphate) titanate, and isopropyl tri(N-aminoethyl) titanate.

An example of an aluminate coupling agent is acetoalkoxyaluminum diisopropylate.

Examples of zirconate coupling agents include tetra(2,2-diallyloxymethyl)butyl, di(tridecyl)phosphite zirconate, and neopentyl(diallyl)oxytrineodecanoyl zirconate.

Examples of silicone compounds include silicone oil and silicone resin.

Examples of higher fatty acids include oleic acid, capric acid, lauric acid, palmitic acid, stearic acid, montanic acid, linoleic acid, rosin acid, linolenic acid, undecanoic acid, and undecenoic acid.

Examples of higher fatty acid metal salts include sodium salts, lithium salts, calcium salts, magnesium salts, zinc salts, and aluminum salts of fatty acids having 9 to 30 carbon atoms (e.g., stearic acid, montanic acid). Of these, calcium stearate, aluminum stearate, calcium montanate, and sodium montanate are preferred.

Examples of fatty acid esters include esters of fatty acids having 9 to 30 carbon atoms, and more specifically, include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, alpha sulfo fatty acid esters, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyethylene fatty acid esters, and sucrose fatty acid esters.

There are no particular restrictions on the amount of surface treatment agent used. The amount of surface treatment agent used is preferably 0.01 to 5 parts by weight, and more preferably 0.1 to 3 parts by weight, per 100 parts by weight of glass fiber.

Examples of sizing agents include epoxy-based sizing agents, aromatic urethane-based sizing agents, aliphatic urethane-based sizing agents, acrylic-based sizing agents, and maleic anhydride-modified polyolefin-based sizing agents.

The sizing agent is preferably one that melts at the temperature used in the production process of the polypropylene composition, and more preferably one that melts at 200°C or below.

Chopped strands, which are obtained by cutting glass strands, may also be used as glass fibers.

Resin pellets containing glass fibers (glass fiber-containing resin pellets) may be used as the glass fibers. In such glass fiber-containing pellets, the length of the glass fibers (fiber length) typically roughly matches the length of the glass fiber-containing resin pellets in the extrusion direction.

Glass fiber-containing resin pellets can be produced by any suitable conventional manufacturing method using any suitable conventional resin selected taking into consideration the composition of the polypropylene composition to be produced.

Glass fiber-containing resin pellets can be produced, for example, by the pultrusion molding method. The pultrusion molding method involves pulling out multiple continuous glass fibers while melt-extruding any suitable conventional resin, which is the material for glass fiber-containing resin pellets, from an extruder to impregnate the glass fiber bundles with the resin. The resin-impregnated glass fiber bundles are then cooled and cut using a pelletizer to integrate the multiple glass fiber bundles.

The glass fiber content in the glass fiber-containing resin pellets is preferably 50 to 99.9% by mass.

Glass fibers that have a water-soluble base content of 0.1 mmol/g or less and a water-soluble weak acid salt content of 0.1 mmol/g or less can be selected from commercially available products and used. Specific examples of commercially available products include "CS-249A-10C" (trade name, manufactured by Owens Corning Co., Ltd.), "ECS10-03-508H" (trade name, manufactured by Kyoseki JAPAN Co., Ltd.), and "T480H" (product number, manufactured by Nippon Electric Glass Co., Ltd.).

Talc (ingredient 3-3)
The propylene composition of the present invention may contain talc (component 3-3), which is a silicate mineral.

The propylene composition of the present invention may contain only one type of talc, or may contain two or more types of talc.

The shape of the talc may be plate-like, needle-like, or fibrous. From the viewpoint of the rigidity, impact resistance, and dimensional stability of the molded product, plate-like talc is more preferred.

From the viewpoints of rigidity, impact resistance, and dimensional stability of the molded article, the average particle diameter D50[L] of talc is preferably 20.0 μm or less, and more preferably 15.0 μm or less. The average particle diameter D50[L] of talc may be 2.0 μm or more, or may be 4.0 μm or more. The average particle diameter D50[L] of Component C is preferably 2.0 to 20.0 μm, and more preferably 4.0 to 15.0 μm.
The average particle size D50[S] of the talc is preferably 5.0 μm or less, more preferably 3.0 μm or less, from the viewpoint of the rigidity, impact resistance and dimensional stability of the molded article.
The average particle diameter D50[S] of Component C may be 0.5 μm or more, or may be 1.0 μm or more. The average particle diameter D50[S] of Component C is preferably 0.5 to 5.0 μm, and more preferably 1.0 to 3.0 μm.
The ratio of the average particle diameter D50[L] to the average particle diameter D50[S] of talc (D50[L]/D50[S]) may be 1.5 or more, or 2.5 or more, from the viewpoint of rigidity and dimensional stability of the molded body. D50[L]/D50[S] may be 10 or less, or 8 or less. D50[L]/D50[S] may be 1.5 to 10, 1.5 to 8, 2.5 to 10, or 2.5 to 8.

The "average particle diameter D50[L]" is determined based on volume-based particle diameter distribution measurement data measured by laser diffraction in accordance with the method specified in JIS R1629, and means the particle diameter when the cumulative number of particles from the smaller particle diameter side reaches 50% (50% equivalent particle diameter) in the particle diameter distribution measurement data. The particle diameter defined in this way is generally called the "50% equivalent particle diameter" and is expressed as "D50".
In this specification, the term "average particle diameter D50 [S]" is determined based on volume-based particle diameter distribution measurement data measured by centrifugal sedimentation in accordance with the method specified in JIS R1619, and refers to the particle diameter when the cumulative number of particles from the smaller particle diameter side reaches 50% in the particle diameter distribution measurement data (50% equivalent particle diameter).

Other modified polypropylene (component 4)
The propylene composition of the present invention may further contain a modified polypropylene other than the oxazoline-modified polypropylene (component 1).
The other modified polypropylene (component 4) is not particularly limited as long as it is polypropylene modified to impart polarity, and examples thereof include polypropylene modified with (anhydrous) carboxylic acid, epoxy, isocyanate, carbodiimide, etc., and oxazoline-modified polypropylene that does not satisfy the conditions of component 1, and preferred examples include maleic anhydride-modified polypropylene, carbodiimide-modified polypropylene, and epoxy-modified polypropylene.

Maleic anhydride modified polypropylene (polypropylene MM)
Examples of the maleic anhydride-modified polypropylene (sometimes referred to as polypropylene MM) as component 4 include the following 1 to 4:
1. Modified polypropylene obtained by graft polymerizing an unsaturated carboxylic acid and/or its derivative onto a propylene homopolymer;
2. Modified polypropylene obtained by graft polymerizing an unsaturated carboxylic acid and/or its derivative onto a propylene copolymer consisting of at least two types of monomers;
3. Modified propylene obtained by homopolymerizing propylene and then copolymerizing at least two kinds of olefins to obtain a block copolymer, and then graft-polymerizing an unsaturated carboxylic acid and/or a derivative thereof;
4. Modified polypropylene obtained by random copolymerization or block copolymerization of propylene, optionally at least one olefin, and an unsaturated carboxylic acid and/or a derivative thereof.

Polypropylene MM can be produced using a variety of methods, including those described in "Practical Polymer Alloy Design" (Ide Fumio, Kogyo Chosakai (1996)), Prog. Polym. Sci., 24, 81-142 (1999), and JP 2002-308947 A. That is, any of the solution method, bulk method, and melt-kneading method may be used. These methods may also be used in combination.

Examples of unsaturated carboxylic acids used in the production of polypropylene MM include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Derivatives of unsaturated carboxylic acids include acid anhydrides, ester compounds, amide compounds, imide compounds, and metal salts derived from the unsaturated carboxylic acids. Specific examples include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, acrylamide, methacrylamide, monoamide maleate, diamide maleate, monoamide fumarate, maleimide, N-butylmaleimide, and sodium methacrylate. Compounds that dehydrate to produce an unsaturated carboxylic acid during graft polymerization onto polypropylene, such as citric acid and malic acid, may also be used.
The unsaturated carboxylic acid and/or its derivative is preferably a glycidyl ester of acrylic acid, methacrylic acid, or maleic anhydride.

Organic peroxides used in the production of polypropylene MM include, for example, dicetyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis(4-tert-butyl cyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butylperoxyisopropyl carbonate, dimyristyl peroxycarbonate, 1,1,3,3-tetramethylbutyl neodecanoate, α-cumylperoxyneodecanoate, tert-butylperoxyneodecanoate, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(tert-butylperoxy)cyclododecane, tert-hexylperoxyisopropyl monocarbonate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxylaurate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butylperoxyacetate, 2,2-bis(t Examples of suitable peroxyl groups include tert-butylperoxybutene, tert-butyl peroxybenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, di-tert-butylperoxyisophthalate, dicumyl peroxide, α-α'-bis(tert-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxydiisopropyl)benzene, tert-butylcumyl peroxide, di-tert-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, and bis(tert-butylperoxyisopropyl)benzene, with dicetyl peroxydicarbonate and 1,3-bis(tert-butylperoxyisopropyl)benzene being preferred.

As the polypropylene MM, preferred are
(1) Modified polypropylene obtained by graft polymerizing maleic anhydride onto polypropylene having propylene monomer and optionally ethylene monomer as main structural units;
(2) Modified polypropylene obtained by copolymerizing an olefin mainly composed of a propylene monomer and optionally an ethylene monomer with a glycidyl methacrylate ester or maleic anhydride;
Examples include:

Furthermore, from the viewpoint of mechanical strength such as impact strength, fatigue properties, and rigidity of fiber-reinforced resin molded products, a preferred polypropylene MM is maleic anhydride-modified polypropylene containing 0.01 to 10 weight % of polymerized monomer units derived from unsaturated carboxylic acids and/or their derivatives. In particular, in the case of polypropylene MM obtained by random copolymerization or block copolymerization using unsaturated carboxylic acids and/or their derivatives, the content of polymerized monomer units derived from unsaturated carboxylic acids and/or their derivatives is preferably 3 to 10 weight %, and in the case of polypropylene MM obtained by graft polymerization, the content of polymerized monomer units derived from unsaturated carboxylic acids and/or their derivatives is preferably 0.01 to 10 weight %.

The content of the oxazoline-modified polypropylene (component 1) contained in the polypropylene composition of the present invention is not particularly limited, but is preferably in the range of 1 to 20% by mass, more preferably in the range of 3 to 20% by weight, and even more preferably in the range of 5 to 20% by weight, where the total mass of the polypropylene composition of the present invention is 100% by mass.
The content of polypropylene (component 2) that can be contained in the polypropylene composition of the present invention is not particularly limited, but is preferably in the range of 30 to 98% by mass, and more preferably in the range of 50 to 90% by mass, where the total mass of the polypropylene composition of the present invention is 100% by mass.
The content of the filler (component 3) that can be contained in the polypropylene composition of the present invention is not particularly limited, but is preferably in the range of 1 to 50% by mass, more preferably in the range of 3 to 40% by mass, and even more preferably in the range of 15 to 30% by mass, where the total mass of the polypropylene composition of the present invention is 100% by mass.
The content of the other modified polypropylene (component 4) that can be contained in the polypropylene composition of the present invention is not particularly limited.

In one embodiment, the polypropylene composition of the present invention contains (Component 1):
(Component 1) Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2):
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1×10 ⁻² to 100×10 ⁻² mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min.

In one embodiment, the polypropylene composition of the present invention contains (Component 1):
(Component 1) Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2): Content: 1 to 20% by mass:
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1×10 ⁻² to 100×10 ⁻² mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min.

In one embodiment, the polypropylene composition of the present invention contains the following (Component 1), (Component 2), and (Component 3):
(Component 1) Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2): Content: 1 to 20% by mass:
(1) The oxazoline-modified polypropylene has an oxazoline group.
(1-a) the content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1 × 10 ^-2 to 100 × 10 ^-2 mmol/g, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min;
(Component 2) Polypropylene: content of 30 to 98 mass %, and (Component 3) at least one filler selected from the group consisting of carbon fiber, glass fiber, and talc: content of 1 to 50 mass %.

In one embodiment, the polypropylene composition of the present invention contains (Component 1):
(Component 1) Oxazoline-modified polypropylene produced by a process comprising the following steps:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.

In one embodiment, the polypropylene composition of the present invention contains (Component 1):
(Component 1) Oxazoline-modified polypropylene produced by a method comprising the following steps: Content: 1 to 20% by mass:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.

In one embodiment, the polypropylene composition of the present invention contains the following (Component 1), (Component 2), and (Component 3):
(Component 1) Oxazoline-modified polypropylene produced by a method comprising the following steps: Content: 1 to 20% by mass:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding an oxazoline compound to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture.
(Component 2) Polypropylene: content of 30 to 98 mass %, and (Component 3) at least one filler selected from the group consisting of carbon fiber, glass fiber, and talc: content of 1 to 50 mass %.

Molded Article The polypropylene composition of the present invention is used to produce a molded article, for example, by the following method.
The method for producing a molded article may include a method for producing a molded article, which comprises the steps of melting the polypropylene composition and molding it to obtain a molded article.
Examples of molding methods include extrusion molding and injection molding. Extrusion molding can produce, for example, a sheet-shaped molded product, while injection molding can produce an injection-molded product.
Examples of injection molding methods include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high speed injection molding, injection compression molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert-outsert molding.

Applications The polypropylene composition and molded article of the present invention can be used, for example, as automotive components such as automotive interior and exterior parts, automotive parts, motorcycles and automotive parts, housing-related parts, medical equipment, robot parts, aircraft parts, home appliance parts, electric and electronic parts, machine mechanism parts, power tool parts, food containers, sporting goods, and building material-related parts.

The present invention will be explained in more detail below using examples and comparative examples, but the present invention is not limited thereto.

Calculation method for bond components on carbon fiber surfaces

Removal of sizing agent The set temperature of the Dionex accelerated solvent extraction apparatus ASE-200 was set to 80°C, and 0.2 g of carbon fiber was placed in an extraction cell container with a volume of 11 ml and installed in the accelerated solvent extraction apparatus ASE-200. After injecting 11 ml of tetrahydrofuran (Kanto Chemical, special grade, stabilizer-free) into the extraction cell container, the pressure inside the extraction cell container was increased to 1000 psi and maintained for 15 minutes. Nitrogen was used to expel approximately half of the tetrahydrofuran from the outlet of the extraction cell container, and tetrahydrofuran was again injected into the extraction cell container until 11 ml remained, after which the pressure inside the extraction cell container was increased to 1000 psi and maintained for 10 minutes. Furthermore, nitrogen was used to expel approximately half of the tetrahydrofuran from the outlet of the extraction cell container, and tetrahydrofuran was again injected into the extraction cell container until 11 ml remained, after which the pressure inside the extraction cell container was increased to 1000 psi and maintained for 10 minutes. Nitrogen was then injected into the extraction cell for 2 minutes to expel the tetrahydrofuran from the outlet of the extraction cell, and the carbon fibers were removed from the extraction cell and dried under vacuum at 40° C. for at least 15 hours.

X-ray photoelectron spectroscopy (XPS) analysis: The carbon fiber subjected to the above-described procedure was then placed in an X-ray photoelectron spectroscopy apparatus (AXIS ULTRA DLD manufactured by Shimadzu/KRATOS). Monochromated Al Kα (1486.6 eV) was used as the X-ray source and used as the excitation light. The output was set to a tube current of 10 mA and a tube voltage of 15 kV, and the photoelectron take-off angle, defined as the angle between the sample normal and the photoelectron take-off direction, was set to 0°. The background of the obtained carbon 1s spectrum was removed by the Shirley method.

The background-subtracted carbon 1s spectrum was subjected to waveform separation into peaks derived from C-C bond components, C-N bond components, C-O bond components, C=O bond components, and O-C=O bond components using a Gauss-Lorentz composite function with a 30% Lorentz function ratio, according to the method described in Composites: Part A 90 (2016) 653-661 (Bo Gao et al.).

The spectral areas of the C-C bond component, C-N bond component, C-O bond component, C=O bond component, and O-C=O bond component obtained by waveform separation were determined, and the percentage of the spectral area of the C-O bond component and the percentage of the total spectral area of the C=O bond component and the O-C=O bond component relative to the total amount of the C-C bond component, C-N bond component, C-O bond component, C=O bond component, and O-C=O bond component (100%) were calculated.

Example of oxazoline-modified polypropylene

Example M1: Oxazoline-modified polypropylene-1

M1-1) Maleic anhydride modified polypropylene-1
Maleic anhydride-modified polypropylene-1 was produced using Synthesis Example 2 described in WO2020/009090.

M1-2) Oxazoline-modified polypropylene-1
100 parts by weight of the maleic anhydride-modified polypropylene-1 synthesized above, 0.46 parts by weight of an oxazoline compound (manufactured by Mikuni Pharmaceutical Co., Ltd., product name CP Resin A 1,3-PBO), 0.2 parts by weight of antioxidant 1 (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GA80), and 0.2 parts by weight of antioxidant 2 (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GP) were mixed and melt-kneaded in a twin-screw kneader (manufactured by Technovel Co., Ltd., KZW12TW-60/75mg-NH, screw diameter 12 mm, L/D = 75, cylinder temperature 250 °C, rotation speed 300 rpm, discharge rate 2 kg/hr) while degassing through a vacuum vent to obtain oxazoline-modified polypropylene-1. The MFR (230 °C, 2.16 kg load) of the resulting oxazoline-modified polypropylene-1 was 152 g/10 min.

Examples M2 to M4: Oxazoline-modified polypropylene-2 to Oxazoline-modified polypropylene-4
Oxazoline-modified polypropylene-2 to oxazoline-modified polypropylene-4 of Examples M2 to M4 were produced in the same manner as for oxazoline-modified polypropylene-1, except that the materials shown in Table 1 were used.

Examples M5 to M7: Oxazoline-modified polypropylene-5 to Oxazoline-modified polypropylene-7
Oxazoline-modified polypropylene-5 to oxazoline-modified polypropylene-7 of Examples M5 to M7 were produced in the same manner as in the production of oxazoline-modified polypropylene-1, except that the materials shown in Table 2 were used.

As the maleic anhydride-modified polypropylene-2, the following maleic anhydride-modified polypropylene was used.
Maleic anhydride modified polypropylene-2: Bondyram 1001 manufactured by Polyram Plastic Industries
MFR (230℃, load 21.2N): 315g/10min

Comparative Example M8: Oxazoline-modified polypropylene-8
100 parts by mass of maleic anhydride-modified polypropylene-3, 2.35 parts by mass of an oxazoline compound (manufactured by Mikuni Pharmaceutical Co., Ltd., trade name CP Resin A 1,3-PBO), 0.2 parts by mass of antioxidant 1 (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GA80), and 0.2 parts by mass of antioxidant 2 (manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GP) were mixed and melt-kneaded in a twin-screw kneader (manufactured by Technovel Co., Ltd., KZW12TW-60/75mg-NH, screw diameter 12 mm, L/D = 75, cylinder temperature 200 ° C, rotation speed 300 rpm, discharge rate 1.5 kg/hr) while degassing through a vacuum vent to obtain oxazoline-modified polypropylene-8. The MFR (230 ° C, 2.16 kg load) of the obtained oxazoline-modified polypropylene-8 was 648 g/10 min.

As the maleic anhydride-modified polypropylene-3, the following maleic anhydride-modified polypropylene was used.
Maleic anhydride modified polypropylene-3: UMEX 1010 manufactured by Sanyo Chemical Industries, Ltd.

Relationship between normalized absorbance derived from oxazoline groups and oxazoline group content in oxazoline-containing polypropylene homopolymers. An oxazoline compound (manufactured by Mikuni Pharmaceutical Co., Ltd., product name CP Resin A 1,3-PBO) and polypropylene homopolymer 1 (manufactured by Sumitomo Chemical Co., Ltd., Noblen HR100EG) were melt-kneaded using a kneader (Labo Plastomill, manufactured by Toyo Seiki Seisakusho). Multiple oxazoline-containing polypropylene homopolymers were obtained by varying the blending ratio of the oxazoline compound to polypropylene homopolymer 1. The oxazoline group content in the oxazoline-containing polypropylene homopolymer was calculated from the oxazoline compound content in the resulting oxazoline-containing polypropylene homopolymer. Next, the resulting sample was preheated at 210°C for 5 minutes, and a pressure of 5 MPa was applied for 5 minutes, followed by press molding to produce a sample with a thickness of 300 μm. The transmission spectrum of the produced molded article was measured using a Fourier transform infrared spectrophotometer (FT/IR, JASCO Corporation 6200) at a wavenumber of 600 to 4000 cm ^-1 . The absorbance attributable to the oxazoline groups in the oxazoline-containing polypropylene homopolymer was normalized using the absorbance I _A at 1655 cm ^-1 attributable to the oxazoline groups in the obtained IR spectrum and the absorbance I _B at 841 cm ^-1 according to the following formula (1), and the normalized absorbance was designated as α _A. A calibration curve of α _A and the oxazoline group content in the oxazoline-containing polypropylene homopolymer was prepared using α _A and the oxazoline group content X mmol/g. From the prepared calibration curve, it was found that α _A and the oxazoline group content X mmol/g were related by the following formula (2).
α _A = I _A /I _B (1)
X=0.3849× _αA (2)

Calculation method for oxazoline group content per 1 g of oxazoline-modified polypropylene. The maleic anhydride-modified polypropylene used in synthesizing the oxazoline-modified polypropylene was preheated at 190°C for 5 minutes, and a 100 μm thick sample was press-molded at a pressure of 5 MPa for 5 minutes. 0.3 g was cut out from the press-molded product, and the cut-out sample was placed in 30 ml of ethanol. The sample was then left to stand at 30°C for 60 hours, filtered, air-dried, and then vacuum-dried at room temperature for at least 18 hours. The obtained sample was preheated at 210°C for 5 minutes, and a 5 MPa pressure was applied for 5 minutes to produce a sample with a thickness of 100 μm to 300 μm by press-molding. The transmission spectrum of the press-molded product was measured at wavenumbers of 600 to 4000 cm ^-1 using a Fourier transform infrared spectrophotometer (FT/IR, JASCO Corporation 6200). The absorbance I _C at a wave number of 1655 cm ⁻¹ of the obtained spectrum was normalized using the absorbance I _D at a wave number of 841 cm ⁻¹ according to the following formula (3), and the normalized absorbance was defined as α _B.
A press-molded body of oxazoline-modified polypropylene was also prepared using the same procedure, and its transmission spectrum was measured using FT/IR. The absorbance I _E at a wavenumber of 1655 cm ^-1 of the obtained spectrum and the absorbance I _F at a wavenumber of 841 cm ^-1 were used to normalize the absorbance derived from oxazoline groups in the oxazolinic acid-modified polypropylene according to the following equation (4), and the normalized absorbance was designated as _αC . The absorbance _αD derived from oxazoline groups in the oxazoline-modified polypropylene was calculated according to the following equation (5) using _αB and _αC . The content of oxazoline groups Y mmol/g per 1 g of oxazoline-modified polypropylene was calculated from _αD and equation (2).
α _B =I _C /I _D (3)
α _C = I _E /I _F (4)
α _D = α _C − α _B (5)
Y=0.3849×α _D (mmol/g) (6)

Materials Used The following materials were used in the examples and comparative examples.

1. Oxazoline-modified polypropylene (component 1)
Oxazoline modified polypropylene 1
Oxazoline-modified polypropylene-1 of the above example
MFR (230°C, load 21.2N): 152g/10min Oxazoline group content: 2.0 x ^10-2 mmol/g

Oxazoline modified polypropylene 2
Oxazoline-modified polypropylene-2 of the above example
MFR (230°C, load 21.2N): 41 g/10 min Oxazoline group content: 11.2 x ^10-2 mmol/g

Oxazoline modified polypropylene 3
Oxazoline-modified polypropylene-3 of the above example
MFR (230°C, load 21.2N): 6.9g/10min Oxazoline group content: 19.0 x ^10-2 mmol/g

Oxazoline modified polypropylene 4
Oxazoline-modified polypropylene-4 of the above example
MFR (230°C, load 21.2N): 2.3 g/10 min Oxazoline group content: 20.7 x ^10-2 mmol/g

Oxazoline modified polypropylene 5
Oxazoline-modified polypropylene-5 of the above example
MFR (230°C, load 21.2N): 275g/10min Oxazoline group content: 0.2 x ^10-2 mmol/g

Oxazoline modified polypropylene 6
Oxazoline-modified polypropylene-6 of the above example
MFR (230°C, load 21.2N): 238g/10min Oxazoline group content: 3.1 x ^10-2 mmol/g

Oxazoline modified polypropylene 7
Oxazoline-modified polypropylene-7 of the above example
MFR (230°C, load 21.2N): 162g/10min Oxazoline group content: 6.4 x ^10-2 mmol/g

Modified polypropylene of Comparative Example C1 Maleic anhydride modified polypropylene-1 used in synthesizing Example M1
MFR (230°C, load 21.2N): 199 g/10 min Oxazoline group content: 0.0 x ^10-2 mmol/g

Modified polypropylenes of comparative examples C2 and C3 Oxazoline modified polypropylene-8
MFR (230°C, load 21.2N): 648g/10min Oxazoline group content: 14.9 x ^10-2 mmol/g

2. Polypropylene (component 2)
Polypropylene homopolymer 1 (Noblen HR100EG manufactured by Sumitomo Chemical Co., Ltd.)
MFR (230°C, load 21.2N): 23g/10min Melting point: 164°C

3. Filler (ingredient 3)
Carbon fiber 1 (CFRI T8S103C manufactured by Carbon Fiber Recycle Industry Co., Ltd.)
C—O bonds: 5.2%, total of C═O bonds and O—C═O bonds: 5.8%

Glass fiber 1 (Owes Corning CS 249A-10C)

4. Other Materials Antioxidant 3: Irganox 1010 manufactured by BASF Japan Ltd.
Antioxidant 4: Irgafos 168 manufactured by BASF Japan Ltd.
Neutralizer: Calcium stearate manufactured by Sun Ace Co., Ltd.

Melting and injection molding production

Example C1
70% by mass of polypropylene homopolymer 1, 10% by mass of oxazoline-modified polypropylene 1, 20% by mass of carbon fiber 1, and 0.2 parts by mass of antioxidant 3 and 0.2 parts by mass of antioxidant 4 were mixed to obtain a mixture, relative to a total of 100 parts by mass of polypropylene homopolymer 1, oxazoline-modified polypropylene 1, and carbon fiber 1. The mixture was melt-kneaded using a 40 mm single-screw extruder (VS40-28 vented extruder, manufactured by Tanabe Plastics Co., Ltd.) at a cylinder temperature of 220 ° C. and a screw rotation speed of 100 rpm, and pelletized to obtain a polypropylene composition. The obtained polypropylene composition was injection-molded using an injection molding machine (M-70CSJ manufactured by Meiki Seisakusho Co., Ltd.) under conditions of a cylinder temperature of 220 ° C., a mold temperature of 50 ° C., and an injection speed of 20 mm / sec, to obtain an injection-molded ISO test piece.

Examples C2 to C7 and Comparative Examples C1 to C2
The polypropylene compositions of Examples C2 to C7 and Comparative Examples C1 and C2 were produced in the same manner as in Example C1, except that the materials shown in Table 4 were used. For convenience, the maleic anhydride-modified polypropylene used to produce the polypropylene of Comparative Example 1 is listed in the box for "Component 1."

Example C8
58.5% by mass of polypropylene homopolymer 1, 1.5% by mass of oxazoline-modified polypropylene 2, 40% by mass of glass fiber 1, and 0.2 parts by mass of antioxidant 3, 0.2 parts by mass of antioxidant 4, and 0.05 parts by mass of neutralizer were mixed to obtain a mixture. The mixture was melt-kneaded using a 32 mm twin-screw extruder (twin-screw extruder ZSK32Mc18, manufactured by Coperion) at a cylinder temperature of 230 ° C. and a screw rotation speed of 400 rpm, and pelletized to obtain a polypropylene composition. The obtained polypropylene composition was injection-molded using an injection molding machine (M-70CSJ manufactured by Meiki Seisakusho Co., Ltd.) under conditions of a cylinder temperature of 220 ° C., a mold temperature of 50 ° C., and an injection speed of 20 mm / sec, to obtain an injection-molded ISO test piece.

Comparative Example C3
A polypropylene composition of Comparative Example C3 was produced in the same manner as in Example C8, except that the materials shown in Table 5 were used.

Evaluation of physical properties 1. Melt mass-flow rate (MFR) (unit: g/10 min)
The melt mass-flow rate was measured according to the method specified in JIS K 7210 at a measurement temperature of 230° C. and a load of 2.16 kg.

2. Density (unit: g/cm ³ )
The molded article molded by the molding method described in the above "Melt kneading and production of injection molded article" was cut into a size of 80 mm × 10 mm × 4 mm, and used as a test piece to measure the density according to the underwater displacement method, which is Method A specified in JIS K7112.

3. Tensile breaking strength (unit: MPa)
Using test pieces having a thickness of 4 mm molded by the molding method described in the above "Melt kneading and production of injection molded articles," the tensile breaking strength (US) was measured at a pulling rate of 50 mm/min according to the method specified in ISO 527-2.

4. Bending strength (unit: MPa)
Using test pieces having a thickness of 4 mm molded by the molding method described in the above "Melt kneading and production of injection molded articles," the flexural strength (FS) was measured at a loading rate of 2.0 mm/min according to the method specified in ISO 178.

5. Notched Charpy impact strength (unit: kJ/m ² )
The molded article molded by the molding method described above in "Melt kneading and production of injection molded articles" was cut into a size of 80 mm x 10 mm x 4 mm, notched, and used as a test piece to measure the notched Charpy impact strength by edgewise impact according to the method specified in ISO 179-1. The notch shape was shape A described in ISO 179-1.

Claims (6)

Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2):
(1) Oxazoline-modified polypropylene is polypropylene modified with maleic acid or maleic anhydride and a compound of formula 1,

R1 represents a divalent organic group ^;
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1 × 10 ^-2 to 100 × 10 ^-2 mmol/g , and the oxazoline group means a carbonylaminoethyl group in which the oxazoline ring is opened, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min. An oxazoline-modified polypropylene having a melt mass-flow rate of 0.01 to 300 g/10 min and an oxazoline group content of 0.1×10 ⁻² to 100×10 ⁻² mmol/g per 1 g of the oxazoline-modified polypropylene , the oxazoline group meaning a carbonylaminoethyl group in which the oxazoline ring is opened, the oxazoline-modified polypropylene being produced by a method comprising the following steps:
a step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and a step of adding the oxazoline compound of Formula 1 to the obtained melt-kneaded mixture of polypropylene, an organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture .

R1 represents a divalent organic group ^. A method for producing an oxazoline-modified polypropylene having a melt mass-flow rate of 0.01 to 300 g/10 min and an oxazoline group content of 0.1×10 ⁻² to 100×10 ⁻² mmol/g per 1 g of the oxazoline-modified polypropylene, the method comprising the steps of :
A step of melt-kneading polypropylene, an organic peroxide, and maleic acid or maleic anhydride;
a step of adding the oxazoline compound of formula 1 to the melt-kneaded mixture of the obtained polypropylene, organic peroxide, and maleic acid or maleic anhydride, and melt-kneading the mixture ;

R1 represents a divalent organic group ^. A polypropylene composition comprising (component 1):
(Component 1) Oxazoline-modified polypropylene satisfying the following requirements (1), (1-a), and (2):
(1) Oxazoline-modified polypropylene is polypropylene modified with maleic acid or maleic anhydride and a compound of formula 1,

R1 represents a divalent organic group ^;
(1-a) The content of oxazoline groups in 1 g of the oxazoline-modified polypropylene is 0.1 × 10 ^-2 to 100 × 10 ^-2 mmol/g , and the oxazoline group means a carbonylaminoethyl group in which the oxazoline ring is opened, and (2) the melt mass-flow rate of the oxazoline-modified polypropylene is 0.01 to 300 g/10 min. The polypropylene composition according to claim 4 , comprising (component 1): in a content of 1 to 20 mass%, and the following (component 2) and (component 3):
(Component 2) Polypropylene: content of 30 to 98 mass %, and (Component 3) at least one filler selected from the group consisting of carbon fiber, glass fiber, and talc: content of 1 to 50 mass %. The polypropylene composition according to claim 4 or 5 , which contains (component 3) carbon fiber as a filler.