JP7141017B2 - Polyamide composition - Google Patents

Description

The present invention relates to polyamide compositions and the like. More particularly, it relates to a polyamide composition containing a semi-aromatic polyamide having dicarboxylic acid units mainly composed of naphthalenedicarboxylic acid units and diamine units mainly composed of aliphatic diamine units and a halogen-free flame retardant.

Semi-aromatic polyamides using aromatic dicarboxylic acids such as terephthalic acid and aliphatic diamines, and crystalline polyamides such as nylon 6 and nylon 66 are used for clothing because of their excellent properties and ease of melt molding. It is widely used as a fiber for industrial materials, general-purpose engineering plastics, etc. On the other hand, problems such as insufficient heat resistance and poor dimensional stability due to water absorption have been pointed out for these crystalline polyamides. In recent years, in particular, resinification of engine room parts has been actively studied for the purpose of improving fuel efficiency of automobiles. There is a desire for polyamides with

As a polyamide having excellent heat resistance, for example, Patent Document 1 discloses a semi-aromatic polyamide obtained from 2,6-naphthalenedicarboxylic acid and a linear aliphatic diamine having 9 to 13 carbon atoms. Patent Document 1 describes that the semi-aromatic polyamide is excellent in chemical resistance, mechanical properties, etc. in addition to heat resistance. On the other hand, Patent Document 1 describes that the use of an aliphatic diamine having a side chain is not preferable because the crystallinity of the obtained polyamide is lowered.

In Patent Document 2, 60 to 100 mol% of dicarboxylic acid units are composed of 2,6-naphthalenedicarboxylic acid units, and 60 to 100 mol% of diamine units are composed of 1,9-nonanediamine units and 2-methyl-1,8 -octanediamine units and having a molar ratio of 1,9-nonanediamine units to 2-methyl-1,8-octanediamine units of from 60:40 to 99:1. Patent Document 2 describes that the polyamide is excellent in mechanical properties, thermal decomposition resistance, low water absorption, chemical resistance, etc., in addition to heat resistance.
Furthermore, resin compositions containing semi-aromatic polyamides and uses of semi-aromatic polyamides have also been disclosed (for example, Patent Documents 3 and 4).

JP-A-50-67393 JP-A-9-12715 WO2012/098840 WO2005/102681

As described above, conventional polyamides such as Patent Documents 1 and 2 have physical properties such as heat resistance, mechanical properties, low water absorption, and chemical resistance, but further improvements in these physical properties are required.
Patent Document 2 describes the combined use of 1,9-nonanediamine and 2-methyl-1,8-octanediamine as aliphatic diamines. No mention is made of polyamides in the high proportion region.

Accordingly, an object of the present invention is to provide a polyamide composition which is excellent in various physical properties, excellent in flame retardancy, and has a low environmental impact, and a molded article made of the composition.

As a result of intensive studies by the present inventors, a specific polyamide having a dicarboxylic acid unit mainly composed of naphthalene dicarboxylic acid units and a diamine unit mainly composed of branched aliphatic diamine units and a polyamide composition containing a halogen-free flame retardant The present inventors have found that a product can solve the above problems, and have completed the present invention through further studies based on the findings.
That is, the present invention is as follows.

[1] containing a polyamide (A) having a dicarboxylic acid unit and a diamine unit and a halogen-free flame retardant (B),
More than 40 mol% and 100 mol% or less of the dicarboxylic acid units are naphthalene dicarboxylic acid units,
60 mol % or more and 100 mol % or less of the diamine units are branched aliphatic diamine units and linear aliphatic diamine units as optional structural units, and the branched aliphatic diamine units and the linear aliphatic diamine A polyamide composition in which the proportion of said branched aliphatic diamine unit is 60 mol % or more with respect to 100 mol % in total with the unit.
[2] A molded article made of the polyamide composition.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyamide composition which is excellent in various physical properties, excellent in flame retardancy, and has a low environmental load, and a molded article made of the composition.

2-methyl- 1 is a graph plotting the melting point (° C.) of a polyamide against the content ratio (mol %) of 1,8-octanediamine units.

The present invention will be described in detail below. In this specification, any definition that is considered preferable can be adopted arbitrarily, and it can be said that a combination of preferable items is more preferable. In this specification, the description "XX to YY" means "XX or more and YY or less".

<Polyamide composition>
The polyamide composition of the present invention contains a polyamide (A) having dicarboxylic acid units and diamine units and a halogen-free flame retardant (B).
As used herein, the term "unit" (here, "to" indicates a monomer) means "a structural unit derived from". For example, the term "dicarboxylic acid unit" means "derived from a A "structural unit" means a "structural unit derived from a diamine".

[Polyamide (A)]
Polyamide (A) contained in the polyamide composition of the present invention has dicarboxylic acid units and diamine units. More than 40 mol % and 100 mol % or less of the dicarboxylic acid units are naphthalenedicarboxylic acid units. In addition, 60 mol % or more and 100 mol % or less of the diamine units are branched aliphatic diamine units and linear aliphatic diamine units as optional structural units, and the branched aliphatic diamine units and the linear aliphatic The proportion of the branched aliphatic diamine unit is 60 mol % or more with respect to the total 100 mol % with the group diamine unit.

As described above, the polyamide (A) has dicarboxylic acid units mainly composed of naphthalenedicarboxylic acid units and diamine units mainly composed of branched aliphatic diamine units, thereby improving various properties such as chemical resistance. It has excellent physical properties, and the polyamide composition of the present invention containing the polyamide (A) and a halogen-free flame retardant also maintains the above-mentioned excellent properties and has excellent flame retardancy. Moreover, the polyamide composition has a small environmental load. Furthermore, various molded articles obtained from the polyamide composition can retain the excellent properties of the polyamide composition.

Physical properties such as high-temperature strength, mechanical properties, heat resistance, low water absorption, and chemical resistance that polyamides generally possess tend to improve as the crystallinity of the polyamide increases. Further, among polyamides having similar primary structures, the higher the crystallinity of the polyamide, the higher the melting point of the polyamide. Here, regarding the melting point of the polyamide, for example, a polyamide in which the diamine unit is a 1,9-nonanediamine unit and/or a 2-methyl-1,8-octanediamine unit and the dicarboxylic acid unit is a terephthalic acid unit is taken as an example. and the melting point of the polyamide (vertical axis) and the composition of diamine units (content ratio of 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units) (horizontal axis). is the minimum part. The melting points at both ends on the horizontal axis of the graph, that is, the melting point A1 when the linear 1,9-nonanediamine unit is 100 mol% and the branched 2-methyl-1,8-octanediamine unit is 100 mol. %, the melting point A1 is usually higher than the melting point B1 depending on the molecular structure of the diamine unit.
On the other hand, in the case of a polyamide in which the diamine unit is a 1,9-nonanediamine unit and/or a 2-methyl-1,8-octanediamine unit and the dicarboxylic acid unit is a 2,6-naphthalenedicarboxylic acid unit, the above While the minimum part is shown in a graph having the same vertical axis and horizontal axis as in, the melting point A2 when the 1,9-nonanediamine unit of the linear structure is 100 mol%, and the branched structure 2-methyl-1 When comparing the melting point B2 with 100 mol % of the ,8-octanediamine unit, it was surprisingly found that the melting point B2 is higher than the melting point A2.

Specifically, for a polyamide in which the dicarboxylic acid unit is a 2,6-naphthalene dicarboxylic acid unit and the diamine unit is a 1,9-nonanediamine unit and/or a 2-methyl-1,8-octanediamine unit, FIG. 1 shows a graph in which the melting point (° C.) of the polyamide is plotted against the 2-methyl-1,8-octanediamine unit content (mol %).
According to FIG. 1, 2-methyl-1,8 - It can be seen that the melting point of the polyamide decreases as the octanediamine unit content increases. On the other hand, when the content of 2-methyl-1,8-octanediamine units exceeds 50 mol %, it can be seen that the melting point of the polyamide increases significantly as the content increases. Comparing the melting points near both ends on the horizontal axis in FIG. It can be seen that the melting point is higher than the melting point when the content of 1,9-nonanediamine units in the structure is 100 mol %. Also for portions other than the vicinity of both ends on the horizontal axis, when the melting point of the region on the left and right of the border around the content of 50 mol% of the 2-methyl-1,8-octanediamine unit is compared, 2-methyl It can be seen that the melting point tends to be higher in the region on the right where the content of -1,8-octanediamine units is higher than in the region on the left where the content of 1,9-nonanediamine units is higher.

As described above, it was found that polyamides having diamine units mainly composed of 1,9-nonanediamine units and/or 2-methyl-1,8-octanediamine units exhibit different physical properties depending on the combined dicarboxylic acid units. . As a result of further studies by the present inventors, when the content of branched aliphatic diamine units is higher than that of linear aliphatic diamine units, by adopting naphthalene dicarboxylic acid units as dicarboxylic acid units, resistance Various physical properties such as chemical resistance and high-temperature heat resistance are further improved, and it has been found that flame retardancy is further improved by containing a halogen-free flame retardant, which will be described later. Although the reason for this is not necessarily clear, it is presumed to be due to the mutual relationship between the appropriate ratio of the branched structure in the diamine unit and the presence of the naphthalene skeleton in the dicarboxylic unit in the polyamide.

(Dicarboxylic acid unit)
More than 40 mol % and 100 mol % or less of dicarboxylic acid units are naphthalenedicarboxylic acid units. When the content of the naphthalene dicarboxylic acid unit in the dicarboxylic acid unit is 40 mol% or less, improvement of various physical properties including chemical resistance of the polyamide composition, and flame retardancy due to containing a halogen-free flame retardant Expression becomes difficult.
From the viewpoint of mechanical properties, heat resistance, chemical resistance, etc., the content of the naphthalenedicarboxylic acid unit in the dicarboxylic acid unit is preferably 50 mol% or more, more preferably 60 mol% or more, and 70% by mol or more. It is more preferably 80 mol % or more, even more preferably 90 mol % or more, and particularly preferably 100 mol %.

Examples of naphthalenedicarboxylic acid units include 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1 ,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, structural units derived from naphthalenedicarboxylic acid such as 2,7-naphthalenedicarboxylic acid. be done. Only one type of these structural units may be contained, or two or more types may be contained. Among the above naphthalenedicarboxylic acids, 2,6-naphthalenedicarboxylic acid is preferable from the viewpoint of chemical resistance and flame retardancy of the polyamide composition and reactivity with diamines.
From the same viewpoint as above, the content of structural units derived from 2,6-naphthalenedicarboxylic acid in naphthalenedicarboxylic acid units is preferably 90 mol% or more, more preferably 95 mol% or more. , 100 mol % (substantially 100 mol %) is preferable.

The dicarboxylic acid unit may contain structural units derived from dicarboxylic acids other than naphthalenedicarboxylic acid, as long as the effects of the present invention are not impaired.
Examples of other dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, dimethylmalonic acid, 2 , 2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, trimethyladipic acid and other aliphatic dicarboxylic acids; 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1, alicyclic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, cycloheptanedicarboxylic acid, cyclooctanedicarboxylic acid, cyclodecanedicarboxylic acid; terephthalic acid, isophthalic acid, diphenic acid, 4,4′-biphenyldicarboxylic acid, diphenylmethane-4, aromatic dicarboxylic acids such as 4'-dicarboxylic acid and diphenylsulfone-4,4'-dicarboxylic acid; 1 type of structural units derived from these other dicarboxylic acids may be contained, and 2 or more types may be contained.
The content of structural units derived from other dicarboxylic acids in dicarboxylic acid units is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less. , is more preferably 20 mol % or less, and even more preferably 10 mol % or less.

(diamine unit)
60 mol % or more and 100 mol % or less of the diamine units are branched aliphatic diamine units and straight-chain aliphatic diamine units as arbitrary constitutional units. That is, the diamine units either contain branched aliphatic diamine units and no linear aliphatic diamine units, or contain both branched and linear aliphatic diamine units, and the diamine The total content of branched aliphatic diamine units and linear aliphatic diamine units, which are optional structural units, is 60 mol % or more and 100 mol % or less. When the total content of the branched aliphatic diamine unit and the linear aliphatic diamine unit in the diamine unit is less than 60 mol%, the effect of improving various physical properties such as chemical resistance and flame retardancy in the polyamide composition is expressed. becomes difficult.
From the viewpoint of chemical resistance, mechanical properties, heat resistance, etc., the total content of the branched aliphatic diamine unit and the linear aliphatic diamine unit in the diamine unit is preferably 70 mol% or more, and 80 mol. % or more, more preferably 90 mol % or more, and particularly preferably 100 mol %.
In the present specification, the term "branched aliphatic diamine" refers to a linear aliphatic chain having carbon atoms at both ends which are carbon atoms to which two amino groups are respectively bonded. means an aliphatic diamine having a structure in which one or more of the hydrogen atoms in the aliphatic chain (the assumed aliphatic chain) of is replaced by a branched chain. Thus, for example, 1,2-propanediamine (H ₂ N—CH(CH ₃ )—CH ₂ —NH ₂ ) has one of the hydrogen atoms of the 1,2-ethylene group as the assumed aliphatic chain It is classified as a branched aliphatic diamine in the present specification because it has a structure substituted with a methyl group of .

In the diamine units, the ratio of branched aliphatic diamine units to 100 mol % of the total of branched aliphatic diamine units and linear aliphatic diamine units is 60 mol % or more. If the proportion of the branched aliphatic diamine units is less than 60 mol %, it will be difficult to achieve the effect of improving various physical properties such as chemical resistance and flame retardancy of the polyamide composition.
From the viewpoint of easily improving various physical properties such as chemical resistance and improving the moldability of the polyamide composition, the branched fat relative to the total 100 mol% of the branched aliphatic diamine unit and the linear aliphatic diamine unit The proportion of group diamine units is preferably 65 mol% or more, more preferably 70 mol% or more, even more preferably 72 mol% or more, and even more preferably 77 mol% or more. , is more preferably 80 mol % or more, and may be 90 mol % or more. In addition, the ratio may be 100 mol%, but considering the moldability and the availability of diamine, it is preferably 99 mol% or less, 98 mol% or less, further 95 mol% or less. may

The number of carbon atoms in the branched aliphatic diamine unit is preferably 4 or more, more preferably 6 or more, still more preferably 8 or more, and preferably 18 or less, and 12 or less. is more preferable. If the number of carbon atoms in the branched aliphatic diamine unit is within the above range, the polymerization reaction between the dicarboxylic acid and the diamine will proceed well, the crystallinity of the polyamide (A) will be good, and the polyamide composition containing the polyamide (A) will be obtained. The physical properties of things are easier to improve. Examples of preferred embodiments of the number of carbon atoms in the branched aliphatic diamine unit include 4 or more and 18 or less, 4 or more and 12 or less, 6 or more and 18 or less, 6 or more and 12 or less, or 8 or more and 18 or less. , 8 or more and 12 or less.

The type of branched chain in the branched aliphatic diamine unit is not particularly limited, and may be, for example, various aliphatic groups such as a methyl group, an ethyl group, and a propyl group. A structural unit derived from a diamine having at least one selected from the group consisting of a methyl group and an ethyl group as a chain is preferred. When a diamine having at least one selected from the group consisting of a methyl group and an ethyl group as a branched chain is used, the polymerization reaction between the dicarboxylic acid and the diamine proceeds well, and the chemical resistance of the polyamide composition containing the polyamide (A) is improved. performance can be improved more easily. From this point of view, the branched chain is more preferably a methyl group.
The number of branched chains of the branched aliphatic diamine that forms the branched aliphatic diamine unit is not particularly limited, but the number is preferably 3 or less because the effects of the present invention are exhibited more remarkably. , is more preferably two or less, and more preferably one.

Branched aliphatic diamine unit, when the carbon atom to which any one amino group is bonded is the 1st position, the carbon atom at the 2nd position adjacent to it (the carbon atom on the assumed aliphatic chain described above) and the 2nd position is preferably a structural unit derived from a diamine having at least one of the branched chains on at least one of the 3-position carbon atoms (carbon atoms on the assumed aliphatic chain) adjacent to the carbon atom of the above 2 Structural units derived from diamines having at least one of the branched chains at the carbon atoms of the positions are more preferred. As a result, various physical properties such as chemical resistance and flame retardancy of the polyamide composition are likely to be improved.

Examples of branched aliphatic diamine units include 1,2-propanediamine, 1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, 1-ethyl-1,4- Butanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2-methyl-1,3- Propanediamine, 2-methyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2 ,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine , 2,4-diethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-ethyl-1, 7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 1,3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8- octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1, 8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, 5-methyl-1,9-nonanediamine Structural units derived from branched aliphatic diamines such as Only one type of these structural units may be contained, or two or more types may be contained.
Among the branched aliphatic diamine units, 2-methyl-1,5-pentanediamine, 3-methyl-1, Structural units derived from at least one diamine selected from the group consisting of 5-pentanediamine, 2-methyl-1,8-octanediamine, and 2-methyl-1,9-nonanediamine are preferred, and 2-methyl-1 ,8-octanediamine is more preferred.

The number of carbon atoms in the linear aliphatic diamine unit is preferably 4 or more, more preferably 6 or more, still more preferably 8 or more, and preferably 18 or less, and 12 or less. It is more preferable to have When the number of carbon atoms in the linear aliphatic diamine unit is within the above range, the polymerization reaction between the dicarboxylic acid and the diamine proceeds well, the crystallinity of the polyamide is improved, and the physical properties of the polyamide are easily improved. Examples of preferred embodiments of the number of carbon atoms in the linear aliphatic diamine unit include 4 or more and 18 or less, 4 or more and 12 or less, 6 or more and 18 or less, 6 or more and 12 or less, or 8 or more and 18 or less. It may be 8 or more and 12 or less.
The number of carbon atoms in the linear aliphatic diamine unit and the branched aliphatic diamine unit may be the same or different. is preferably

Linear aliphatic diamine units include, for example, ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1 ,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1, Structural units derived from linear aliphatic diamines such as 15-pentadecanediamine, 1,16-hexadecanediamine, 1,17-heptadecanediamine, and 1,18-octadecanediamine can be mentioned. Only one type of these structural units may be contained, or two or more types may be contained.
Among the linear aliphatic diamine units, the effect of the present invention is exhibited more remarkably, and from the viewpoint of improving the heat resistance of the polyamide composition containing the obtained polyamide (A) in particular, 1,4-butane is used. diamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine, preferably a structural unit derived from at least one diamine, and more preferably a structural unit derived from 1,9-nonanediamine.

The diamine unit can contain structural units derived from diamines other than branched aliphatic diamines and linear aliphatic diamines, as long as the effects of the present invention are not impaired. Examples of other diamines include alicyclic diamines and aromatic diamines.
Alicyclic diamines include, for example, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornanedimethylamine, tricyclodecanedimethyldiamine, and the like.
Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,4 '-diaminodiphenyl ether and the like.
1 type of structural units derived from these other diamines may be contained, and 2 or more types may be contained.
The content of structural units derived from other diamines in the diamine unit is preferably 30 mol % or less, more preferably 20 mol % or less, and even more preferably 10 mol % or less.

(Dicarboxylic acid unit and diamine unit)
The molar ratio of dicarboxylic acid units to diamine units [dicarboxylic acid units/diamine units] in the polyamide (A) is preferably from 45/55 to 55/45. When the molar ratio of the dicarboxylic acid unit to the diamine unit is within the above range, the polymerization reaction proceeds favorably, and a polyamide composition having desired excellent physical properties can be easily obtained.
The molar ratio between the dicarboxylic acid units and the diamine units can be adjusted according to the compounding ratio (molar ratio) between the starting dicarboxylic acid and the starting diamine.

The total ratio of dicarboxylic acid units and diamine units in the polyamide (A) (the ratio of the total number of moles of dicarboxylic acid units and diamine units to the number of moles of all structural units constituting the polyamide (A)) is 70 mol% or more. preferably 80 mol % or more, more preferably 90 mol % or more, 95 mol % or more, or even 100 mol %. When the total ratio of the dicarboxylic acid units and the diamine units is within the above range, the polyamide composition will have more excellent physical properties than desired.

(aminocarboxylic acid unit)
Polyamide (A) may further contain aminocarboxylic acid units in addition to dicarboxylic acid units and diamine units.
Examples of aminocarboxylic acid units include structural units derived from lactams such as caprolactam and lauryllactam; aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. The content of aminocarboxylic acid units in the polyamide (A) is preferably 40 mol% or less, preferably 20 mol% or less, relative to the total 100 mol% of the dicarboxylic acid units and diamine units constituting the polyamide (A). is more preferable.

(Polyvalent carboxylic acid unit)
Polyamide (A) contains structural units derived from trivalent or higher polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid, etc. within a range that does not impair the effects of the present invention. can also be included with

(terminal blocker unit)
The polyamide (A) may contain structural units derived from a terminal blocker (terminal blocker units).
The terminal blocker unit is preferably 1.0 mol% or more, more preferably 1.2 mol% or more, and 1.5 mol% or more with respect to 100 mol% of the diamine unit. is more preferably 10 mol % or less, more preferably 7.5 mol % or less, and even more preferably 6.5 mol % or less. When the content of the terminal blocker unit is within the above range, the polyamide composition is excellent in mechanical strength and fluidity. The content of the terminal blocking agent unit can be set within the above desired range by appropriately adjusting the amount of the terminal blocking agent when charging the polymerization raw material. Considering volatilization of the monomer components during polymerization, the charging amount of the terminal blocker should be finely adjusted so that the desired amount of terminal blocker units are introduced into the resulting polyamide (A). is desirable.
As a method for determining the content of terminal blocker units in the polyamide (A), for example, as shown in JP-A-7-228690, the solution viscosity is measured, and the number average molecular weight is calculated. A method of calculating the total amount of terminal groups from the relational expression and subtracting the amount of amino groups and the amount of carboxyl groups obtained by titration from this, or using ¹ H-NMR, signals corresponding to each of the diamine unit and the terminal blocker unit. and the like, and the latter is preferable.

A monofunctional compound having reactivity with a terminal amino group or a terminal carboxyl group can be used as the terminal blocking agent. Specific examples include monocarboxylic acids, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, and monoamines. From the viewpoint of reactivity and stability of the terminal to be blocked, monocarboxylic acid is preferable as the terminal blocking agent for the terminal amino group, and monoamine is preferable as the terminal blocking agent for the terminal carboxyl group. From the standpoint of ease of handling, etc., monocarboxylic acids are more preferable as terminal blocking agents.

The monocarboxylic acid used as a terminal blocking agent is not particularly limited as long as it is reactive with amino groups, and examples thereof include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, and laurin. acids, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, aliphatic monocarboxylic acids such as isobutyric acid; alicyclic monocarboxylic acids such as cyclopentanecarboxylic acid and cyclohexanecarboxylic acid; benzoic acid, toluic acid, aromatic monocarboxylic acids such as α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; and any mixture thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, and stearic acid are preferred in terms of reactivity, stability of blocked ends, and price. , and benzoic acid are preferred.

The monoamine used as the terminal blocking agent is not particularly limited as long as it has reactivity with carboxyl groups. Examples include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, and stearyl. Aliphatic monoamines such as amine, dimethylamine, diethylamine, dipropylamine and dibutylamine; Alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; Aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; Mixtures of any of these can be mentioned. Among these, at least one selected from the group consisting of butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline in terms of reactivity, high boiling point, stability of capped ends, and price. is preferred.

The polyamide (A) preferably has an intrinsic viscosity [η _inh ] of 0.1 dl/g or more, measured at a concentration of 0.2 g/dl and a temperature of 30° C., using concentrated sulfuric acid as a solvent, and 0.4 dl/g or more. more preferably 0.6 dl/g or more, particularly preferably 0.8 dl/g or more, and preferably 3.0 dl/g or less, and 2.0 dl/g /g or less, more preferably 1.8 dl/g or less. When the intrinsic viscosity [η _inh ] of the polyamide (A) is within the above range, various physical properties such as moldability are further improved. The intrinsic viscosity [η _inh ] is determined by the flowing time t ₀ (seconds) of the solvent (concentrated sulfuric acid), the flowing time t ₁ (seconds) of the sample solution, and the sample concentration c (g/dl) in the sample solution (i.e., 0.2 g /dl) by the relational expression η _inh =[ln(t ₁ /t ₀ )]/c.

The melting point of the polyamide (A) is not particularly limited, and can be, for example, 260° C. or higher, 270° C. or higher, or even 280° C. or higher. ° C. or higher, more preferably 295 ° C. or higher, more preferably 300 ° C. or higher, even more preferably 305 ° C. or higher, even more preferably 310 ° C. or higher, It may be 315°C or higher. Although the upper limit of the melting point of the polyamide (A) is not particularly limited, it is preferably 330° C. or less, more preferably 320° C. or less, and even more preferably 317° C. or less in consideration of moldability. . The melting point of the polyamide (A) can be obtained as the peak temperature of the melting peak that appears when the temperature is raised at a rate of 10 ° C./min using a differential scanning calorimetry (DSC) device. It can be obtained by the method described.

The glass transition temperature of the polyamide (A) is not particularly limited, and can be, for example, 100° C. or higher, 110° C. or higher, or even 120° C. or higher. , preferably 125° C. or higher, more preferably 130° C. or higher, even more preferably 135° C. or higher, even more preferably 137° C. or higher, and even more preferably 138° C. or higher. Preferably, it may be 139° C. or higher. The upper limit of the glass transition temperature of the polyamide (A) is not particularly limited, but considering moldability etc., it is preferably 180 ° C. or less, more preferably 160 ° C. or less, and 150 ° C. or less. More preferred. The glass transition temperature of the polyamide (A) can be obtained as the temperature of the inflection point that appears when the temperature is raised at a rate of 20 ° C./min using a differential scanning calorimetry (DSC) device. It can be obtained by the method described in the example.

(Method for producing polyamide (A))
The polyamide (A) can be produced by any method known as a method for producing a crystalline polyamide. It can be produced by a method such as an extrusion polymerization method. Among these, the method for producing polyamide (A) is preferably a solid-phase polymerization method from the viewpoint of being able to better suppress thermal deterioration during polymerization.
In order to set the molar ratio of the branched aliphatic diamine unit to the straight-chain aliphatic diamine unit within the specific numerical range described above, the branched aliphatic diamine and the straight-chain aliphatic diamine used as raw materials are desirably may be used at a compounding ratio that provides a molar ratio of the above units.
When 2-methyl-1,8-octanediamine and 1,9-nonanediamine, for example, are used as the branched aliphatic diamine and linear aliphatic diamine, respectively, these can be produced by known methods. Known methods include, for example, a method of distilling a diamine crude reaction liquid obtained by a reductive amination reaction using a dialdehyde as a starting material. Furthermore, 2-methyl-1,8-octanediamine and 1,9-nonanediamine can be obtained by fractionating the diamine crude reaction liquid.

For the polyamide (A), for example, a diamine, a dicarboxylic acid, and, if necessary, a catalyst or a terminal blocking agent are added all at once to produce a nylon salt, and then heated and polymerized at a temperature of 200 to 250 ° C. It can be produced by preparing a prepolymer by heating and then solid-phase polymerizing it, or by polymerizing it using a melt extruder. When the final stage of polymerization is carried out by solid phase polymerization, it is preferably carried out under reduced pressure or under inert gas flow. Coloring and gelation can be effectively suppressed. When the final stage of polymerization is carried out using a melt extruder, the polymerization temperature is preferably 370° C. or less. Polymerization under such conditions yields a polyamide with little degradation and little decomposition.

Examples of catalysts that can be used in producing the polyamide (A) include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts or esters thereof. Examples of the above salts or esters include phosphoric acid, phosphorous acid, or hypophosphorous acid and potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony, and the like. Salt with metal; Ammonium salt of phosphoric acid, phosphorous acid or hypophosphite; Ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, octadecyl ester of phosphoric acid, phosphorous acid or hypophosphorous acid , decyl ester, stearyl ester, phenyl ester, and the like.
The amount of the catalyst used is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and 1.0% by mass or less with respect to 100% by mass of the total mass of the raw materials. and more preferably 0.5% by mass or less. If the amount of the catalyst used is at least the above lower limit, the polymerization proceeds satisfactorily. If the content is not more than the above upper limit, catalyst-derived impurities are less likely to occur, and for example, when the polyamide composition is made into a film, problems caused by the above impurities can be prevented.

[Halogen-free flame retardant (B)]
The polyamide composition of the present invention contains a halogen-free flame retardant (B). By including the halogen-free flame retardant (B), the flame retardancy of the polyamide composition can be improved while reducing the environmental load. The halogen-free flame retardant (B) is not particularly limited, and compounds known as halogen-free flame retardants can be used. As the halogen-free flame retardant (B), a phosphorus-based flame retardant containing elemental phosphorus can be preferably used. , (poly)phosphate-based flame retardants, phosphazene-based flame retardants, phosphine-based flame retardants, and the like. Among these, phosphine-based flame retardants are preferred.
Phosphine-based flame retardants include, for example, monophosphinates and diphosphinates (both may be collectively abbreviated as "phosphinates" hereinafter).
These may be used individually by 1 type, and may use 2 or more types together.

Monophosphinates include, for example, compounds represented by the following general formula (1).

Diphosphinates include, for example, compounds represented by the following general formula (2).

In general formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aryl group having 7 carbon atoms. represents an arylalkyl group of ∼20. R ⁵ represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 7 to 20 carbon atoms or an arylalkylene group having 7 to 20 carbon atoms. M represents calcium (ion), magnesium (ion), aluminum (ion) or zinc (ion). m is 2 or 3, n is 1 or 3, and x is 1 or 2.

The above alkyl groups include linear or branched saturated aliphatic groups. The above aryl groups may be unsubstituted or substituted with various substituents such as phenyl, benzyl, o-toluyl and 2,3-xylyl groups.

As described in European Patent Application Publication No. 699708 and Japanese Patent Application Laid-Open No. 8-73720, the above phosphinate is a phosphinic acid and a metal such as a metal carbonate, metal hydroxide, or metal oxide. It can be made in aqueous solution using the ingredients. These are usually monomeric compounds, but may also contain polymeric phosphinates with a degree of condensation of 1-3 under certain circumstances, depending on the reaction conditions.

Examples of monophosphinic acids and diphosphinic acids constituting phosphinates include dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, methanedi(methylphosphinic acid), benzene-1,4- di(methylphosphinic acid), methylphenylphosphinic acid, diphenylphosphinic acid and the like.

Examples of metal components constituting the phosphinate include calcium ions, magnesium ions, aluminum ions and zinc ions.

Specific phosphinates include, for example, calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, ethyl zinc methylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, methyl-n-propylphosphinate Aluminum, zinc methyl-n-propylphosphinate, calcium methylenebis(methylphosphinate), magnesium methylenebis(methylphosphinate), aluminum methylenebis(methylphosphinate), zinc methylenebis(methylphosphinate), phenylene-1,4-bis (methylphosphinate) calcium, phenylene-1,4-bis(methylphosphinate) magnesium, phenylene-1,4-bis(methylphosphinate) aluminum, phenylene-1,4-bis(methylphosphinate) zinc, methyl calcium phenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, zinc diphenylphosphinate and the like.

Among them, from the viewpoint of the flame retardancy and electrical properties of the resulting polyamide composition and the availability of the phosphinate, calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, ethylmethyl Aluminum phosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate are preferred. These phosphinates may be used individually by 1 type, and may use 2 or more types together.

The phosphinate is pulverized so that the average particle size of the phosphinate is 100 μm or less in terms of the mechanical properties (toughness, rigidity, etc.) of the polyamide composition and the molded product made of it, and the appearance of the molded product. It is preferable to use powder, and it is more preferable to use powder pulverized to a size of 50 μm or less. It is preferable to use a powdery phosphinate having an average particle size of, for example, about 0.5 to 20 μm, because not only can a polyamide composition having excellent flame retardancy be obtained, but also the rigidity of molded articles can be improved.
In this specification, the average particle size is a value measured with a laser diffraction particle size distribution device.

The phosphinate does not necessarily have to be completely pure, and may contain unreacted substances or by-products to the extent that the effects of the present invention are not impaired.

The content of the halogen-free flame retardant (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and 20 parts by mass or more with respect to 100 parts by mass of the polyamide (A). It is more preferably 25 parts by mass or more, more preferably 100 parts by mass or less, more preferably 75 parts by mass or less, and even more preferably 70 parts by mass or less. , 50 parts by mass or less, and even more preferably 30 parts by mass or less. When the content of the halogen-free flame retardant (B) is at least the above lower limit, a polyamide composition having excellent flame retardancy can be obtained. In addition, if the content of the halogen-free flame retardant (B) is equal to or less than the above upper limit, generation of decomposition gas during melt-kneading, deterioration of fluidity during molding (especially thin-wall fluidity), In addition, it is possible to suppress deterioration of mechanical properties and external appearance of molded products. When using multiple types of halogen-free flame retardants (B), the total amount thereof should be within the above range.

According to the studies of the present inventors, regarding the polyamide constituting the polyamide composition, if more than 40 mol% of the dicarboxylic acid units constituting the polyamide are naphthalene dicarboxylic acid units, 40 mol of the dicarboxylic acid units constituting the polyamide It has been found that the combination of a halogen-free flame retardant and a polyamide tends to improve flame retardancy more than when the % is terephthalic acid units. It has also been found that this tendency appears regardless of the ratio of linear aliphatic diamine units to branched aliphatic diamine units in the diamine units constituting the polyamide. Thus, for example, assuming applications in which only the importance of certain physical properties of the semi-aromatic polyamide is desired, the ratio of branched aliphatic diamine units to the ratio of linear aliphatic diamine units in the diamine units When a polyamide composition is produced using a polyamide having a larger molecular weight and a halogen-free flame retardant, it may be possible to obtain a polyamide composition having both the specific physical properties and flame retardancy.

[Filler (C)]
The polyamide composition of the present invention may contain filler (C). By using the filler (C), it is possible to obtain a thin polyamide composition having excellent flame retardancy, heat resistance, moldability, and mechanical strength.

As the filler (C), those having various forms such as fibrous, tabular, needle-like, powdery and cloth-like can be used. Specifically, inorganic or organic fibrous fillers such as glass fiber, carbon fiber, wholly aromatic polyamide fiber (aramid fiber), liquid crystal polymer (LCP) fiber, gypsum fiber, brass fiber, ceramic fiber, boron whisker fiber, etc. (C1); Flat fillers such as glass flakes, mica and talc; Needle-shaped fillers such as potassium titanate whiskers, aluminum borate whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, wollastonite, sepiolite, xonotlite, and zinc oxide whiskers Filler (C2); silica, silica alumina, alumina, barium carbonate, magnesium carbonate, aluminum nitride, boron nitride, potassium titanate, titanium oxide, magnesium hydroxide, aluminum silicate (kaolin, clay, pyrophyllite, bentonite) , calcium silicate, magnesium silicate (attapulgite), aluminum borate, calcium sulfate, barium sulfate, magnesium sulfate, asbestos, glass beads, carbon black, graphene, graphite, carbon nanotubes, silicon carbide, sericite, hydrotalcite, powdery fillers such as montmorillonite, molybdenum disulfide, ultra-high molecular weight polyethylene particles, phenolic resin particles, crosslinked styrene resin particles, crosslinked acrylic resin particles; cloth fillers such as glass cloth; These may be used individually by 1 type, and may use 2 or more types together.

The surface of the filler (C) is coated with polymer compounds such as silane coupling agents, titanium coupling agents, acrylic resins, urethane resins, and epoxy resins for the purpose of enhancing dispersibility and adhesion in the polyamide (A). Alternatively, it may be surface-treated with other low-molecular-weight compounds.

Among the fillers (C), at least one selected from the group consisting of fibrous fillers (C1) and acicular fillers (C2) because it is low in cost and gives molded articles with high mechanical strength. is preferred. From the viewpoint of high strength and low cost, the fibrous filler (C1) is preferable, and glass fiber is more preferable. The needle-like filler (C2) is preferable from the viewpoint of obtaining a molded article with high surface smoothness.
The fibrous filler (C1) and the needle-like filler (C2) are preferably at least one selected from the group consisting of glass fibers, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, and aluminum borate whiskers. , glass fiber and wollastonite, more preferably glass fiber.

The fibrous filler (C1) preferably has an average fiber length of 1 to 10 mm, more preferably 1 to 7 mm, still more preferably 2 to 4 mm. Also, the average fiber diameter of the fibrous filler (C1) is preferably 6 to 20 μm, more preferably 6 to 15 μm, from the viewpoint of obtaining mechanical strength.
The average fiber length and average fiber diameter of the fibrous filler (C1) are obtained by measuring the fiber length and fiber diameter of 400 arbitrarily selected fibrous fillers (C1) by image analysis using an electron microscope. , can be obtained by calculating the mass average value of each.
In addition, the average fiber length and average fiber diameter of the fibrous filler (C1) in the polyamide composition or in the molded article formed by molding the polyamide composition is, for example, the polyamide composition or the molded article in an organic solvent is dissolved, the fibrous filler (C1) is extracted, and it can be obtained by image analysis using an electron microscope in the same manner as described above.

The cross-sectional shape of the fibrous filler (C1) and the needle-like filler (C2) includes, for example, a rectangular shape, an oval shape close to a rectangle, an elliptical shape, a cocoon shape, and a cocoon shape with a constricted central portion in the longitudinal direction. . Among them, the cross-sectional shape of the fibrous filler (C1) and the needle-like filler (C2) is preferably a rectangle, an oval shape close to a rectangle, an ellipse, or a cocoon shape.

When the fibrous filler (C1) is glass fiber, specific compositions include an E glass composition, a C glass composition, an S glass composition, an alkali-resistant glass composition, and the like. Also, the tensile strength of the glass fiber is arbitrary, but usually 290 kg/mm ² or more. Among them, E glass is preferable from the viewpoint of easy availability. These glass fibers are preferably surface-treated with a silane coupling agent such as γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane. The adhered amount is usually 0.01% by mass or more based on the mass of the glass fiber (the total amount of the glass fiber and the surface treatment agent).

The content of the filler (C) is preferably 0.1 parts by mass or more and 200 parts by mass or less, more preferably 1 part by mass or more and 180 parts by mass or less, relative to 100 parts by mass of the polyamide (A), More preferably, it is 5 parts by mass or more and 150 parts by mass or less. By setting the content of the filler (C) to 0.1 parts by mass or more with respect to 100 parts by mass of the polyamide (A), the toughness and mechanical strength of the polyamide composition of the present invention are improved, and the content By setting the amount to 200 parts by mass or less, a polyamide composition having excellent moldability can be obtained.

[Other additives]
The polyamide composition may optionally contain other additives in addition to the above-mentioned polyamide (A), halogen-free flame retardant (B), and optionally used filler (C).

Other additives include, for example, organic heat stabilizers such as phenol heat stabilizers, phosphorus heat stabilizers, sulfur heat stabilizers, and amine heat stabilizers; heat stabilizers such as copper compounds; coloring agents. UV absorber; Light stabilizer; Antistatic agent; Flame retardant aid; Crystal nucleating agent; Plasticizer; Lubricant; , impact modifiers such as rubber; and anti-drip agents such as fluororesins. Except for the fluorine-based resin as an anti-drip agent, other additives preferably do not contain halogen.

The content of the other additives is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 0.02 to 200 parts by weight, preferably 0.03 to 100 parts by weight, based on 100 parts by weight of the polyamide (A). Parts by mass are more preferred.

[Method for producing polyamide composition]
The method for producing the polyamide composition is not particularly limited, and the polyamide (A), the halogen-free flame retardant (B), and the filler (C) and other additives used as necessary are uniformly mixed. can be preferably adopted. For mixing, a method of melt-kneading using a single-screw extruder, twin-screw extruder, kneader, Banbury mixer, or the like is preferably adopted. Although the melt-kneading conditions are not particularly limited, for example, a method of melt-kneading for about 1 to 30 minutes at a temperature range about 10 to 50° C. higher than the melting point of the polyamide (A) can be mentioned.

<Molded product>
(Molding method)
A molded article made of the polyamide composition of the present invention can be produced by using the polyamide composition of the present invention through injection molding, blow molding, extrusion molding, compression molding, stretch molding, vacuum molding, foam molding, It can be obtained by molding by various molding methods such as a rotational molding method, an impregnation method, a laser sintering method, and a hot-melt lamination method. Furthermore, the polyamide composition of the present invention and other polymers can be composite-molded to obtain molded articles.

(Application)
Examples of the molded products include films, sheets, tubes, pipes, gears, cams, various housings, rollers, impellers, bearing retainers, spring holders, clutch parts, chain tensioners, tanks, wheels, connectors, switches, sensors, and sockets. , capacitors, hard disk components, jacks, fuse holders, relays, coil bobbins, resistors, IC housings, LED reflectors, etc.
In particular, the polyamide composition of the present invention is useful for injection molded parts, heat-resistant films, tubes for transporting various drugs/chemicals, intake pipes, blow-by tubes, substrates for 3D printers, etc., which require high-temperature properties, chemical resistance, and flame retardancy. It is also suitable for automotive molded products that require high heat resistance and chemical resistance, such as interior and exterior parts of automobiles, parts in the engine room, cooling system parts, sliding parts, electrical parts, etc. can be used for In addition, the polyamide composition of the present invention can be used as molded articles that require heat resistance corresponding to electric parts, electronic parts, and surface mounting processes. Such molded products include surface-mounted connectors, sockets, camera modules, power supply parts, switches, sensors, capacitor base plates, hard disk parts, relays, resistors, fuse holders, coil bobbins, surface-mounted parts such as IC housings, etc. can be suitably used for

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

Each evaluation in Production Examples, Examples, and Comparative Examples was performed according to the methods shown below.
• Intrinsic Viscosity The intrinsic viscosity (dl/g) of the polyamide (sample) obtained in the Production Example at a concentration of 0.2 g/dl and a temperature of 30° C. using concentrated sulfuric acid as a solvent was obtained from the following relational expression.
η _inh =[ln(t ₁ /t ₀ )]/c
In the above relational expression, η _inh represents the intrinsic viscosity (dl / g), t ₀ represents the flow time (seconds) of the solvent (concentrated sulfuric acid), t ₁ represents the flow time (seconds) of the sample solution, and c represents the concentration (g/dl) of the sample in the sample solution (ie 0.2 g/dl).

-Melting point and glass transition temperature The melting point and glass transition temperature of the polyamides obtained in Production Examples were measured using a differential scanning calorimeter "DSC7020" manufactured by Hitachi High-Tech Science Co., Ltd.
The melting point was measured according to ISO11357-3 (2nd edition, 2011). Specifically, in a nitrogen atmosphere, the sample (polyamide) was heated from 30 ° C. to 340 ° C. at a rate of 10 ° C./min, held at 340 ° C. for 5 minutes to completely melt the sample, and then heated to 10 ° C. /min to 50°C and held at 50°C for 5 minutes. The peak temperature of the melting peak that appears when the temperature is again raised to 340°C at a rate of 10°C/min is the melting point (°C), and if there are multiple melting peaks, the peak temperature of the highest melting peak is the melting point (°C). did.
The glass transition temperature (° C.) was measured according to ISO 11357-2 (2nd edition, 2013). Specifically, in a nitrogen atmosphere, the sample (polyamide) was heated from 30 ° C. to 340 ° C. at a rate of 20 ° C./min, held at 340 ° C. for 5 minutes to completely melt the sample, and then heated to 20 ° C. /min to 50°C and held at 50°C for 5 minutes. The temperature at the inflection point when the temperature was again raised to 200°C at a rate of 20°C/min was taken as the glass transition temperature (°C).

• Flame retardancy The flame retardancy was evaluated according to the UL-94 standard.
Using an injection molding machine manufactured by Nissei Plastic Industry Co., Ltd. (mold clamping force: 80 tons, screw diameter: φ26 mm), using the polyamide compositions obtained in Examples and Comparative Examples, 20 degrees below the melting point of the polyamide. With a cylinder temperature higher by ~30 ° C., the polyamide compositions of Example 1 and Comparative Example 1 under the condition of a mold temperature of 160 ° C., and the polyamide compositions of Comparative Examples 2 and 3 under the condition of a mold temperature of 140 ° C., A polyamide composition was molded using a T-runner mold to obtain a test piece having a thickness of 0.4 mm, a width of 13 mm and a length of 125 mm.
Then, the upper end of the obtained test piece is clamped to fix the test piece vertically, and the lower end is exposed to a predetermined blue flame with a height of 20 ± 1 mm for 10 seconds and released, and the burning time of the test piece (first time) was measured. As soon as the fire is extinguished, the lower end is exposed to the flame again and separated, and the burning time (second time) of the test piece is measured. The same measurement was repeated for 5 pieces, and a total of 10 data, 5 data of the first burning time and 5 data of the second burning time, were obtained. The total of 10 data was defined as T, and the maximum value among the 10 data was defined as M, and evaluation was made according to the following evaluation criteria.
In addition, the presence or absence of drip during contact with the flame was visually confirmed.
〔Evaluation criteria〕
V-0: T less than 50 seconds and M less than 10 seconds, did not flare up to the clamp, and did not ignite cotton 12 inches below when the flaming melt fell.
V-1: T less than 250 seconds and M less than 30 seconds, did not flare up to the clamp, and did not ignite cotton 12 inches below when the flaming melt fell.
V-2: T less than 250 seconds and M less than 30 seconds did not flare up to the clamp and the flaming melt fell and ignited the cotton 12 inches below.
x: When none of the above UL94 evaluation criteria is met.

· Blister resistance Using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (clamping force: 18 tons, screw diameter: φ18 mm), using the polyamide compositions obtained in Examples and Comparative Examples, polyamide The cylinder temperature is 20 to 30 ° C. higher than the melting point of the polyamide compositions of Example 1 and Comparative Example 1 under the condition of a mold temperature of 160 ° C., and the polyamide compositions of Comparative Examples 2 and 3 have a mold temperature of 140 ° C. The polyamide composition was molded (injection molded) using a T-runner mold under the conditions of , to prepare a test piece (sheet) having a length of 30 mm, a width of 10 mm and a thickness of 1 mm.
The obtained test piece was allowed to stand under conditions of a temperature of 85° C. and a relative humidity of 85% for 168 hours. After that, a reflow test was performed on the test piece using an infrared heating furnace (manufactured by Sanyo Seiko Co., Ltd., SMT Scope). In the reflow test, the temperature was raised from 25° C. to 150° C. in 60 seconds, then raised to 180° C. in 90 seconds, further raised to the peak temperature in 60 seconds, and held at the peak temperature for 20 seconds. did. The reflow test was performed by changing the peak temperature from 250°C to 270°C in increments of 10°C. After completing the reflow test, the appearance of the test piece was visually observed. The limit temperature at which the test piece does not melt and blister does not occur is defined as the blister resistance temperature. was indicated as "Δ", and the case where the blister resistance temperature was lower than 250° C. was indicated as "x", which was used as an index of blister resistance. If it is "○" or "△", it is a practically acceptable level.

<<Preparation of test piece>>
Using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (clamping force: 100 tons, screw diameter: φ32 mm), using the polyamide compositions obtained in Examples and Comparative Examples, the melting point of polyamide The cylinder temperature is 20 to 30 ° C. higher, the polyamide compositions of Example 1 and Comparative Example 1 under the condition of a mold temperature of 160 ° C., and the polyamide compositions of Comparative Examples 2 and 3 under the conditions of a mold temperature of 140 ° C. , Molding a polyamide composition using a T runner mold, multi-purpose test piece type A1 (dumbbell-shaped test piece described in JIS K7139; 4 mm thickness, total length 170 mm, parallel part length 80 mm, parallel part width 10 mm) made.

・ Tensile breaking strength Using the multi-purpose test piece type A1 (4 mm thickness) prepared by the above method, Autograph (manufactured by Shimadzu Corporation) is used in accordance with ISO527-1 (2012 2nd edition). Then, the tensile strength at break (MPa) at 23°C was measured.

· Heat distortion temperature A test piece (4 mm thick, total length 80 mm, width 10 mm) is prepared by cutting from the multi-purpose test piece type A1 (4 mm thick) prepared by the above method, and an HDT tester manufactured by Toyo Seiki Seisakusho Co., Ltd. S-3M” was used to measure the heat distortion temperature (° C.) in accordance with ISO75 (3rd edition, 2013).

- Water absorption A multi-purpose test piece type A1 (4 mm thick) prepared by the above method was weighed. Then, it was immersed in water, and after immersion treatment at 23° C. for 168 hours, it was weighed again to obtain the amount of weight increase, which was divided by the weight before immersion to obtain the water absorption (%).

Components used to prepare polyamide compositions in Examples and Comparative Examples are shown.

"polyamide"
[Production Example 1]
・Production of semi-aromatic polyamide (PA9N-1) 2,6-naphthalene dicarboxylic acid 9110.2 g (42.14 mol), a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [former/ The latter = 4/96 (molar ratio)] 6853.7 g (43.30 mol), 210.0 g (1.72 mol) of benzoic acid, 16.2 g of sodium hypophosphite monohydrate (to the total mass of raw materials 0.1% by mass of the content) and 8.3 liters of distilled water were placed in an autoclave having an internal volume of 40 liters, and the autoclave was purged with nitrogen. The mixture was stirred at 100°C for 30 minutes, and the temperature inside the autoclave was raised to 220°C over 2 hours. At this time, the pressure inside the autoclave increased to 2 MPa. Heating was continued for 5 hours while maintaining the pressure at 2 MPa, and water vapor was gradually removed to allow the reaction to proceed. Next, the pressure was lowered to 1.3 MPa over 30 minutes, and the reaction was continued for 1 hour to obtain a prepolymer. The resulting prepolymer was dried at 100° C. under reduced pressure for 12 hours and pulverized to a particle size of 2 mm or less. This was solid phase polymerized at 230° C. and 13 Pa (0.1 mmHg) for 10 hours to obtain a polyamide. This polyamide is abbreviated as "PA9N-1".

[Production Example 2]
・Production of semi-aromatic polyamide (PA9T-1) 8190.7 g (49.30 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [former/latter = 85/15 (molar ratio)] 7969.4 g (50.35 mol), 171.0 g (1.40 mol) of benzoic acid, 16.3 g of sodium hypophosphite monohydrate (0.1 g relative to the total mass of raw materials) mass%) and 5.5 liters of distilled water were placed in an autoclave having an internal volume of 40 liters, and the procedure was followed in the same manner as in Production Example 1 to obtain a polyamide. This polyamide is abbreviated as "PA9T-1".

《Halogen-free flame retardant》
Halogen-free metal phosphinate flame retardant ("Exolit OP1230" manufactured by Clariant Chemicals)
"filler"
・Glass fiber (1)
Glass fiber (“CS-3J256S” manufactured by Nitto Boseki Co., Ltd.)
・Glass fiber (2)
Glass fiber ("CSH3PA870S" manufactured by Nitto Boseki Co., Ltd.)

《Other Additives》
・Heat stabilizer (1)
Phosphorus heat stabilizer ("Irgafos 168" manufactured by BASF)
・Heat stabilizer (2)
Hindered phenol-based heat stabilizer ("Irganox 1098" manufactured by BASF)
・Heat stabilizer (3)
Phenolic heat resistant stabilizer ("SUMILIZER GA-80" manufactured by Sumitomo Chemical Co., Ltd.)
・Lubricant Low molecular weight polyolefin lubricant ("HiWAX 200P" manufactured by Mitsui Chemicals, Inc.)
・Crystal nucleating agent talc (“TALC #5000S” manufactured by Fuji Talc Industry Co., Ltd.)

[Example 1 and Comparative Examples 1 to 3]
Each component other than the filler is premixed in the ratio shown in Table 1, and fed from the upstream hopper of the twin-screw extruder ("BTN-32" manufactured by Plastic Engineering Laboratory Co., Ltd.), and the downstream side of the extruder. The filler was fed from the side feed port in the ratio shown in Table 1. The mixture was melt-kneaded at a cylinder temperature 20 to 30° C. higher than the melting point of the polyamide, extruded, cooled and cut to produce a polyamide composition in the form of pellets.

Using the polyamide compositions obtained in the above Examples and Comparative Examples, the various physical properties described above were evaluated. Table 1 shows the results.
In Table 1, C9DA indicates a 1,9-nonanediamine unit and MC8DA indicates a 2-methyl-1,8-octanediamine unit.

From Table 1, the polyamide composition of Example 1 has excellent flame retardancy and a small amount of deformation in the combustion test compared to Comparative Examples 1 to 3, and also has equivalent or higher blister resistance. I understand. Moreover, since the flame retardant itself is halogen-free, it is possible to improve the flame retardancy of the polyamide composition while reducing the environmental load.
The polyamide composition of Example 1 has equivalent or better evaluations of tensile strength at break, heat distortion temperature, and water absorption than those of Comparative Examples 1 to 3, and the polyamide composition of the present invention has mechanical properties. , heat resistance, and low water absorption.
As described in Patent Document 1, it is known that the use of an aliphatic diamine having a side chain lowers the crystallinity of the resulting polyamide, which is undesirable in terms of heat resistance, chemical resistance, and the like. . On the other hand, in the polyamide composition of the present invention, the polyamide (A) contained therein has dicarboxylic acid units mainly composed of naphthalenedicarboxylic acid units and diamine units mainly composed of branched aliphatic diamine units. By having the structure of, the chemical resistance is further improved, and in addition, various physical properties such as mechanical properties, heat resistance, and low water absorption are excellent.

Claims (15)

Containing a polyamide (A) having a dicarboxylic acid unit and a diamine unit and a halogen-free flame retardant (B),
More than 40 mol% and 100 mol% or less of the dicarboxylic acid units are naphthalene dicarboxylic acid units,
60 mol % to 100 mol % of the diamine units are branched aliphatic diamine units having 6 to 12 carbon atoms and linear aliphatic diamine units having 4 to 12 carbon atoms as optional structural units, and the branched The branched chain in the aliphatic diamine unit is a methyl group, and the ratio of the branched aliphatic diamine unit to the total 100 mol% of the branched aliphatic diamine unit and the linear aliphatic diamine unit is 72 mol % or more, the polyamide composition. 2. The ratio of the branched aliphatic diamine unit to 100 mol % of the total of the branched aliphatic diamine unit and the linear aliphatic diamine unit is 72 mol % or more and 99 mol % or less according to claim 1 Polyamide composition. 2. The ratio of the branched aliphatic diamine unit to 100 mol % of the total of the branched aliphatic diamine unit and the linear aliphatic diamine unit is 80 mol % or more and 99 mol % or less according to claim 1 Polyamide composition. The polyamide composition according to any one of claims 1 to 3, wherein the branched aliphatic diamine unit has 8 to 12 carbon atoms. The branched aliphatic diamine unit is derived from a diamine having a branched chain at least one of the carbon atom at the 2-position and the carbon atom at the 3-position when the carbon atom to which any one amino group is bonded is the 1-position. The polyamide composition according to any one of claims 1 to 4 , which is a structural unit for The branched aliphatic diamine units are 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2-methyl-1,8-octanediamine, and 2-methyl-1,9 - The polyamide composition according to any one of claims 1 to 3, which is a structural unit derived from at least one diamine selected from the group consisting of nonanediamine. The polyamide composition according to any one of claims 1 to 6 , wherein the linear aliphatic diamine unit has 6 or more and 12 or less carbon atoms. The linear aliphatic diamine unit is 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine , 1,10-decanediamine, 1,11-undecanediamine, and 1,12 - dodecanediamine. A polyamide composition according to any one of claims 1 to 3. The polyamide composition according to any one of claims 1 to 8 , which contains 5 parts by mass or more and 100 parts by mass or less of the halogen-free flame retardant (B) with respect to 100 parts by mass of the polyamide (A). The halogen-free flame retardant (B) is at least one selected from the group consisting of monophosphinates represented by the following general formula (1) and diphosphinates represented by the following general formula (2). The polyamide composition according to any one of claims 1-9 .

[In the above general formulas (1) and (2), R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a represents an arylalkyl group of numbers 7 to 20; R ⁵ represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 7 to 20 carbon atoms or an arylalkylene group having 7 to 20 carbon atoms. M represents calcium (ion), magnesium (ion), aluminum (ion) or zinc (ion). m is 2 or 3, n is 1 or 3, and x is 1 or 2. ] Polyamide composition according to any one of claims 1 to 10 , further comprising a filler (C). 12. The polyamide composition according to claim 11 , containing 0.1 parts by mass or more and 200 parts by mass or less of said filler (C) with respect to 100 parts by mass of said polyamide (A). A molded article made of the polyamide composition according to any one of claims 1 to 12 . 14. The molded article according to claim 13 , which is an electrical or electronic component. Containing a polyamide (A) having a dicarboxylic acid unit and a diamine unit and a halogen-free flame retardant (B),
More than 40 mol% and 100 mol% or less of the dicarboxylic acid units are naphthalene dicarboxylic acid units,
60 mol % to 100 mol % of the diamine units are branched aliphatic diamine units having 6 to 12 carbon atoms and linear aliphatic diamine units having 4 to 12 carbon atoms as optional structural units, and the branched The branched chain in the aliphatic diamine unit is a methyl group, and the ratio of the branched aliphatic diamine unit to the total 100 mol% of the branched aliphatic diamine unit and the linear aliphatic diamine unit is 60 mol % or more of a polyamide compositionsurface mount components.

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