JP2024016462A - Polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition having a crystallization temperature higher than that of a polyamide resin.

SOLUTION: A polyamide resin composition contains a polyamide resin, an organic crystal nucleating agent and an auxiliary composed of a fatty acid metal salt, wherein the crystal nucleating agent is an organic phosphorous compound having less than 15 carbon atoms.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a polyamide resin composition.

For example, many resin molded products are used in vehicles. Such resin molded products are generally formed by injection molding. In injection molding, molten resin is supplied to a mold cavity and then cooled to perform molding. For example, Patent Document 1 discloses a polyamide resin composition used for such injection molding.

Japanese Patent Application Publication No. 5-194841

The chemical structure of polyamide resin includes amide groups (-CONH), and when the molecular chains come close to each other, interactions (hydrogen bonds) between the amide groups occur. As a result, molecular alignment occurs and a crystal structure is generated. A crystal nucleating agent may be added to such crystalline thermoplastic resins such as polyamide resins in order to promote crystallization. As organic crystal nucleating agents, crystal nucleating agents having a carbon number of 15 or more and having a cyclic structure or an ester structure are being considered. However, even when such a crystal nucleating agent is added to a polyamide resin, the crystallization temperature cannot be increased and the solidification of the resin cannot be accelerated.

The present invention was made in view of the above-mentioned problems, and an object of the present invention is to provide a polyamide resin composition having a higher crystallization temperature than polyamide resins.

The present invention employs the following configuration as a means for solving the above problems.

One embodiment of the present invention includes a polyamide resin, an organic crystal nucleating agent, and an auxiliary agent consisting of a fatty acid metal salt, and the crystal nucleating agent is an organic phosphorus compound having less than 15 carbon atoms. adopt.

According to the present invention, it is possible to provide a polyamide resin composition having a higher crystallization temperature than a polyamide resin.

FIG. 1 is a schematic diagram of a resin intake manifold formed from a polyamide resin composition in an embodiment of the present invention.

Hereinafter, one embodiment of the polyamide resin composition according to the present invention will be described with reference to the drawings.

The polyamide resin composition of this embodiment includes a polyamide resin, an organic crystal nucleating agent, and an auxiliary agent consisting of a fatty acid metal salt. In addition, the polyamide resin composition may also contain a polyamide oligomer.

[polyamide]
As the polyamide resin (polyamide), for example, ring-opening polymers of cyclic lactams, polycondensates of aminocarboxylic acids, and polycondensates of dibasic acids and diamines are used. Specifically, aliphatic polyamides such as nylon 6, nylon 4/6, nylon 6/6, nylon 6/10, nylon 6/12, nylon 11, and nylon 12, poly(methaxylene adipamide), poly( Aliphatic-aromatic polyamides such as poly(hexamethylene terephthalamide), poly(hexamethylene isophthalamide), poly(tetramethylene isophthalamide), and copolymers and mixtures thereof can be used. In particular, nylon 6 can be used as a polyamide suitable for the polyamide resin composition of this embodiment.

[Crystal nucleating agent]
As the organic crystal nucleating agent, an organic phosphorus compound having less than 15 carbon atoms is used. Polyamide has amide groups in its molecular structure, and when the molecular chains come close to each other, interactions (hydrogen bonds) between the amide groups occur. As a result, molecular alignment is promoted and a crystal structure is obtained. Therefore, unless the crystal nucleating agent that acts as a relay between molecular chains can enter between the molecular chains, the effect of increasing the crystallization temperature and promoting crystallization cannot be obtained.

An organic phosphorus compound having less than 15 carbon atoms can enter between the molecular chains of polyamide. Furthermore, in the case of an organic phosphorus compound having an oxo acid structure having a hydroxy group and an oxo group, or an organic phosphorus compound having an ester structure having a hydroxy group and an oxo group, the combination of a hydroxy group and an oxo group and an amide group. Interactions promote molecular alignment. As a result, the crystallization temperature of the polyamide resin composition can be increased compared to when a crystal nucleating agent having carbon number of 15 or more is used or when no crystal nucleating agent is used. As the crystallization temperature of the polyamide resin composition increases, crystallization starts at a high temperature while the molten polyamide resin composition is being cooled. That is, in injection molding, the solidification of the polyamide resin composition can be accelerated.

An example of an organic phosphoric acid compound having an oxo acid structure having a hydroxy group and an oxo group is phenylphosphonic acid represented by the following formula (1). When such phenylphosphonic acid is used as a crystal nucleating agent, the average particle size of the phenylphosphonic acid is, for example, 40 μm, although it is not particularly limited.

Examples of organic phosphorus compounds having an ester structure having a hydroxy group and an oxo group include phosphoric acid ester compounds represented by the following formula (2). R in the following formula (2) represents a hydroxy group, an alkyl group, or a cyclic compound, and is a group having 10 or less carbon atoms. R' in the following formula (2) represents hydrogen or an alkyl group, and is a group having 10 or less carbon atoms. R'' in the following formula (2) represents hydrogen or an alkyl group, and is a group having 10 or less carbon atoms. Note that R' and R'' may be the same or different. The organic phosphorus compound used as a crystal nucleating agent has a total carbon number of less than 15.

In the polyamide resin composition of the present embodiment, the content of such a crystal nucleating agent is preferably 0.005 to 5 parts by weight based on 100 parts by weight of the polyamide resin. Furthermore, in the polyamide resin composition of the present embodiment, the content of the crystal nucleating agent is particularly preferably 0.3 parts by weight per 100 parts by weight of the polyamide resin.

[Fatty acid metal salt]
As the fatty acid metal salt, for example, one obtained from a fatty acid having 10 or more and less than 25 carbon atoms and a metal of Groups I to III of the periodic table can be used. In particular, fatty acids having 12 or more and less than 22 carbon atoms are preferred.

As the fatty acid for obtaining the fatty acid metal salt, stearic acid, valmitic acid, oleic acid, aragic acid, behenic acid, etc. can be used. In particular, it is preferable to use stearic acid as the fatty acid for obtaining the fatty acid metal salt.

Further, as the metal for obtaining the fatty acid metal salt, magnesium, zinc, calcium, lithium, aluminum, barium, etc. can be used. In particular, magnesium is preferred as the metal for obtaining the fatty acid metal salt.

As the fatty acid metal salt, magnesium stearate, zinc stearate, calcium stearate, lithium stearate, aluminum stearate, barium stearate, etc. can be used. In particular, magnesium stearate is preferred as the fatty acid metal salt. Although not particularly limited, the average particle size of magnesium stearate is, for example, 1 μm to 100 μm.

In the polyamide resin composition of the present embodiment, the content of the fatty acid metal salt is preferably 0.005 to 5 parts by weight based on 100 parts by weight of the polyamide resin. Furthermore, in the polyamide resin composition of the present embodiment, the content of the fatty acid metal salt is particularly preferably 0.1 parts by weight.

For example, in a polyamide resin composition, the content ratio of the crystal nucleating agent is 0.3 parts by weight per 100 parts by weight of the polyamide resin, and the content ratio of the fatty acid metal salt is 0.1 parts by weight per 100 parts by weight of the polyamide resin. If it is expressed in parts by weight, the crystallization temperature of the polyamide resin composition can be made higher than when a crystal nucleating agent having a carbon number of 15 or more is used or when no crystal nucleating agent is used.

The method for producing the polyamide resin composition of this embodiment is not particularly limited. For example, the polyamide resin composition of this embodiment can be prepared by adding a crystal nucleating agent and a fatty acid metal salt during polyamide polymerization, by dry blending after polymerization, by attaching a crystal nucleating agent and a fatty acid metal salt to the pellet surface, and by melt-kneading. It may be produced by any method such as a method in which concentrate pellets of a crystal nucleating agent or a fatty acid metal salt are prepared by melt-kneading and the concentrate pellets are dry blended. When a melt-kneading method is employed, pellets of the mixture can be obtained by melt-kneading using, for example, a Banbury mixer, a mixing roll, a single-screw or twin-screw extruder, or the like.

Other components may be added to the polyamide resin composition of this embodiment to the extent that moldability and physical properties are not impaired. For example, the polyamide resin composition of the present embodiment includes polyamide components other than the above-mentioned polyamide, a copper compound, a heat stabilizer, a weathering agent, an inorganic filler, a reinforcing agent, an antioxidant, an impact modifier, a pigment, and a lubricant. , flame retardants, etc. may be added.

The polyamide resin composition of this embodiment has a high crystallization temperature and can accelerate the solidification of the polyamide resin composition during injection molding, so it can be suitably used as a forming material for injection molded products. An example of an injection molded product using the polyamide resin composition of this embodiment is a resin intake manifold 1 as shown in FIG. In other words, the resin intake manifold 1 is formed by melting the polyamide resin composition of this embodiment, injecting it into the cavity of a mold, and cooling and solidifying the polyamide resin composition of this embodiment inside the mold. Can be done.

In addition, injection molded products that can be formed using the polyamide resin composition of this embodiment include throttle body gear parts, brake peripheral parts such as brake pistons, injector parts, EGR valve parts, damper parts, etc. suspension parts, power steering parts, and fuel pump module parts.

Injection molded products that can be formed using the polyamide resin composition of this embodiment include switches, micro slide switches, DIP switches, switch housings, lamp sockets, cable ties, connectors, connector housings, and connector housings. Shells, IC sockets, coil bobbins, bobbin covers, relays, relay boxes, condenser cases, motor internal parts, small motor cases, gears, cams, dancing pulleys, spacers, insulators, fasteners, buckles, wire clips, bicycle wheels, Casters, terminal blocks, power tool housings, starter insulation parts, canisters, fuse boxes, air cleaner cases, air conditioner fans, terminal housings, wheel covers, bearing retainers, cylinder head covers, water pipe impellers, clutch release bearing hubs, speakers Electrical or electronic-related parts such as diaphragms, heat-resistant containers, microwave oven parts, rice cooker parts, printer ribbon guides, etc., automobile and vehicle-related parts, household and office electrical product parts, computer-related parts, and facsimiles. This also includes parts related to machines, copying machines, and machinery.

The polyamide resin composition of this embodiment as described above includes a polyamide resin, an organic crystal nucleating agent, and an auxiliary agent consisting of a fatty acid metal salt. Further, the crystal nucleating agent is an organic phosphorus compound having less than 15 carbon atoms. The polyamide resin composition of this embodiment has a crystallization temperature higher than that of the polyamide resin.

Furthermore, in the polyamide resin composition of the present embodiment, an organic phosphorus compound having an oxo acid structure having a hydroxy group and an oxo group can be used as the crystal nucleating agent. Furthermore, in the polyamide resin composition of the present embodiment, an organic phosphorus compound having an ester structure having at least an oxo group can be used as the crystal nucleating agent.

According to the polyamide resin composition of this embodiment, the interaction between the hydroxy group or oxo group and the amide group can promote molecular alignment and increase the crystallization temperature.

Moreover, in the polyamide resin composition of this embodiment, it is preferable that the crystal nucleating agent is 0.3 part by weight and the auxiliary agent is 0.1 part by weight with respect to 100 parts by weight of the polyamide resin. According to the polyamide resin composition of this embodiment, the crystallization temperature can be significantly increased.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above embodiments. The embodiments described above are merely examples, and various changes can be made based on design requirements and the like without departing from the spirit of the present invention.

Next, an example of the present invention will be described. The conditions in the example are examples of conditions adopted to confirm the feasibility and effects of the present invention, and the present invention is based on this example of conditions. It is not limited. The present invention can adopt various conditions as long as the purpose of the present invention is achieved without departing from the gist of the present invention.

In this example, a single-screw extruder was used to continuously extrude the materials for forming a polyamide resin composition while melt-mixing, cooled by a cooling device, pulled out by a drawing device, and then cut into pellets by a cutting device. Resin pellets were formed by cutting into pieces.

Further, in this example, the crystallization temperature of the resin pellet was measured using DSC-60 (manufactured by Shimadzu Corporation). The measurement temperature range is room temperature to 300°C. The temperature increasing condition was 10° C./min, and the high temperature condition was also 10° C./min. Furthermore, measurements were performed in a nitrogen atmosphere.

(Example 1)
In Example 1, nylon 6 containing 30% glass fiber was used as the polyamide, phenylphosphonic acid represented by the above formula (1) was used as the crystal nucleating agent, and magnesium stearate was used as the fatty acid metal salt. Further, the content ratio of the crystal nucleating agent was 0.3 parts by weight per 100 parts by weight of the polyamide resin, and the content ratio of the fatty acid metal salt was 0.1 parts by weight per 100 parts by weight of the polyamide resin.

(Example 2)
In Example 2, nylon 6 containing 30% glass fiber was used as the polyamide, a phosphate ester compound represented by the above formula (2) was used as the crystal nucleating agent, and magnesium stearate was used as the fatty acid metal salt. there was. Further, the content ratio of the crystal nucleating agent was 0.3 parts by weight per 100 parts by weight of the polyamide resin, and the content ratio of the fatty acid metal salt was 0.1 parts by weight per 100 parts by weight of the polyamide resin.

(Comparative example 1)
In Comparative Example 1, nylon 6 containing 30% glass fiber was used as the polyamide, and no crystal nucleating agent or fatty acid metal salt was added.

(Comparative example 2)
In Comparative Example 2, nylon 6 containing 30% glass fiber was used as the polyamide, and a metal phosphate (an organic crystal nucleating agent having 15 or more carbon atoms) represented by the following formula (3) was used as the crystal nucleus. Magnesium stearate was used as a fatty acid metal salt. Further, the content ratio of the crystal nucleating agent was 0.3 parts by weight per 100 parts by weight of the polyamide resin, and the content ratio of the fatty acid metal salt was 0.1 parts by weight per 100 parts by weight of the polyamide resin.

(Comparative example 3)
In Comparative Example 3, nylon 6 containing 30% glass fiber was used as the polyamide, and a terpene phenol resin (an organic crystal nucleating agent having 15 or more carbon atoms) represented by the following formula (4) was used as the crystal nucleating agent. Magnesium stearate was used as the fatty acid metal salt. Further, the content ratio of the crystal nucleating agent was 0.3 parts by weight per 100 parts by weight of the polyamide resin, and the content ratio of the fatty acid metal salt was 0.1 parts by weight per 100 parts by weight of the polyamide resin.

The crystallization temperature in Example 1 was 185°C. The crystallization temperature of Example 2 was 178°C. The crystallization temperature of Comparative Example 1 was 175°C. The crystallization temperature of Comparative Example 2 was 173°C. The crystallization temperature of Comparative Example 3 was 175°C.

As can be seen from the crystallization temperature of Comparative Example 2 and Comparative Example 3, when an organic crystal nucleating agent having 15 or more carbon atoms is used, the crystal nucleating agent and fatty acid metal salt are not added. The results showed that the crystallization temperature decreased or did not change compared to Comparative Example 1, which did not have any crystallization temperature.

On the other hand, as can be seen from the crystallization temperature in Example 1 and the crystallization temperature in Example 2, when an organic crystal nucleating agent having less than 15 carbon atoms is used, the crystal nucleating agent and fatty acid metal salt are The result was an increase in the crystallization temperature compared to Comparative Example 1 in which no addition was made.

Note that the above embodiment can also be described, for example, as in the following additional notes.

(Additional note 1)
polyamide resin,
an organic crystal nucleating agent;
and an auxiliary agent consisting of a fatty acid metal salt,
A polyamide resin composition, wherein the crystal nucleating agent is an organic phosphorus compound having less than 15 carbon atoms.

(Additional note 2)
The polyamide resin composition according to appendix 1, wherein the crystal nucleating agent is the organic phosphorus compound having an oxoacid structure having a hydroxy group and an oxo group.

(Additional note 3)
The polyamide resin composition according to appendix 1, wherein the crystal nucleating agent is the organic phosphorus compound having an ester structure having at least an oxo group.

(Additional note 4)
According to any one of Supplementary Notes 1 to 3, wherein the crystal nucleating agent is 0.3 parts by weight and the auxiliary agent is 0.1 parts by weight with respect to 100 parts by weight of the polyamide resin. The polyamide resin composition described.

1...Resin intake manifold

Claims (4)

polyamide resin,
an organic crystal nucleating agent;
and an auxiliary agent consisting of a fatty acid metal salt,
A polyamide resin composition, wherein the crystal nucleating agent is an organic phosphorus compound having less than 15 carbon atoms. 2. The polyamide resin composition according to claim 1, wherein the crystal nucleating agent is the organic phosphorus compound having an oxo acid structure having a hydroxy group and an oxo group. 2. The polyamide resin composition according to claim 1, wherein the crystal nucleating agent is the organic phosphorus compound having an ester structure having at least an oxo group. Any one of claims 1 to 3, wherein the crystal nucleating agent is 0.3 parts by weight and the auxiliary agent is 0.1 parts by weight relative to 100 parts by weight of the polyamide resin. The polyamide resin composition described in .

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