AU2021106202A4

AU2021106202A4 - In-situ polymerization flame retardant, preparation method thereof, and molding composition composed thereof

Info

Publication number: AU2021106202A4
Application number: AU2021106202A
Authority: AU
Inventors: Min Cao; Huan CHANG; Xianbo Huang; Sujun JIANG; Zhongquan PENG; Mingchen XIE; Kun YAN; Nanbiao Ye; Chuanhui ZHANG
Original assignee: Kingfa Science and Technology Co Ltd
Current assignee: Kingfa Science and Technology Co Ltd
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2021-11-04
Anticipated expiration: 2029-08-20

Abstract

The invention discloses an in-situ polymerization flame retardant, which is derived from the following monomers: diacid monomer A: Al is terephthalic acid, A2 is phosphorus diacid monomer of reactive flame retardant containing aromatic ring, Al + A2 = 100mol%, Al = 50-90mol%, A2 = 10-50mol%; Diamine monomer B: one or more diamine monomers containing 4-36 carbon atoms. The invention obtains a novel flame retardant by in-situ polymerization of phosphorus series reactive flame retardant diacid monomer containing aromatic ring in semi aromatic polyamide oligomer, which has the advantages of no precipitation in semi aromatic polyamide, does not affect other properties of semi aromatic polyamide, and has excellent flame retardant performance.

Description

EDITORIAL NOTE 2021106202

There are 7 pages of description only.

In-situ polymerization flame retardant, preparation method thereof, and molding composition composed thereof

TechnicalField The invention relates to the technical field of new polymer materials, in particular to an in-situ polymerization flame retardant, a preparation method thereof and a molding composition composed thereof.

Background Technique Polyamide is the most widely used engineering plastic and has important applications in the fields of electronic appliances and household appliances. However, the flammability of polyamide greatly limits the application and promotion of polyamide. Therefore, the flame retardant modification of polyamide is of great significance. At present, polyamide flame retardant modifiers are divided into halogen-containing flame retardant modifiers and halogen-free flame retardant modifiers. However, halogen-containing flame retardant materials will produce a large number of halogen-containing toxic corrosive gases during combustion, resulting in secondary harm. With the increasingly strict requirements of environmental protection, the demand for halogen-free flame retardant materials is becoming more and more urgent. Halogen free flame retardant modifiers mainly include phosphorus flame retardant, nitrogen flame retardant and silicon flame retardant, among which the flame retardant effect of phosphorus flame retardant is the best. Generally, phosphorus containing inorganic salts are mostly used in phosphorus based flame retardants. For example, patent CN100564454C discloses a hypophosphite flame retardant modified polyamide; However, this type of flame retardant is a small molecular inorganic salt, which has poor compatibility with the polymer resin matrix. It is easy to produce uneven distribution problems such as agglomeration, precipitation or migration to the material surface, which affects the properties of the material. IN US5859147A an alkyl compound containing phosphate structure is synthesized, which can solve the problem of surface precipitation of flame retardant to a certain extent, but the structure of the compound determines that it has better compatibility only with amorphous polyamide. It only solves the problem of surface migration of flame retardant in amorphous polyamide, but for crystallization / semi crystalline type semi aromatic polyamides it has no effect.

Summary of the Invention The invention aims to overcome the above technical defects and provide an in-situ polymerization flame retardant, which is an in-situ polymerization semi aromatic polyamide oligomer, which has the advantages of no precipitation in the semi aromatic polyamide and no influence on other properties of the semi aromatic polyamide. The invention also provides a preparation method of the in-situ polymerization flame retardant. Another object of the invention is to provide a polyamide molding composition added with the in-situ polymerization flame retardant of the invention, which has the advantages of good flame retardant effect and good mechanical properties. The invention is realized by the following technical scheme: An in-situ polymerization flame retardant derived from the following monomers:

Diacid monomer A: Al is terephthalic acid, A2 is phosphorus reactive flame retardant diacid monomer containing aromatic ring, Al + A2 = 100mol%, Al = 50-90mol%, A2 = 10-50mol%; Diamine monomer B: one or more diamine monomers containing 4-36 carbon atoms. The phosphorus diacid monomer of reactive flame retardant containing aromatic ring is selected from at least one of 3-hydroxyphenylphosphoryl propionic acid(CEPPA), bis (p-carboxyphenyl) phenyl phosphine oxide(BCPPO), bis (p-carboxyphenyl) methyl phosphine oxide(BCMPO), bis (p-carboxyphenyl) ethyl phosphine oxide(BCEPO), [(6-oxy-6H-dibenzo-(c,e)(1,2) oxyphosphinohexacyclo-6- one) - methyl] - succinic acid(DDP); The preferred phosphorus diacid monomer of reactive flame retardant containing aromatic ring does not contain nitrogen element. Preferably, the phosphorus diacid monomer of reactive flame retardant containing aromatic ring is selected from [(6-oxy-6H-dibenzo - (c, e) (1,2) - oxyphosphahexyl-6-one) - methyl] - succinic acid, and its structural formula is as follows:

OH

HOW O-Pmo

The relative viscosity of in-situ polymerization flame retardant is 1.2-1.5. The test conditions are °C ± 0.01 °C and the concentration of in-situ polymerization flame retardant is 10mg / ml in 98% concentrated sulfuric acid. The invention uses relative viscosity to characterize the molecular weight of the in-situ polymerization flame retardant. When the in-situ polymerization flame retardant reaches a certain range of relative viscosity, it has well anti precipitation effect, which is reflected in the better mechanical properties of the polyamide molding composition composed of it. Preferably, the content of A2 in diacid monomer A is 15-40mol%. Underthe optimizedA2 content, the preparation difficulty, flame retardancy and precipitation resistance are well balanced, which has more application value. The content of A2 can be any of 15mol% - 40mol%, specifically mol%, 17mol%, 19mol%, 21mol%, 23mol%, 25mol%, 27mol%, 29mol%, 31mol%, 33mol%, mol%, 37mol%, 39mol% and 40mol%. The diamine monomer B is selectedfrom at least one of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptadiamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanonediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1-butyl-1,2-ethylenediamine, 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, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pe ntanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptadiamine, 2,3-dimethyl-1,7-heptadiamine, 2,4-dimethyl-1,7-heptadiamine,

2,5-dimethyl-1,7-heptadiamine, 2-methyl-1,8-octanediamine, 3-methyl-1, 8-octanediamine, 4-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, 5-methyl-1,9-nonyldiamine; Preferably, at least one selected from 1,10-decanediamine and 1,6-hexanediamine. The preparation method of the in-situ polymerization flame retardant comprises the following steps: weighing the diacid monomer A, diamine monomer B, catalyst (which can be sodium hypophosphite) and deionized water into the high-temperature and high-pressure reactor, charging and changing the air to make the atmosphere in the reactor nitrogen, raising the temperature to 160-180 °C, constant temperature reaction for 0.5 hours, continuing to raise the temperature to 200-210 °C and constant temperature reaction for 0.5 hours, continue heating to 240-250 °C, constant temperature reaction for 1 hour, drainage for about 0.5 hours, and discharging to obtain in-situ polymerization flame retardant. The polyamide molding composition composed of the above in-situ polymerization flame retardant comprises the following components by weight: Semi aromatic polyamide 40-100 parts; In-situ polymerization flame retardant 5-45 parts. The content of terephthalic acid in the diacid monomer of the semi aromatic polyamide is -100mol%; The diamine monomer of the semi aromatic polyamide is selected from one or more diamines with 4-36 carbon atoms; The diamine with 4-36 carbon atoms is selected from at least one of straight chain aliphatic diamines such as 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptadiamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanonediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,36-hexadecanediamine; at least one of branched aliphatic diamines such as 1-butyl-1,2-ethylenediamine, 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,2,3-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, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptadiamine, 2,3-dimethyl-1,7-heptadiamine, 2,4-dimethyl-1,7-heptadiamine, 2,5-dimethyl-1,7-heptadiamine, 2-methyl-1,8-octanediamine, 3-methyl-1, 8-octanediamine, 4-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,5-methyl-1,9-nonanediamine; at least one of alicyclic diamines such as Cyclohexanediamine, methylcyclohexanediamine, isophorone diamine, norbornene dimethylamine and tricyclic decanedimethylamine, preferably at least one of 1,10-decane diamine and 1,6-hexanediamine. The relative viscosity of the semi aromatic polyamide resin with a concentration of 10mg / ml measured in 98% concentrated sulfuric acid at 25 °C ± 0.01 °C is 1.7-2.8, preferably 2.0-2.3.

It also includes at least one of reinforcing fiber, filler, additive and processing aid by weight. The average length of the reinforcing fiber is 0.01mm-20mm, preferably 0.1mm-6mm; The aspect ratio is 5:1-3500:1, preferably 30:1-600:1; Based on the total weight percentage of the polyamide molding composition, the content of the reinforcing fiber is 10wt% - 50wt%, more preferably wt% - 40wt%; The reinforcing fiber is an inorganic reinforcing fiber or an organic reinforcing fiber, and the inorganic reinforcing fiber includes but is not limited to one or more of glass fiber, potassium titanate fiber, metal clad glass fiber, ceramic fiber, wollastonite fiber, metal carbide fiber, metal curing fiber, asbestos fiber, alumina fiber, silicon carbide fiber, gypsum fiber or boron fiber. The average particle size of the filler is 0.001 p m-100 p m. Preferably 0.01 p m-50 p m. Including but not limited to one or more of potassium titanate whiskers, zinc oxide whiskers, aluminum borate whiskers, wollastonite, zeolite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicate, alumina, silicon oxide, magnesium oxide, zirconia, titanium oxide, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass beads, ceramic beads, boron nitride, silicon carbide or silicon dioxide. Mica can be ordinary mica, sericite, fluorophlogopite (synthetic mica), etc; Montmorillonite can be ordinary montmorillonite, Lithium Montmorillonite, or montmorillonite modified in other ways. The invention has no special requirements for additives and processing aids of polyamide molding composition, and the additives can be toner, anti-ultraviolet agent or other weather resistant agents; processing aids can be lubricants, antioxidants, etc., and can be selected according to the processing conditions of polyamide molding composition and other properties required. Compared with the prior art, the invention has the following beneficial effects: The invention obtains an in-situ polymerization flame retardant by in-situ copolymerization of phosphorus diacid monomer of reactive flame retardant containing aromatic ring in semi aromatic polyamide oligomer, and the semi aromatic polyamide molding composition composed of it has good flame retardant and mechanical properties. It avoids the uneven distribution of inorganic small molecular phosphorus flame retardants in the composition after flame retardant modification, such as agglomeration, precipitation or migration to the material surface, and the technical problem that alkyl compounds containing phosphate structure have good compatibility only with amorphous polyamide.

Detailed Description of preferred Embodiment The invention is further described by the following embodiments, but it should not be understood as limiting the protection scope of the invention. The raw materials used in the embodiment and the proportion of the invention are from commercially available products. PA10T: Vicnyl 700; PA6T66: Vicnyl 400; Antioxidant: antioxidant 1098; Lubricant: polyethylene wax; OP935: diethyl hypophosphate; CEMPO: bis (2-carboxyethyl) methyl phosphine oxide;

Glass fiber: 568H, average length 4 mm, diameter 13 microns. Preparation method of in-situ copolymerization flame retardant: according to the monomer and molar content of in-situ copolymerization flame retardant in Table 1, weigh the diacid monomer A, diamine monomer B, sodium hypophosphite and deionized water into the high-temperature and high-pressure reactor, fill and change the atmosphere in the reactor to nitrogen, raise the temperature to 160-180 °C for constant temperature reaction for 0.5 hours, continue to raise the temperature to 200-210 °C and constant temperature reaction for 0.5 hours, continue heating to 240-250 °C, constant temperature reaction for 1 hour, drainage for about 0.5 hours, and discharge to obtain in-situ polymerization flame retardant. Preparation method of polyamide molding composition of examples and comparative examples: after mixing semi aromatic polyamide resin, flame retardant (in-situ copolymerization flame retardant or op935) and other additives in the high-speed mixer according to the formula, they are added into the twin-screw extruder through the main feeding port, and the reinforcing filler is fed side by side through the side feeding scale, extruded, cooled by water, granulated and dried, The polyamide molding composition is obtained. Various performance test methods: (1) Relative viscosity: refer to the standard GB/T 12006.1-1989, and use Ubbelohde viscometer to measure the relative viscosity of the product with a concentration of 0.25g/dL in 98% concentrated sulfuric acid at (25±0.01)°C (2) Tensile strength: refer to standard ISO 527 to measure the tensile strengthof resin materials. (3) Bending strength: refer to standard ISO 178 to measure the bending strength of resin materials. (4) Notched impact strength / notchless impact strength: refer to standard ISO 180 to measure the impact strength of resin materials. (5) UL94 flame retardant grade: measured according to GB /T2408-1996, and the sample size is 13cm X 1.3cm X 0.3cm. (6) Limiting oxygen index (LOI): measured according to the standard GB / t5454-1997, and the sample size is 12cm X 1cm X 0.4cm. Table 1: in-situ copolymerized flame retardants No. of the In-situ copolymerization flame A B C D E retardant In-situ copolymerization 10T10DDP 10T10DDP 10T10DDP 10T10DDP 6T6DDP flame retardant A2 accounts for mol% of 10 15 40 50 25 diacid monomer Relative viscosity 1.35 1.37 1.35 1.36 1.40 Continued Table 1: No. of the In-situ copolymerization flame F G H I J retardant In-situ copolymerization 1OT10CEP 10T10C 10T10BCPPO 10T10DDP 10T10DDP flame retardant PA EMPO A2 accounts for mol% of 15 15 15 15 15 diacid monomer Relative viscosity 1.42 1.41 1.13 1.56 1.41 Table 2: Formulations and performance test results of polyamide molding compositions of the examples and comparative examples(CE) Example Example 2 Example 3 Example 4 Semi-aromatic polyamide PA10T Resin content, parts 55 55 55 55 Flame retardant A B C D Flame retardant content, 15 15 15 15 parts Glass fiber, parts 29 29 29 29 Antioxidant, parts 0.5 0.5 0.5 0.5 Lubricant, parts 0.5 0.5 0.5 0.5 Tensile strength MPa 155 167 165 157 Bending strength MPa 245 265 263 250 Notched impact strength 11 12 12 11 2 kJ/m

Unnotched impact strength 36 41 40 35 kJ/m2 k/2

UL flame retardant grade VO VO VO VO LOI 34 36 36 34 Continued Table 2: Exam Examp Examp Examp CE1 CE2 ple5 le6 le7 le 8 Semi-aromaticpolyamide PA10T Resin content, parts 55 55 55 55 55 55 Flame retardant F G H I J OP935 Flame retardant content, parts 15 15 15 15 15 15 Glass fiber, parts 29 29 29 29 29 29 Antioxidant, parts 0.5 0.5 0.5 0.5 0.5 0.5 Lubricant, parts 0.5 0.5 0.5 0.5 0.5 0.5 Tensile strength MPa 162 164 133 142 125 110 Bending strength MPa 261 263 212 220 197 180 Notched impact strength 12 12 10 10 9 8 kJ/m2 k/2

Unnotched impact strength 38 39 31 33 27 25 kJ/m2 k/2

UL flame retardant grade VO VO VO VO V1 V2 LOI 35 35 33 33 31 30 Continued Table 2: Example 9 CE3 Semi-aromatic polyamide PA6T66 Resin content, parts 55 55

Flame retardant E OP935 Flame retardant content, parts 15 15 Glass fiber, parts 29 29 Antioxidant, parts 0.5 0.5 Lubricant, parts 0.5 0.5 Tensile strength MPa 190 119 Bending strength MPa 270 194 Notched impact strength kJ/m2 11 7 Unnotched impact strengthkJ/m2 65 38 UL flame retardant grade VO V2 LOI 36 30 It can be seen from examples 1-4 that the mechanical properties and flame retardancy of polyamide molding composition are better at the preferred A2 content. As can be seen from examples 2 /5 /6, the flame retardant monomer DDP is preferred. As can be seen from examples 2 /7 /8, the preferred relative viscosity range is 1.2-1.5. It can be seen from the comparative examples 1 / 2 / 3 that the in-situ copolymerization flame retardant of reactive flame retardant diacid monomer containing phosphorus and aromatic ring synthesized by the invention has better compatibility, strong precipitation resistance, less impact on the performance of semi aromatic polyamide resin itself and better flame retardant effect than the conventional (2-carboxyethyl) methyl phosphine oxide inorganic phosphorus flame retardant.

EDITORIAL NOTE 2021106202

There are 2 pages of claims only.

Claims

1. An in-situ polymerization flame retardant, which is characterized in that it is derived from the following monomers: Diacid monomer A: Al is terephthalic acid, A2 is phosphorus diacid monomer of reactive flame retardant containing aromatic ring, Al+ A2 = 100mol%, Al = 50-90mol%, A2 = 10-50mol%; Diamine monomer B: one or more diamine monomers containing 4-36 carbon atoms.

2. The in-situ polymerization flame retardant according to claim 1, which is characterized in that the phosphorus diacid monomer of reactive flame retardant containing aromatic ring is selected from at least one of 3-hydroxyphenylphosphoryl propionic acid, bis (p-carboxyphenyl) phenyl phosphine oxide, bis (p-carboxyphenyl) methyl phosphine oxide, bis (p-carboxyphenyl) ethyl phosphine oxide, [(6-oxy-6H-dibenzo-(c,e) (1,2)-oxyphosphinohexacyclo-6-one)-methyl] - succinic acid; Preferably, the phosphorus diacid monomer of reactive flame retardant containing aromatic ring is selected from [(6-oxy-6H-dibenzo-(c,e)(1,2)-oxyphosphohexacyclo-6-one)-methyl]- succinic acid.

3. The in-situ polymerization flame retardant according to claim 1, which is characterized in that the relative viscosity of the in-situ polymerization flame retardant is 1.2-1.5, the test condition is °C ± 0.01 °C, and the concentration of the in-situ polymerization flame retardant is 10mg/ ml in 98% concentrated sulfuric acid.

4. The in-situ polymerization flame retardant according to claim 1, which is characterized in that the content of A2 in diacid monomer A is 15-40mol%.

5. The in-situ polymerization flame retardant according to claim 1, which is characterized in that the diamine monomer B is selected from at least one of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptadiamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanonediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1-butyl-1,2-ethylenediamine, 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, 2,3-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, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptadiamine, 2,3-dimethyl-1,7-heptadiamine, 2,4-dimethyl-1,7-heptadiamine, 2,5-dimethyl-1,7-heptadiamine, 2-methyl-1,8-octanediamine, 3-methyl-1, 8-octanediamine, 4-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, 5-methyl-1,9-nonyldiamine; Preferably, it is selected from 1,10-decanediamine and 1,6-hexanediamine.

6. The preparation method of the in-situ polymerization flame retardant according to any one of claims 1-5, which is characterized in that it comprises the following steps: weigh diacid monomer A, diamine monomer B, catalyst, and deionized water into the high-temperature and high-pressure reactor, after filling and changing the atmosphere in the reactor to nitrogen, heat up to 160-180° C, react at a constant temperature for 0.5 hours, continue to heat up to 200-210° C, and react at a constant temperature for 0.5 hours, continue to heat up to 240-250 °C, and react at a constant temperature for 1 hour, drainage for about 0.5 hours, discharge to obtain in-situ polymerization flame retardant.

7. The polyamide molding composition composed of the in-situ polymerization flame retardant according to any one of claims 1-5, which is characterized in that it comprises the following components by weight: Semi aromatic polyamide 40-100 parts; In-situ polymerization flame retardant 5-45 parts.

8. The polyamide molding composition according to claim 7, which is characterized in that the content of terephthalic acid in the diacid monomer of the semi aromatic polyamide is -100mol%; The diamine monomer of the semi aromatic polyamide is selected from one or more diamines with 4-36 carbon atoms; The diamine with 4-36 carbon atoms is selected from at least one of straight chain aliphatic diamines such as 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptadiamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanonediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,36-hexadecanediamine; at least one of branched aliphatic diamines such as 1-butyl-1,2-ethylenediamine, 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,2,3-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, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptadiamine, 2,3-dimethyl-1,7-heptadiamine, 2,4-dimethyl-1,7-heptadiamine, 2,5-dimethyl-1,7-heptadiamine, 2-methyl-1,8-octanediamine, 3-methyl-1, 8-octanediamine, 4-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,5-methyl-1,9-nonanediamine; at least one of alicyclic diamines such as Cyclohexanediamine, methylcyclohexanediamine, isophorone diamine, norbornene dimethylamine and tricyclic decanedimethylamine, preferably at least one of 1,10-decane diamine and 1,6-hexanediamine.

9. The polyamide molding composition according to claim 7, which is characterized in that the relative viscosity of the semi aromatic polyamide resin with a concentration of 10mg / ml measured in 98% concentrated sulfuric acid at 25 °C ± 0.01 °C is 1.7-2.8, preferably 2.0-2.3.

10. The polyamide molding composition according to claim 7, which is characterized in that it further comprises at least one of reinforcing fiber, filler, additive and processing aid by weight.