JP6155661B2 - Semi-aromatic polyamide resin composition - Google Patents

Description

  The present invention relates to a semi-aromatic polyamide resin composition. Specifically, it has low water absorption, physical properties such as mechanical strength and toughness, and excellent thin-wall moldability, as well as excellent surface appearance of a molded product, such as gas and water. The present invention relates to a semi-aromatic polyamide resin composition that can suppress the occurrence of poor appearance such as sink marks and flow marks even when used in fluid-assisted molding.

Conventionally, aliphatic polyamide resins such as polyamide 6 and polyamide 66 are widely used in automobile parts, electrical parts, electronic parts, household goods and the like because of their excellent mechanical properties, impact resistance, and chemical resistance. However, these aliphatic polyamide resins have high heat resistance, dimensional stability, mechanical properties, chemical resistance, etc. in applications where there are problems such as insufficient heat resistance and poor dimensional stability due to water absorption. Semi-aromatic polyamide resins such as 6T and 9T copolymer polyamides copolymerized with excellent aromatic components have been used (for example, Patent Documents 1 to 3).
However, these semi-aromatic polyamide resins generally have low toughness and impact resistance, a large decrease in flexural modulus due to water absorption, and sufficient appearance and crystallinity unless molded at extremely high mold temperatures. However, as a result, there is a problem that the generation of burrs cannot be suppressed.

  Accordingly, the present inventors have excellent physical properties such as mechanical strength and toughness, low water absorption, small change in water absorption dimension, little change in flexural modulus due to water absorption, and high flowability and thin molding capable of thin wall molding. Proposed a composition mainly composed of a mixture of a specific semi-aromatic polyamide resin and an amorphous polyamide resin (Patent Document 4), but there is room for improvement in terms of appearance such as gloss and sink marks of the molded product. there were.

JP-A-3-281532 JP 2000-86759 A Japanese Patent No. 3155619 JP 2012-136620 A

  Low water absorption, excellent mechanical properties such as mechanical strength and toughness, and excellent thin-wall moldability, as well as excellent surface appearance of molded products, and poor appearance such as sink marks and flow marks even when used in fluid-assisted molding of gas and water. It is providing the semi-aromatic polyamide resin composition which can suppress generation | occurrence | production etc.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies on the crystallization delay behavior of the semi-aromatic polyamide resin blended with the amorphous polyamide resin.

That is, the present invention has the following configuration.
(1) It contains 2 to 40 parts by mass of amorphous polyamide (B) with respect to 100 parts by mass of semi-aromatic polyamide (A), and semi-aromatic polyamide (A) and amorphous polyamide (B) A semi-aromatic polyamide resin composition characterized by satisfying the following requirements (a) and (b):
(A) An amide unit (b1) in which the amorphous polyamide (B) comprises a diamine component having a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms ) And an amide unit (b2) other than the amide unit (b1).
(B) The difference in SP value between the semi-aromatic polyamide (A) and the amorphous polyamide (B) is -1.0 to 1.0.
(2) A diamine component having a dicyclohexylmethane skeleton in which an amide unit (b2) other than the amide unit (b1) has an alkyl group having 1 to 5 carbon atoms as a substituent and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms An amide unit other than (b1), an amide unit comprising a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an isophthalic acid component, and an aminocarboxylic acid or lactam having 8 to 18 carbon atoms The semi-aromatic polyamide resin composition according to (1), which is at least one selected from amide units consisting of:
(3) The semiaromatic polyamide (A) is a copolymerized polyamide comprising (a) 50 to 98 mol% of decanterephthalamide units and (b) 50 to 2 mol% of undecanamide units or / and dodecanamide units ( The semi-aromatic polyamide resin composition as described in 1) or (2).
(4) In the resin composition in which the amorphous polyamide (B) is 20% by mass of the amorphous polyamide (B) and 80% by mass of the semi-aromatic polyamide (A), the semi-aromatic polyamide (A) The semi-aromatic polyamide resin composition according to any one of (1) to (3), which lowers the temperature-falling crystallization temperature (Tc ₂ ) of 8 ° C. or more.
(5) When the melt viscosity of the amorphous polyamide (B) is (η _B ) and the melt viscosity of the semi-aromatic polyamide (A) is (η _A ) at 265 ° C. and a shear rate of 500 sec ⁻¹ . The semi-aromatic polyamide resin composition according to any one of (1) to (4), wherein [1- (η _B ) / (η _A )] is −0.3 to 0.3.

In the semi-aromatic polyamide resin composition of the present invention, the crystallization of the semi-aromatic polyamide resin is delayed by the action of a specific amorphous polyamide resin. It is possible to mold a molded product having excellent surface gloss.
Further, since the effect of delaying crystallization is great, it is suitable as a molding material for fluid assist molding such as gas and water.

The present invention will be specifically described below.
The semi-aromatic polyamide (A) in the present invention is a semi-aromatic polyamide resin having an acid amide bond (—CONH—) in the molecule and an aromatic ring (benzene ring). The semi-aromatic polyamide (A) is preferably crystalline and has a crystalline melting point.
Specifically preferred semi-aromatic polyamide (A) is (a) 50 to 98 mol% of a structural unit obtained from an equivalent molar salt of decanediamine and terephthalic acid, and (b) 11-aminoundecanoic acid or 12 -It is a polyamide resin which consists of 50-2 mol% of structural units obtained from 1 type or a mixture among aminododecanoic acid, undecane lactam, and lauryl lactam. The semi-aromatic polyamide in the present invention includes (c) a structural unit obtained from an equivalent molar salt of a diamine other than the structural unit of (a) and a dicarboxylic acid, or an aminocarboxylic acid other than the structural unit of (b) or The structural unit obtained from lactam can be contained up to 30 mol%.
Hereinafter, a decanterephthalamide unit is abbreviated as 10T, an undecanamide unit is 11, and a dodecanamide unit is abbreviated as 12, for example, a copolymer composed of a decanterephthalamide unit and an undecanamide unit may be represented as 10T / 11.

  The relative viscosity measured by a 96% sulfuric acid solution of the semi-aromatic polyamide (A) in the present invention (polyamide resin concentration 1 g / dl, 25 ° C.) is preferably in the range of 1.6 to 2.8. A particularly preferred relative viscosity is in the range of 1.8 to 2.6. If it is less than 1.6, it is not preferable because the toughness is lowered, and if it exceeds 2.8, the fluidity is lowered.

  The semi-aromatic polyamide (A) in the present invention is obtained from an equimolar molar salt of (c) a diamine other than the structural unit of (a) and a dicarboxylic acid, in addition to the components (a) and (b). A unit or a structural unit obtained from an aminocarboxylic acid or lactam other than the structural unit of (b) may be copolymerized at a maximum of 30 mol%. As the component (c), the copolymer polyamide has a role of imparting other characteristics that cannot be obtained by 10T polyamide, 11 polyamide, and 12 polyamide, and further improving characteristics obtained by 10T polyamide, 11 polyamide, and 12 polyamide. It is what you have.

  Specific examples of the copolymer component used in (c) include the following copolymer components. As the amine component, 1,2-ethylenediamine, 1,3-trimethylenediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 2-methyl-1,5-pentamethylenediamine, 1,6 -Hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 2-methyl-1,8-octamethylenediamine, 1,10-decamethylenediamine, 1 , 11-Undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,16-hexadecamethylenediamine, 1,18-octadecamethylenediamine, 2,2,4 (or 2,4,4) -aliphatic diamines such as trimethylhexamethylenediamine, piperazine Cyclohexanediamine, bis (3-methyl-4-aminohexyl) methane, bis- (4,4′-aminocyclohexyl) methane, cycloaliphatic diamine such as isophoronediamine, metaxylylenediamine, paraxylylenediamine, para Examples thereof include aromatic diamines such as phenylenediamine and metaphenylenediamine, and hydrogenated products thereof. As the acid component of the polyamide, the following polyvalent carboxylic acids or acid anhydrides can be used. Examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, and 2,2′-diphenyl. Aromatic dicarboxylic acids such as dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sulfonic acid sodium isophthalic acid, 5-hydroxyisophthalic acid, fumaric acid, maleic acid, succinic acid, itaconic acid, adipic acid, azelaic acid, Sebacic acid, 1,11-undecanedioic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohex Njikarubon acid, and an aliphatic or alicyclic dicarboxylic acids such as dimer acid. Further, lactams such as ε-caprolactam and aminocarboxylic acids having a structure in which they are ring-opened can be mentioned.

  Specific examples of the component (c) include polycaproamide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polyundecamethylene adipamide (polyamide 116). ), Polymetaxylylene adipamide (polyamide MXD6), polyparaxylylene adipamide (polyamide PXD6), polytetramethylene sebamide (polyamide 410), polyhexamethylene sebamide (polyamide 610), polydecamethylene Adipamide (polyamide 106), polydecamethylene sebacamide (polyamide 1010), polyhexamethylene dodecamide (polyamide 612), polydecamethylene dodecamide (polyamide 1012), polyhexamethylene isophthalamide (polyamide 6I), Ritetramethylene terephthalamide (polyamide 4T), polypentamethylene terephthalamide (polyamide 5T), poly-2-methylpentamethylene terephthalamide (polyamide M-5T), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene hexa Hydroterephthalamide (Polyamide 6T (H)) Polynonamethylene terephthalamide (Polyamide 9T), Polyundecamethylene terephthalamide (Polyamide 11T), Polydodecamethylene terephthalamide (Polyamide 12T), Polybis (3-methyl-4-amino) Hexyl) methane terephthalamide (polyamide PACMT), polybis (3-methyl-4-aminohexyl) methane isophthalamide (polyamide PACMI), polybis (3-methyl) 4-aminohexyl) methane dodecamide (polyamide PACM12), and the like polybis (3-methyl-4-amino-hexyl) methane tetradecanoyl bromide (polyamide PACM14).

Among the structural units, examples of a preferable component (c) include polydodecamethylene terephthalamide (polyamide 12T) and polydecamethylene sebacamide (polyamide 1010) for improving processability, low water absorption, and impact resistance. And polydecamethylene dodecamide (polyamide 1012). The blending ratio of the component (c) in the copolymerized polyamide is preferably up to 30 mol%, more preferably 5 to 20 mol%. When the proportion of the component (c) is less than the above lower limit, the effect of the component (c) may not be sufficiently exhibited. When the proportion exceeds the above upper limit, the amount of the essential component (a) or component (b) is small. Therefore, the originally intended effect of the copolymerized polyamide of the present invention may not be sufficiently exhibited, which is not preferable.
The semi-aromatic polyamide (A) in the present invention is not greatly different in properties, but it is preferable to use plant-derived raw materials in order to achieve a low carbon society and environmental harmony. Specifically, it is preferable to use a castor oil-derived raw material that does not compete with food, decanediamine in component (a) in the present invention, aminoundecanoic acid in component (b), and sebacic acid in component (c) It is preferable to use plant-derived materials. Preferable resin compositions of the present invention include polyamide 10T / 11 and polyamide 10T / 1010/11, which use these plant raw materials and exhibit an extremely high plant-derived raw material ratio.

In the semi-aromatic polyamide resin composition of the present invention, an amorphous polyamide (B) is blended in order to improve the surface appearance of the molded product and to impart low sink characteristics.
The amorphous polyamide (B) comprises (i) an amide unit (b1) comprising a diamine component having a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms. ) And an amide unit (b2) other than the amide unit (b1), and (b) a difference in SP value between the semiaromatic polyamide (A) and the amorphous polyamide (B) [ (SP value of semi-aromatic polyamide (A))-(SP value with amorphous polyamide (B))] is -1.0 to 1.0.
In addition, SP value calculated | required from the formula of Fedors shown below is used for SP value.
δi = [Ev / V] ^1/2 = [Δei / Δvi] ^1/2
δi: SP value Ev: Evaporation energy V: Molar volume Δei: Evaporation energy of i component atom or atomic group Δvi: Molar volume of i component atom or atomic group Amorphous in the present invention is in accordance with JIS K7121 When the DSC measurement is performed at a heating rate of 20 ° C./min, no clear melting point peak is shown.

In the amorphous polyamide (B), a preferred example of a diamine having a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms constituting the amide unit (b1) as a substituent is bis (3-methyl-4- Amino-cyclohexyl) methane (may be abbreviated as MACM), 2,2-bis (4-amino-cyclohexyl) propane, and the like. Preferred examples of the aliphatic dicarboxylic acid having 8 to 18 carbon atoms include azelain. And acid, sebacic acid, undecanedioic acid, dodecanedioic acid (sometimes abbreviated as 12), tridecanedioic acid, tetradecanedioic acid (sometimes abbreviated as 14), and the like.
The alkyl group having 1 to 5 carbon atoms may be substituted with either a cyclohexane ring or a methane part, but is preferably substituted with a cyclohexane ring.

The amide unit (b2) other than the amide unit (b1) comprises a diamine component having a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms ( an amide unit other than b1), an amide unit comprising a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an isophthalic acid component, and an amide comprising an aminocarboxylic acid or lactam having 8 to 18 carbon atoms It is preferably at least one selected from units.
Among the aminocarboxylic acids or lactams having 8 to 18 carbon atoms, 11-aminoundecanoic acid and 12-aminododecanoic acid are preferable.

Although the molecular weight of the amorphous polyamide (B) used for this invention is not specifically limited, It is preferable that a number average molecular weight is the range of 3000-40000. When the number average molecular weight is less than 3000, the mechanical strength is lowered. On the other hand, when the number average molecular weight is more than 40000, the molecular weight becomes too high and the moldability is deteriorated.
Another measure for expressing the molecular weight is melt viscosity. The melt viscosity of the amorphous polyamide (B) at 265 ° C. and a shear rate of 500 sec ^{−1 with} a capillary rheometer is preferably in the range of 80 to 250 Pa · s. A range of 100 to 220 Pa · s is more preferable, and a range of 120 to 200 Pa · s is more preferable.

  Moreover, the compounding quantity of an amorphous polyamide (B) is 2-40 mass parts with respect to 100 mass parts of semi-aromatic polyamide (A). If it is less than 2 parts by mass, the effect of addition is small, and if it exceeds 40 parts by mass, the characteristics of the semi-aromatic polyamide resin tend to be difficult to be exhibited. The compounding amount of the amorphous polyamide (B) is preferably 5 to 35 parts by mass, more preferably 10 to 30 parts by mass, and further preferably 15 to 25 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide (A). preferable.

The amorphous polyamide (B) used in the present invention is a semi-aromatic polyamide (A) in a resin composition having a blending ratio of 20% by mass of amorphous polyamide (B) and 80% by mass of semi-aromatic polyamide (A). It is preferable that the temperature-falling crystallization temperature (Tc ₂ ) is lowered by 8 ° C. or more from the viewpoint of improving the surface appearance of the molded product. In the resin composition of the present invention, the amount of the amorphous polyamide (B) is reduced by 6 ° C. or more from the temperature lowering crystallization temperature (Tc ₂ ) when the amorphous polyamide resin (B) is not blended. It is preferable that

The melt viscosity of the amorphous polyamide (B) is (η _B ) and the melt viscosity of the semiaromatic polyamide (A) is (η _A ) at a melt viscosity at 265 ° C. and a shear rate of 500 sec ⁻¹ using a capillary rheometer. At this time, [1- (η _B ) / (η _A )] is preferably −0.3 to 0.3 in view of easy compatibilization.

A reinforcing material can be blended in the semi-aromatic polyamide resin composition of the present invention. The compounding amount of the reinforcing material is preferably 1 to 150 parts by mass and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide (A).
In addition to the above, the semi-aromatic polyamide resin composition of the present invention includes a light or heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, a lubricant, a crystal within a known range as necessary. Add nucleating agent, mold release agent, antistatic agent, halogen flame retardant and antimony trioxide combination, various phosphoric flame retardant, melamine flame retardant, inorganic pigment, organic pigment, dye, or other polymers I can do it. The total amount of these blends is preferably 1 to 70 parts by mass and more preferably 3 to 50 parts by mass with respect to 100 parts by mass of the semi-aromatic polyamide (A).

As a production method for producing the semi-aromatic polyamide resin composition of the present invention, at least the components (A) and (B) described above and other blends are blended in any blending sequence in the blending composition. Mix with a tumbler or Henschel mixer and melt knead. The melt kneading method can be any method known to those skilled in the art, and a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, a roll, etc. can be used, among which a twin-screw extruder is used. It is preferable to do.
Moreover, it is preferable to introduce glass fibers or the like that are easily damaged during extrusion processing from the side port of the twin-screw extruder to prevent the glass fibers from being damaged, but it is not particularly limited. The silane coupling agent may be added at the same time as the raw material component, but it is preferable that the silane coupling agent is added to glass fiber or the like in advance.
In addition, in order to remove volatile components and decomposed low-molecular components during processing, and to increase the reactivity of the modified resin and reinforcing material with the polyamide resin, the side opening of the glass fiber input portion and the tip of the extruder It is desirable to perform suction with a vacuum pump between the die head.

EXAMPLES Next, although this invention is demonstrated concretely using an Example and a comparative example, this invention is not limited to these.
(1) Raw materials used in Examples and Comparative Examples [semi-aromatic polyamide (A): synthesis of polyamide 10T / 11]
Decamethylenediamine 8.26 kg, terephthalic acid 7.97 kg, 11-aminoundecanoic acid 6.43 kg, sodium diphosphite 9 g, terminal adjuster 40 g acetic acid and 17.52 kg ion-exchanged water in a 50 liter autoclave The pressure was charged with N ₂ from normal pressure to 0.05 MPa, the pressure was released, and the pressure was returned to normal pressure. This operation was performed 3 times, N ₂ substitution was performed, and then uniform dissolution was performed at 135 ° C. and 0.3 MPa with stirring. Thereafter, the solution was continuously supplied by a liquid feed pump, heated to 240 ° C. with a heating pipe, and heated for 1 hour. Thereafter, the reaction mixture was supplied to a pressure reaction can, heated to 290 ° C., and a part of water was distilled off so as to maintain the internal pressure of the can at 3 MPa to obtain a low-order condensate. Thereafter, this low-order condensate is directly supplied to a twin-screw extruder (screw diameter 37 mm, L / D = 60) while maintaining a molten state, and the resin temperature is 330 ° C. while water is being removed from three vents. Polycondensation proceeded under melting to obtain a copolymerized polyamide. The obtained copolymer polyamide had a composition of 10T / 11 = 60/40 (molar ratio), a melting point of 250 ° C., a relative viscosity of 2.6, and a temperature-falling crystallization temperature (Tc ₂ ) of 223 ° C. The SP value is 11.55 (calculated value), and the melt viscosity by a capillary rheometer (265 ° C., 500 sec ⁻¹ ) is 155 Pa · s.

[Amorphous polyamide (B)]
MACM · 12 / MACM · I: Co-form consisting of bis (3-methyl-4-amino-cyclohexyl) methane, 1,12-dodecanedioic acid / bis (3-methyl-4-amino-cyclohexyl) methane and isophthalic acid Polymerized polyamide EMS TR-55, Tg 155 ° C., SP value 10.64, melt viscosity 192 Pa · s (265 ° C., 500 sec ⁻¹ )
MACM · 10/11: Copolymer polyamide comprising bis (3-methyl-4-amino-cyclohexyl) methane and sebacic acid / 11-aminoundecanoic acid G-830 manufactured by Arkema, Tg 130 ° C., SP value: 11.92 , Melt viscosity 126 Pa · s (265 ° C., 500 sec ⁻¹ )
MACM · 14: Copolymer polyamide made of bis (3-methyl-4-amino-cyclohexyl) methane and 1,14-tetradecanedioic acid G350 manufactured by Arkema, Tg 146 ° C., SP value: 10.41, melt viscosity 127 Pa · s (265 ° C., 500 sec ⁻¹ )
● 6T6I: 6T / 6I = 33/67 mol%
EMS Grivory G21, Tg 125 ° C., SP value: 12.90, melt viscosity 128 Pa · s (265 ° C., 500 sec ⁻¹ )

[Fibrous reinforcement]
Glass fiber: Nippon Electric Glass Co., Ltd. T-275H

(2) Measuring method of characteristic and physical property values (a) Melting point, Tc ₂ :
A DSC measuring device (EXSTAR6000, manufactured by Seiko Instruments Inc.) was used. It is a numerical value measured by raising the temperature to 300 ° C. at a rate of temperature increase of 20 ° C./min under a nitrogen stream, holding the temperature for 5 minutes, and then decreasing the temperature to 50 ° C. at a rate of 10 ° C./min. . The melting point was the peak top of the endothermic peak when the temperature was raised. Similarly Tc ₂ was a peak top of the exothermic peak during cooling. The DSC measurement sample was cut out from the vicinity of the center of a 100 × 100 × 1 mm flat plate.
(B) Bending strength, deflection rate, Charpy impact strength:
Using Toshiba Machine Company IS-100, the cylinder was set at 280 ° C., and after obtaining a molded product according to ISO 527-1 under the condition of a mold temperature of 130 ° C., each test was carried out.
Bending strength and deflection rate: Measured according to ISO-178.
Charpy impact strength: measured according to ISO-179-1eA.
(C) Gross value:
100 × 100 × 2mm thickness using Toshiba Machine IS-100, resin temperature 280 ° C, mold temperature 120 ° C, injection pressure 90%, injection speed 10%, holding pressure 30%, holding pressure 20% After obtaining a molded product having a size of 5 mm, a gloss value of 85 ° was measured with a gloss meter (micro-TRI-gloss manufactured by BYK Gardner).
(D) Melt viscosity (Pa · s):
A capillary rheometer (Toyo Seiki Co., Ltd., product name Capillograph 1B) was used.
Capillary shape: hole diameter 1.0mm, length 30mm
Shear rate: 500 sec ⁻¹ (41 mm / min)
Measurement temperature: 265 ° C

(3) Gas assist moldability An injection molding machine provided with a gas injection facility for hollow injection molding was used. The pressurized fluid used nitrogen gas and adopted the nozzle injection method. The injection molding conditions were a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C., with the resin injection amount being about 70% of the mold cavity volume, and 1 second after injection, compressed nitrogen gas with a pressure of 200 kg / cm ² was injected into the gold It was injected into the injection resin from a movable needle placed in the mold cavity (time 3 seconds) and molded with a holding time of 30 seconds. The surface appearance and uneven thickness were evaluated according to the following criteria.
(E) Surface appearance ○: No appearance defect due to flow mark, jetting or bumps.
Δ: Appearance defect due to flow mark or jetting.
X: Appearance defect due to bumps.
(F) Uneven thickness ○: Almost uniform thickness of about 2 to 3 mm.
(Triangle | delta): There exists an uneven thickness part about 5 mm thick part and about 1 mm thin part.
X: Some gas leak traces.

  The polyamide resin composition used for mechanical properties, shear viscosity, various moldings and measurements was dried and used so that the moisture content was 0.08% or less in order to prevent fluctuation due to moisture mixing. The moisture content was measured at 200 ° C. using a Karl Fischer moisture content system, manufactured by Mitsubishi Chemical Corporation, CA-100 type.

Examples 1-3, Comparative Examples 1-4
In the production of the evaluation sample, each raw material was weighed at the ratio shown in Table 1, and other raw materials excluding glass fibers were mixed with a tumbler and then put into a hopper of a twin screw extruder of L / D = 32. The glass fiber was added while measuring from the second vent port of the twin screw extruder. The kneading temperature of the twin screw extruder is 230 to 320 ° C. The obtained fiber reinforced semi-aromatic polyamide resin composition pellets were molded into various samples for evaluation using an injection molding machine. The evaluation results are shown in Table 1.
Separately, a resin composition having a blending ratio of 20% by mass of the amorphous polyamide (B) and 80% by mass of the semi-aromatic polyamide (A) is prepared, and the cooling crystallization temperature (Tc) of the semi-aromatic polyamide (A) is prepared. The lowering effect of ₂ ) was confirmed. The evaluation results are shown in Table 1.

In Examples 1 to 3, since the difference in SP value between the amorphous polyamide and the semi-aromatic polyamide 10T / 11 is within a specific range, the effect of reducing the crystallization of the polyamide 10T / 11 by the amorphous polyamide is sufficient. Therefore, the gloss value is very high and the appearance is good. Comparative Examples 1 and 2, since the amorphous polyamide is outside the difference in SP value specified with the polyamide 10T / 11, small effect of reduction of Tc _2, crystallization-reducing effect is low. In Comparative Example 3 in which amorphous polyamide is not added, the crystallization speed of the polyamide 10T / 11 is too high, so that the glass fiber floats conspicuously and the appearance of the molded product is remarkably poor. In Comparative Example 4, since the amount of amorphous polyamide added is too small, the effect of reducing crystallization is insufficient.

  The semi-aromatic polyamide resin composition of the present invention is required not only to have a small change in water absorption dimension and a change in flexural modulus due to water absorption, but also to have an excellent appearance even in a glass fiber reinforced molded product. It can be used for electrical appliances such as mobile phones, portable music listening products, portable video viewing products, and housing materials for portable personal computers.

Claims (5)

It contains 2-40 parts by mass of amorphous polyamide (B) with respect to 100 parts by mass of semi-aromatic polyamide (A), and semi-aromatic polyamide (A) and amorphous polyamide (B) are the following (a And a semi-aromatic polyamide resin composition characterized by satisfying the requirements of (b) and (b).
(A) An amide unit (b1) in which the amorphous polyamide (B) comprises a diamine component having a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms ) and possess the said amide units (b1) other than the amide units (b2), the amide units (b1) other than the amide units (b2) is dicyclohexylmethane having an alkyl group of 1 to 5 carbon atoms as a substituent A diamine component having an amide unit other than (b1) consisting of a diamine component having a skeleton and an aliphatic dicarboxylic acid component having 8 to 18 carbon atoms, a dicyclohexylmethane skeleton having an alkyl group having 1 to 5 carbon atoms as a substituent, and isophthalic acid A small amount selected from amide units consisting of components and amide units consisting of aminocarboxylic acids or lactams having 8 to 18 carbon atoms. Both 1 Tanedea Ru copolyamide.
(B) The difference in SP value between the semi-aromatic polyamide (A) and the amorphous polyamide (B) is -1.0 to 1.0. Semi-aromatic polyamide (A) is, in claim 1 is a copolyamide consisting of 50-2 mol% (a) decane terephthalamide units 50-98 mol% and (b) undecanamide units or / and dodecane amide units The semi-aromatic polyamide resin composition described. In the resin composition in which the amorphous polyamide (B) is 20% by mass of the amorphous polyamide (B) and 80% by mass of the semi-aromatic polyamide (A), the temperature-decreasing crystal of the semi-aromatic polyamide (A) temperature (Tc ₂₎ of those to lower 8 ° C. or higher according to claim 1 or 2 semiaromatic polyamide resin composition according to. When the melt viscosity of the amorphous polyamide (B) is (η _B ) and the melt viscosity of the semi-aromatic polyamide (A) is (η _A ) at 265 ° C. and a shear rate of 500 sec ⁻¹ , [1 _{- (η B) / (η} a)] is semi-aromatic polyamide resin composition according to any one of claims 1 to 3 which is -0.3～0.3. The semi-aromatic polyamide resin composition according to any one of claims 1 to 4, which is used for fluid-assisted molding.