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JP2015220493

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DESCRIPTION JP2015220493
To provide a speaker diaphragm having a small change in rigidity and a small change in sound
quality even under high temperature and high humidity. A crystalline semiaromatic polyamide
(A), a polyamide (B) other than (A) and a fibrous reinforcing material (C), wherein the mass ratio
of (A) to (C) is (A) A speaker diaphragm made of a polyamide resin composition satisfying: (B) =
100/0 to 60/40) and [(A) + (B)] / (C) = 10/10 to 100/80, And the vibrating plate wherein the
crystalline semi-aromatic polyamide (A) is polyamide 6T, polyamide 9T or polyamide 10T. 【
Selection chart】 None
Speaker diaphragm
[0001]
The present invention relates to a speaker diaphragm.
[0002]
In addition to high sound velocity, low density, and high Young's modulus, a diaphragm as a
speaker member is required to have a small change in internal loss (tan δ) in a use environment
as characteristics affecting sound.
[0003]
For example, Patent Document 1 discloses a speaker diaphragm made of a composite material in
which polyamide or polypropylene is reinforced with basic magnesium sulfate.
10-05-2019
1
Further, Patent Document 2 discloses a speaker diaphragm using ultra-high crystalline
polypropylene having a crystallinity of 70% or more.
However, when the speaker to which these diaphragms are applied is used in an environment
exposed to high temperature and high humidity such as in a car room, the former absorbs water
over time and the rigidity of the diaphragm is lowered, and the latter is high temperature In the
case of using any of the materials, the internal loss is largely changed.
[0004]
JP, 2004-274661, A JP, 11-75, 290 A
[0005]
An object of the present invention is to provide a speaker diaphragm in which a change in
rigidity and an internal loss is small and a change in sound quality is small even under high
temperature and high humidity.
[0006]
As a result of intensive studies to solve the above-mentioned problems, the present inventors
have used polyamides (B) other than crystalline semi-aromatic polyamides (A) and (A) and a
fibrous reinforcing material in a specific ratio, It has been found that the above object can be
achieved, and the present invention has been achieved.
[0007]
That is, the gist of the present invention is as follows.
(1) A crystalline semiaromatic polyamide (A), containing polyamide (B) other than (A) and a
fibrous reinforcing material (C), and the mass ratio of (A) to (C) is (A) / The speaker diaphragm
which consists of a polyamide resin composition which satisfies (B) = 100/0-60/40, and [(A) +
(B)] / (C) = 10/10-100/80.
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(2) The speaker diaphragm according to (1), wherein the crystalline semi-aromatic polyamide (A)
is polyamide 6T, polyamide 9T or polyamide 10T.
(3) The speaker diaphragm as described in (1) or (2) whose fibrous reinforcement (C) is a carbon
fiber.
[0008]
According to the present invention, it is possible to provide a speaker diaphragm in which
changes in rigidity and internal loss are small and changes in sound quality are small even under
high temperature and high humidity.
[0009]
Hereinafter, the speaker diaphragm of the present invention will be described in detail.
[0010]
The speaker diaphragm of the present invention is composed of a crystalline semi-aromatic
polyamide (A), a polyamide (B) other than (A) and a fibrous reinforcing material (C).
[0011]
The crystalline semiaromatic polyamide (A) used in the present invention is composed of an
aromatic dicarboxylic acid component and an aliphatic diamine component.
In addition, when the amount of heat of fusion measured by the measuring method mentioned
later using a differential scanning calorimeter is larger than 4 J / g, it is judged to be crystalline.
[0012]
Examples of the dicarboxylic acid component constituting the crystalline semi-aromatic
polyamide (A) include aromatic dicarboxylic acids such as terephthalic acid, phthalic acid,
isophthalic acid and naphthalene dicarboxylic acid. Among these, terephthalic acid is preferable.
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3
In the dicarboxylic acid component, the content of terephthalic acid is preferably 80 mol% or
more, and more preferably 90 mol% or more.
As the content of terephthalic acid in the dicarboxylic acid component is higher, the heat
resistance of (A) tends to be higher. The dicarboxylic acid component may be used alone or in
combination of two or more.
[0013]
In the present invention, dicarboxylic acids other than aromatic dicarboxylic acids may be used
as the dicarboxylic acid component as long as the effects of the present invention are not
impaired. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids such as oxalic
acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,
sebacic acid, undecanedioic acid, dodecanedioic acid, and the like And alicyclic dicarboxylic acids
such as cyclohexanedicarboxylic acid. The content of the other dicarboxylic acid in the
dicarboxylic acid component is preferably 5 mol% or less, and more preferably substantially free.
[0014]
As an aliphatic diamine component which comprises crystalline semi-aromatic polyamide (A), 1,
2- ethane diamine, 1, 3- propane diamine, 1, 4- butane diamine, 1, 5- pentane diamine, for
example , 6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl 1, 5- pentanediamine
and 2-methyl-1, 8- octanediamine are mentioned. Among them, 1,6-hexanediamine, 1,9nonanediamine and 1,10-decanediamine are preferable because of high versatility, and 1,9nonanediamine, 1,1 because heat resistance and mechanical strength are high. 10decanediamine is more preferred. Each of these may be used alone or in combination of two or
more.
[0015]
As the diamine component of the crystalline semiaromatic polyamide (A), other diamines other
than aliphatic diamines may be used as long as the effects of the present invention are not
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impaired. Other diamines include, for example, alicyclic diamines such as cyclohexane diamine,
and aromatic diamines such as xylylene diamine and benzene diamine. The content of the other
diamine in the diamine component is preferably 5 mol% or less, and more preferably
substantially free.
[0016]
For the crystalline semi-aromatic polyamide (A), a monocarboxylic acid may be used for the
purpose of adjusting the molecular weight. Examples of monocarboxylic acids include benzoic
acid, 4-ethylbenzoic acid, 4-hexylbenzoic acid, 4-laurylbenzoic acid, alkylbenzoic acids, aromatic
monocarboxylic acids such as 1-naphthoic acid and 2-naphthoic acid Aliphatic monocarboxylic
acids such as acetic acid, caprylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid,
palmitic acid, stearic acid and behenic acid, 4-ethylcyclohexanecarboxylic acid, 4hexylcyclohexanecarboxylic acid, 4 -Alicyclic monocarboxylic acids such as lauryl cyclohexane
carboxylic acid can be mentioned. Among them, it is preferable to use an aliphatic
monocarboxylic acid having a molecular weight of 140 or more because the fluidity at the time
of molding is improved. The content of monocarboxylic acid is preferably 5 mol% or less based
on the total number of moles of the raw material monomer.
[0017]
Moreover, as long as the effect of the present invention is not impaired, the crystalline semiaromatic polyamide (A) may be a lactam such as caprolactam or laurolactam, or an ωaminocarboxylic acid such as aminocaproic acid or 11-aminoundecanoic acid. It is also good. The
total content of lactams and ω-aminocarboxylic acid is preferably 5 mol% or less based on the
total number of moles of the raw material monomers, and it is more preferable that the total
content not be substantially contained.
[0018]
As the crystalline semi-aromatic polyamide (A), since it has high versatility, polyamide 6T
containing terephthalic acid and 1,6-hexanediamine as the main components, and polyamide
containing terephthalic acid and 1,9-nonanediamine as the main components 9T or polyamide
10T having terephthalic acid and 1,10-decanediamine as main components is preferred.
[0019]
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The crystalline semiaromatic polyamide (A) preferably has a melting point of 300 ° C. or more,
more preferably 320 ° C. or more.
[0020]
The crystalline semiaromatic polyamide (A) used in the present invention preferably has a
relative viscosity of 1.8 or more when measured at a concentration of 1 g / dL in 96% sulfuric
acid at 25 ° C., 1.8 It is more preferable that it is -3.0, and it is further more preferable that it is
1.9-2.8.
[0021]
The weight average molecular weight of the crystalline semiaromatic polyamide (A) is preferably
from 15,000 to 50,000, more preferably from 20,000 to 50,000, and still more preferably from
20,000 to 50,000.
[0022]
The crystalline semi-aromatic polyamide (A) can be produced using a conventionally known
method of heat polymerization or solution polymerization.
Among them, the heat polymerization method is preferably used from the industrially
advantageous point.
[0023]
In the production of the crystalline semiaromatic polyamide (A), a polymerization catalyst may be
used to enhance the efficiency of the polymerization.
The polymerization catalyst includes, for example, phosphoric acid, phosphorous acid,
hypophosphorous acid or salts thereof.
[0024]
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The polyamide (B) used in the present invention is not particularly limited as long as it is a
polyamide other than the crystalline semiaromatic polyamide (A).
As polyamides other than (A), for example, polycaproamide (polyamide 6), polyhexamethylene
adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), polyhexamethylene
sebacamide (polyamide 610) ), Polyhexamethylene dodecamide (polyamide 612),
polyundecamethylene adipamide (polyamide 116), polybis (4-aminocyclohexyl)
methandodecamide (polyamide PACM12), polybis (3-methyl-4aminocyclohexyl) methane
Dodecamide (polyamide dimethyl PACM 12), polyundecamide (polyamide 11), poly dodecamide
(polyamide 12), polytrimethylhexamethylene terephthalamide (polyamide TMDT),
polyhexamethylene isophthalic acid (Polyamide 6I), polymetaxylylene adipamide (polyamide
MXD 6), and copolymers thereof, crystalline polyamides such as mixtures, isophthalic acid /
terephthalic acid / hexamethylene diamine / bis (3-methyl-4-amino) Polycondensate of
cyclohexyl) methane, Polycondensate of terephthalic acid / 2,2,4trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine, Isophthalic acid / bis
(3-methyl-4-aminocyclohexyl ) Methane / ω-laurolactam polycondensate, isophthalic acid /
terephthalic acid / hexamethylene diamine polycondensate, isophthalic acid / 2,2,4trimethylhexamethylene diamine / 2,4,4-trimethylhexamethylene diamine Polycondensate,
isophthalic acid / terephthalic acid / 2,2 Polycondensate of 4, 4-trimethylhexamethylenediamine
/ 2,4, 4-trimethylhexamethylenediamine, isophthalic acid / bis (3-methyl-4-aminocyclohexyl)
methane / ω-laurolactam polycondensate, isophthalic acid / Poly (terephthalic acid /
hexamethylenediamine / bis (3-methyl-4-aminocyclohexyl) methane polycondensate and
terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine
Amorphous polyamides such as mixtures of polycondensates are mentioned.
The benzene ring of the aromatic component which comprises these may be substituted by the
alkyl group or the halogen atom. Among (B), polyamide 6, polyamide 66, polycondensate of
isophthalic acid / terephthalic acid / hexamethylene diamine, weight of isophthalic acid /
terephthalic acid / hexamethylene diamine / bis (3-methyl-4-aminocyclohexyl) methane
Preferred are condensation products and polycondensates of terephthalic acid / 2,2,4trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylenediamine.
[0025]
The blending ratio of the crystalline semiaromatic polyamide (A) and the polyamide (B) other
than (A) may be in the range of (A) / (B) = 100/0 to 60/40 (mass ratio) It is necessary, and it is
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7
preferable to set it as 90/10-70/30 (mass ratio). By blending (B), the flowability at the time of
molding can be improved, and the appearance of the molded body can be improved. If the
content of (B) exceeds 40% by mass with respect to 100% by mass of (A) and (B) in total, the
rigidity retention rate is lowered, and the change rate of internal loss is increased, which is not
preferable.
[0026]
The fibrous reinforcing material (C) used in the present invention is not particularly limited. For
example, carbon fiber, glass fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester
fiber, acrylic fiber, aramid fiber, polybenzoxazole fiber , Polytetrafluoroethylene fiber, kenaf fiber,
bamboo fiber, hemp fiber, bagasse fiber, high strength polyethylene fiber, alumina fiber, silicon
carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber,
basalt fiber , Sepiolite, palygorskite. Two or more of the above may be used in combination.
Among them, carbon fiber and aramid fiber are preferable in view of low specific gravity.
[0027]
The content of the fibrous reinforcing material needs to be 10 to 80 parts by mass with respect
to 100 parts by mass in total of the semiaromatic polyamide (A) and (B), and may be 15 to 60
parts by mass Preferably, it is more preferably 20 to 50 parts by mass. If the content of the
fibrous reinforcing material is less than 10 parts by mass, the rigidity is not sufficient. On the
other hand, when the content of the fibrous reinforcing material exceeds 80 parts by mass,
strand breakage frequently occurs during melt-kneading to be described later, which makes it
difficult to obtain resin composition pellets.
[0028]
Additives may be further added to the polyamide resin composition used in the present
invention. Examples of additives include plate-like reinforcing materials, talc, swelling clay
minerals, silica, alumina, fillers such as glass beads, antioxidants, copper compounds, antistatic
agents, flame retardants, and flame retardant aids. Be
[0029]
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The polyamide resin composition used in the present invention comprises a semi-aromatic
polyamide (A), a polyamide (B) other than (A), a fibrous reinforcing material (C), other additives,
etc. Manufactured by Examples of the melt-kneading method include a method using a batch
type kneader such as Brabender, a Banbury mixer, a Henschel mixer, a helical rotor, a roll, a
single screw extruder, a twin screw extruder, and the like. The melt-kneading temperature is not
particularly limited as long as it is a temperature at which the semiaromatic polyamide (A) does
not melt and decompose, but (the melting point of the semiaromatic polyamide-20 ° C) or more,
the melting point of the semiaromatic polyamide + 40 ° C It is preferable to set it as the
following.
[0030]
The polyamide melt mixture is melt-kneaded and extruded in the form of strands in a strand, hotcut and underwater-cut to form pellets, extruded and cut in sheets, or extruded and crushed in
blocks to form powders. can do.
[0031]
The speaker diaphragm of the present invention can be manufactured by a known method.
For example, the polyamide resin composition can be manufactured by filling the inside of a
cavity of a mold constituted by a movable mold and a fixed mold, injection molding, and opening
the mold after a predetermined time has elapsed. . The shape of the speaker diaphragm is not
particularly limited, and examples thereof include a cone shape, a dome shape, and a flat shape.
[0032]
At the time of molding the speaker diaphragm, it is preferable to use a polyamide resin
composition pellet which has been sufficiently dried. If the amount of water contained is large,
the resin may foam in the cylinder during molding, which may make it difficult to obtain an
optimum speaker diaphragm. The moisture content of the polyamide resin composition pellet
used for injection molding is preferably less than 0.3 parts by mass and more preferably less
than 0.1 parts by mass with respect to 100 parts by mass of the polyamide resin composition.
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[0033]
Hereinafter, the present invention will be specifically described by way of examples, but the
present invention is not limited thereto.
[0034]
1.
Measurement method, evaluation method
[0035]
(1) Melting point and heat of fusion Using a differential scanning calorimeter DSC-7
manufactured by PerkinElmer, after raising the temperature to 350 ° C at a heating rate of 20
° C / min, hold at 350 ° C for 5 minutes to lower the temperature The temperature was
lowered to 25 ° C. at a rate of 20 ° C./min. After holding for 5 minutes at 25 ° C., the
temperature is raised again at a heating rate of 20 ° C./min, the top of the endothermic peak is
taken as the melting point, and the peak area is taken as the heat of fusion.
[0036]
(2) Relative viscosity 96% by mass Sulfuric acid was used as a solvent and measured at a
concentration of 1 g / dL at 25 ° C.
[0037]
(3) Weight average molecular weight GPC analysis is performed using a sample solution adjusted
under the following conditions using a gel permeation chromatography apparatus manufactured
by Tosoh Corporation, and then a calibration curve prepared using polymethyl methacrylate
(manufactured by Polymer Laboratories) as a standard sample is used. The weight average
molecular weight was determined using this.
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<Sample preparation> 2 mg of 10 mM sodium trifluoroacetate-containing hexafluoroisopropanol
was added to 5 mg of polyamide and dissolved, followed by filtration through a disc filter.
<Conditions> Detector: Differential refractive index detector RI-8010 (manufactured by Tosoh
Corporation) Eluent: 10 mM sodium trifluoroacetate-containing hexafluoroisopropanol Flow rate:
0.4 mL / min Temperature: 40 ° C.
[0038]
(4) The flexural modulus under standard conditions After sufficiently drying the polyamide resin
composition, it was injection molded using an injection molding machine (EC-100 manufactured
by Toshiba Corporation) to prepare a test piece (dumbbell piece) . The cylinder temperatures of
Examples 1 to 13 and Comparative Examples 3 and 4 are (melting point of semiaromatic
polyamide + 10 ° C), Comparative Example 1 is 260 ° C, Comparative Example 2 is 280 ° C,
and mold temperature is 130 °. C, the injection speed was 150 mm / sec, and the holding
pressure was 60 MPa. The obtained test piece was measured in accordance with ISO 178 under a
23 ° C. environment. For practical use, the flexural modulus under standard conditions is
preferably 5 GPa or more.
[0039]
(5) Test pieces obtained under the standard conditions of flexural modulus after moisture
absorption treatment (4) are subjected to moisture absorption treatment at 65 ° C. × 60% RH
for 500 hours, and then in accordance with ISO 178 at 23 ° C. environment It was measured.
The retention rate (%) with respect to the value of standard conditions was determined using the
obtained value. The retention rate is preferably 80% or more.
[0040]
(6) Specimens obtained under the standard conditions of flexural modulus (4) under 80 ° C.
environment were measured according to ISO 178 under 80 ° C. environment. The retention
rate (%) with respect to the value of standard conditions was determined using the obtained
value. The retention rate is preferably 80% or more.
[0041]
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(7) Change rate of internal loss After sufficiently drying the polyamide resin composition,
injection molding is performed using an injection molding machine (EC-100 manufactured by
Toshiba Corporation), and test pieces (strip shape, width 12.7 mm × length 127 mm x thickness
0.8 mm) were produced. The cylinder temperatures of Examples 1 to 13 and Comparative
Examples 3 and 4 are (melting point of semiaromatic polyamide + 10 ° C), Comparative
Example 1 is 260 ° C, Comparative Example 2 is 280 ° C, and mold temperature is 130 °. C,
the injection speed was 150 mm / sec, and the holding pressure was 60 MPa. The internal loss of
the obtained test piece was measured in a tensile mode, vibration frequency 1 Hz, strain 0.1%,
heating rate 2 ° C./min under an environment of 23 ° C. using a rheometric viscoelasticity
analyzer RSAII. It measured on condition of. Next, the test piece was subjected to moisture
absorption treatment at 65 ° C. × 60% RH for 500 hours, and then the internal loss was
measured under the same conditions. The rate of change (%) was determined from the following
equation using measured values of internal loss before and after the moisture absorption
treatment. Rate of change = (internal loss after moisture absorption treatment−internal loss
before moisture absorption treatment) / (internal loss before moisture absorption treatment) The
rate of change is preferably 2% or less. In addition, the internal loss of the test piece in an 80 °
C. environment was measured, and similarly, the rate of change (%) was determined from the
following equation. Rate of change = (internal loss under 80 ° C. environment = internal loss
under 23 ° C. environment) / (internal loss under 23 ° C. environment) The rate of change is
preferably 2% or less.
[0042]
2. Raw material (1) Dicarboxylic acid component · TPA: Terephthalic acid
[0043]
(2) Diamine component · NDA: 1, 9-nonane diamine · DDA: 1, 10-decane diamine
[0044]
(3) End blocking agent · STA: stearic acid
[0045]
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(4) 4.70 kg of powdered TPA as a semi-aromatic polyamide P-1 aromatic dicarboxylic acid
component, 0.33 kg of STA as a monocarboxylic acid component, and 20 g of sodium
hypophosphite monohydrate as a polymerization catalyst The reactor was placed in a ribbon
blender type reactor and heated to 170 ° C. with stirring at a rotation speed of 30 rpm under a
nitrogen blanket.
Thereafter, while the temperature is maintained at 170 ° C. and the rotation speed is
maintained at 30 rpm, 4.97 kg of DDA heated to 100 ° C. as an aliphatic diamine component
using a liquid injection apparatus over 2.5 hours The reaction product was obtained by
continuous addition (continuous liquid injection method).
The molar ratio of the raw material monomers is TPA: DDA: STA = 48.5: 49.5: 2.0 (functional
group equivalent ratio is TPA: DDA: STA = 49.0: 50.0: 1.0). Met. Subsequently, the obtained
reaction product was polymerized by heating in the same reactor under a nitrogen stream at 250
° C. and a rotation number of 30 rpm for 8 hours to prepare a semi-aromatic polyamide
powder. Thereafter, the obtained semi-aromatic polyamide powder is made into strands using a
twin-screw kneader, and the strands are passed through a water bath to cool and solidify, which
is cut with a pelletizer to obtain semi-aromatic polyamide (P-1) I got
[0046]
P-2 to P-4 Semi-aromatic polyamide (P-2) to (P-4) in the same manner as the semi-aromatic
polyamide (P-1) except that the monomer used is changed as shown in Table 1 Got).
[0047]
The resin composition of the obtained semiaromatic polyamide and the characteristic value
thereof are shown in Table 1.
[0048]
[0049]
Semi-aromatic polyamide (P-5) Polyamide 6T manufactured by Mitsui Chemicals, Inc. Arlen A
3000, melting point 320 ° C., heat of fusion 38 J / g
[0050]
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(5) Polyamides other than crystalline semi-aromatic polyamides: PA6: polyamide 6, A1030 BRL
manufactured by Unitika, relative viscosity 2.51, heat of fusion 71 J / g PA 66: polyamide 66, 50
BWFS manufactured by Ascend, relative viscosity 2.75 Heat of fusion 84 J / g Amorphous PA:
Polycondensate of isophthalic acid / terephthalic acid / hexamethylene diamine, DSM X21, glass
transition temperature 125 ° C., relative viscosity 2.0, heat of fusion 0.4 J / g
[0051]
(6) Fibrous Reinforcement · E-1: Carbon fiber, HTA-C6-NR manufactured by Toho Tenax, average
fiber diameter 7 μm, average fiber length 6 mm · E-2: Aramid fiber, Technora T322UR3-12
manufactured by Teijin Limited Average fiber length 3mm
[0052]
Example 1 100 parts by mass of a semi-aromatic polyamide (P-1) is supplied to the main supply
port of a twin screw extruder (TEM 37BS manufactured by Toshiba Machine Co., Ltd.) with a
screw diameter of 37 mm and L / D 40, 30 parts by mass of fibers were supplied and meltkneaded.
320 ° C. to 340 ° C., screw rotation speed 250 rpm, and discharge amount 35 kg / hour.
Then, after taking it in a strand form, it was cooled and solidified by passing through a water
bath, and it was cut with a pelletizer to obtain polyamide resin composition pellets.
[0053]
Examples 2 to 13 and Comparative Examples 1 to 4 Polyamide resin composition pellets were
obtained in the same manner as Example 1, except that the composition of the resin composition
was changed as shown in Table 2.
However, the melt-kneading temperature of Comparative Example 1 was 250 ° C. to 260 ° C.,
and the melt-kneading temperature of Comparative Example 2 was 270 ° C. to 290 ° C.
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[0054]
Comparative Example 5 A semiaromatic polyamide resin composition pellet was obtained in the
same manner as Comparative Example 3 except that the content of the fibrous reinforcing
material was 90 parts by mass with respect to 100 parts by mass of the semiaromatic polyamide.
However, the strands were cut and it was not possible to obtain polyamide resin composition
pellets.
[0055]
The compositions of the polyamide resin compositions obtained in the examples and comparative
examples and their characteristic values are shown in Table 2.
[0056]
[0057]
In Examples 1 to 13, the retention of the flexural modulus was high and the change rate of the
internal loss was small under any condition after the moisture absorption treatment and under
the environment of 80 ° C.
Therefore, it turns out that it is suitable as a resin composition for speaker diaphragms.
[0058]
In Comparative Examples 1 and 2, the crystalline semiaromatic polyamide was not used, so the
retention of flexural modulus was low.
In addition, the rate of change in internal loss was also large.
Comparative Example 3 had a low flexural modulus under standard conditions because the
content of the fibrous reinforcement was less than the range specified in the present invention.
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In Comparative Example 4, since the content of the crystalline semiaromatic polyamide with
respect to the total of the crystalline semiaromatic polyamide and the polyamide other than the
polyamide is smaller than the range specified in the present invention, the retention of flexural
modulus is low. The
In addition, the rate of change in internal loss was also large.
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