WO2018133296A1 - Semi-aromatic polyamide resin, method for preparing same, and polyamide molding composition consisting of same - Google Patents

Abstract

A semi-aromatic polyamide resin, a method for preparing same, and a polyamide molding composition consisting of same. The semi-aromatic polyamide resin consists of the following components : (A) 20-95 wt% of PA6I homopolymer derived from 1,6-hexamethylenediamine and isophthalic acid; and (B) 5-80 wt% of PA6T homopolymer derived from 1,6-hexamethylenediamine and terephthalic acid, wherein (A)+(B)=100 wt%. By adding a certain quantity of the PA6I homopolymer into the PA6T homopolymer, the melting point of the PA6T homopolymer can be significantly reduced to below a decomposition temperature, so that the processability of the PA6T homopolymer is improved; the melting point of the prepared semi-aromatic polyamide resin is reduced, and normal processing can thus be performed; the polyamide molding composition consisting of the semi-aromatic polyamide resin has good processability and excellent surface properties.

Description

Semi-aromatic polyamide resin, preparation method thereof and polyamide molding composition composed thereof Technical field

The invention relates to the technical field of engineering plastics, in particular to a semi-aromatic polyamide resin, a preparation method thereof and a polyamide molding composition composed thereof.

Background technique

The PA6T homopolymer is polymerized from 1,6-hexanediamine and terephthalic acid. However, its melting point is as high as 370 ° C, which is higher than its decomposition temperature and has no practical value.

For the above problems with PA6T homopolymers, there are two general solutions in the industry: copolymerization and extension of the carbon chain length. The former refers to the addition of other monomers in the polymerization system, such as adipic acid, sebacic acid, etc., thereby reducing the melting point of the PA6T homopolymer to below the decomposition temperature, and smooth processing; the latter refers to the use of long carbon chain diamine instead of hexan The amine can reduce the concentration of the amide bond while lowering the melting point, thereby obtaining a polyamide resin having good processability and low water absorption.

However, both of the above solutions must be solved from the formulation design stage, often requiring changes to the polymerization process and equipment, and the cost is high.

The present invention has unexpectedly discovered that the addition of a certain amount of PA6I homopolymer to the PA6T homopolymer can significantly lower the melting point of the PA6T homopolymer to below the decomposition temperature, thereby improving the processing properties of the PA6T homopolymer.

Summary of the invention

In order to overcome the shortcomings and deficiencies of the prior art, it is a primary object of the present invention to provide a semi-aromatic polyamide resin capable of significantly reducing the melting point of a PA6T homopolymer.

Still another object of the present invention is to provide a process for producing the above semi-aromatic polyamide resin.

Another object of the present invention is to provide a polyamide molding composition comprising the above semi-aromatic polyamide resin which can remarkably improve processability and has excellent surface characteristics.

The invention is achieved by the following technical solutions:

A semi-aromatic polyamide resin consisting, by weight, of the following components:

(A) 20-95% by weight of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

(B) 5-80% by weight of a PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

Among them, (A) + (B) = 100% by weight.

As a preferred embodiment of the present invention, the semi-aromatic polyamide resin is composed of the following components in percentage by weight:

(A) 30-85 wt% of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

(B) 15-70% by weight of a PA 6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

Among them, (A) + (B) = 100% by weight.

As a more preferred embodiment of the present invention, the semi-aromatic polyamide resin is composed of the following components in percentage by weight:

(A) 40-70% by weight of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

(B) 30-60% by weight of a PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

Among them, (A) + (B) = 100% by weight.

The melting point of the semi-aromatic polyamide resin of the present invention is 240-340 ° C with reference to ASTM D3418-2003, which is significantly lower than the melting point of PA6T, improving the processing property of PA6T.

The semi-aromatic polyamide resin of the present invention is amorphous, microcrystalline or amorphous.

The PA6T homopolymer of the present invention can be synthesized by conventional techniques in the art, such as by the following method:

Add hexamethylenediamine, terephthalic acid, benzoic acid, sodium hypophosphite and water to an autoclave equipped with a magnetic coupling stirring, a condenser tube, a gas phase port, a feed port, and a pressure explosion port, and vacuum-fill the high-purity nitrogen gas. As a shielding gas, the temperature was raised to 220 ° C in 2 hours under stirring, and the reaction mixture was stirred at 220 ° C for 1 hour, and then the temperature of the reactant was raised to 250 ° C under stirring, and the reaction was kept at a constant temperature of 250 ° C and 3.6 MPa. The pressure was continued for 2 hours under constant pressure, and the pressure was kept constant by removing the formed water. After the completion of the reaction, the prepolymer was vacuum dried at 80 ° C for 24 hours to obtain a prepolymerized product. The solid phase was thickened under vacuum at 290 ° C and 50 Pa to obtain a PA6T homopolymer.

The PA6T homopolymer of the present invention can be synthesized by conventional techniques in the art, and is also commercially available.

The invention also discloses a preparation method of the semi-aromatic polyamide resin, comprising the following steps:

The PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid and the PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid are uniformly mixed in a high-mixer. It is pulverized into a powder of 5-10 um in a pulverizer; the powder is introduced into a twin-screw extruder through a main feed port, extruded, cooled by water, granulated and dried to obtain a semi-aromatic polyamide resin.

The present invention also discloses a polyamide molding composition comprising the above semi-aromatic polyamide resin, which comprises, by weight fraction, the following components:

Semi-aromatic polyamide resin 30-100 parts;

Reinforcing filler 0-70 parts;

Additive 0-50 parts;

The content of the reinforcing filler is preferably from 10 to 50 parts, more preferably from 15 to 40 parts, based on the total weight of the polyamide molding composition;

If the content of the reinforcing filler is too low, the mechanical properties of the polyamide molding composition are poor; the content of the reinforcing filler is too high, and the surface of the polyamide molding composition product is seriously suspended, which affects the appearance of the product.

The reinforcing filler has a fibrous shape and an average length of 0.01 mm to 20 mm, preferably 0.1 mm to 6 mm; and an aspect ratio of 5:1 to 2000:1, preferably 30:1 to 600:1. When the content of the fibrous reinforcing filler is within the above range, the polyamide molding composition exhibits a high heat distortion temperature and an increased high temperature rigidity.

The reinforcing filler is an inorganic reinforcing filler or an organic reinforcing filler;

The inorganic reinforcing filler is selected from the group consisting of glass fiber, potassium titanate fiber, metal clad glass fiber, ceramic fiber, wollastonite fiber, metal carbide fiber, metal curable fiber, asbestos fiber, alumina fiber, silicon carbide fiber, One or more of gypsum fiber or boron fiber, preferably glass fiber;

The use of glass fibers not only improves the moldability of the polyamide molding composition, but also improves mechanical properties such as tensile strength, flexural strength and flexural modulus, and improves heat resistance, for example, when the thermoplastic resin composition is molded. Heat distortion temperature.

The organic reinforcing filler is selected from the group consisting of aramid fibers and/or carbon fibers.

The reinforcing filler has a non-fibrous shape such as a powder, a granule, a plate, a needle, a woven fabric or a felt, and has an average particle diameter of from 0.001 μm to 100 μm, preferably from 0.01 μm to 50 μm.

When the average particle diameter of the reinforcing filler is less than 0.001 μm, it will result in poor melt processability of the polyamide resin; when the average particle diameter of the reinforcing filler is more than 100 μm, it will result in poor surface appearance of the injection molded article.

The average particle diameter of the above reinforcing filler is determined by an adsorption method, which may be selected from potassium titanate whiskers, zinc oxide whiskers, aluminum borate whiskers, wollastonite, zeolite, sericite, kaolin, mica, talc, clay, Pyrophyllite, bentonite, montmorillonite, hectorite, synthetic mica, asbestos, aluminosilicate, alumina, silica, magnesia, zirconia, titania, iron oxide, calcium carbonate, magnesium carbonate, dolomite, One or more of calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass beads, ceramic beads, boron nitride, silicon carbide or silicon dioxide.

These reinforcing fillers may be hollow; in addition, for swellable layered silicates such as bentonite, montmorillonite, hectorite, and synthetic mica, organication by cation exchange of interlayer ions with an organic ammonium salt may be used. Montmorillonite.

In order to obtain a more excellent mechanical property of the polyamide molding composition, the inorganic reinforcing filler may be functionally treated with a coupling agent.

Wherein the coupling agent is selected from the group consisting of an isocyanate compound, an organosilane compound, an organic titanate compound, an organoborane compound, and an epoxy compound; preferably an organosilane compound;

The organosilane compound is selected from the group consisting of an epoxy group-containing alkoxysilane compound, a mercapto group-containing alkoxysilane compound, a urea group-containing alkoxysilane compound, and an isocyanate group-containing alkoxysilane compound. One or more of an alkoxysilane compound containing a terminal amino group, an alkoxysilane compound containing a hydroxyl group, an alkoxysilane compound containing a carbon-carbon unsaturated group, and an alkoxysilane compound containing an acid anhydride group.

The epoxy group-containing alkoxysilane compound is selected from the group consisting of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4- One or more of epoxycyclohexyl)ethyltrimethoxysilane;

The mercapto group-containing alkoxysilane compound is selected from the group consisting of γ-mercaptopropyltrimethoxysilane and/or γ-mercaptopropyltriethoxysilane;

The ureido group-containing alkoxysilane compound is selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-(2-ureidoethyl)-terminated aminopropyl group One or more of a trimethoxysilane;

The isocyanate group-containing alkoxysilane compound is selected from the group consisting of γ-isocyanatepropyltriethoxysilane, γ-isocyanatepropyltrimethoxysilane, γ-isocyanatepropylmethyldimethoxysilane, γ-Isocyanatepropylmethyldiethoxysilane, γ-Isocyanatepropylethyldimethoxysilane, γ-Isocyanatepropylethyldiethoxysilane, γ-Isocyanatepropyltrichloride One or several of silanes;

The terminal amino group-containing alkoxysilane compound is selected from the group consisting of γ-(2-terminal aminoethyl)-terminated propylmethyldimethoxysilane and γ-(2-terminal aminoethyl) terminal One or more of aminopropyltrimethoxysilane and γ-terminal aminopropyltrimethoxysilane;

The hydroxyl group-containing alkoxysilane compound is selected from the group consisting of γ-hydroxypropyltrimethoxysilane and/or γ-hydroxypropyltriethoxysilane;

The alkoxysilane compound containing a carbon-carbon unsaturated group is selected from the group consisting of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and N-β-(N-vinylbenzyl One or more of terminal aminoethyl)-γ-terminal aminopropyltrimethoxysilane hydrochloride;

The acid anhydride group-containing alkoxysilane compound is selected from the group consisting of 3-trimethoxysilylpropyl succinic anhydride;

The organosilane compound is preferably γ-methacryloxypropyltrimethoxysilane, γ-(2-terminal aminoethyl)-terminated propylmethyldimethoxysilane, γ-( 2-terminal aminoethyl)-terminated aminopropyltrimethoxysilane, γ-terminal aminopropyltrimethoxysilane or 3-trimethoxysilylpropyl succinic anhydride.

The inorganic reinforcing filler may be surface-treated by a conventional method using the above organosilane-based compound, and then melt-kneaded with a polyamide resin to prepare the polyamide molding composition.

It is also possible to directly add an organosilane compound to the in-situ blending while the inorganic reinforcing filler is melt-kneaded with the polyamide resin.

Wherein, the coupling agent is used in an amount of 0.05% by weight to 10% by weight, preferably 0.1% by weight to 5% by weight based on the weight of the inorganic reinforcing filler.

When the amount of the coupling agent is less than 0.05% by weight, the effect of improving the mechanical properties is not obtained; when the amount of the coupling agent is more than 10% by weight, the inorganic reinforcing filler is liable to agglomerate and is poorly dispersed in the polyamide resin. The risk eventually leads to a decline in mechanical properties.

The additive is selected from one or more of a flame retardant, an impact modifier, other polymers, and a processing aid;

The other polymer is one or more of an aliphatic polyamide, a polyolefin homopolymer, an ethylene-α-olefin copolymer, and an ethylene-acrylate copolymer;

The processing aid is selected from one or more of an antioxidant, a heat resistant stabilizer, a weathering agent, a mold release agent, a lubricant, a pigment, a dye, a plasticizer, and an antistatic agent.

The flame retardant is a flame retardant or a combination of a flame retardant and a flame retardant assistant, and the content thereof is preferably 0-40 parts based on the total weight of the polyamide molding composition; the flame retardant content is too low to cause flame retardancy The effect is deteriorated, and the flame retardant content is too high, resulting in a decrease in mechanical properties of the material.

The flame retardant is a halogen flame retardant or a halogen free flame retardant;

The halogen-based flame retardant is selected from the group consisting of brominated polystyrene, brominated polyphenylene ether, brominated bisphenol A type epoxy resin, brominated styrene-maleic anhydride copolymer, brominated epoxy resin, and brominated One or more of a phenoxy resin, decabromodiphenyl ether, decabromobiphenyl, a brominated polycarbonate, a perbromotricyclopentadecane or a brominated aromatic crosslinked polymer, preferably a bromine Polystyrene

The halogen-free flame retardant is selected from one or more of a nitrogen-containing flame retardant, a phosphorus-containing flame retardant or a nitrogen and phosphorus-containing flame retardant; preferably a phosphorus-containing flame retardant.

The phosphorus-containing flame retardant is selected from the group consisting of aryl phosphate monophosphate, aryl phosphate bisphosphate, dimethyl alkylphosphonate, triphenyl phosphate, tricresyl phosphate, tris(xylylene) phosphate, and C. One or more of a benzene phosphate, a butyl benzene phosphate or a phosphinate; preferably a phosphinate;

The phosphinate compound is represented by a compound represented by, for example, the following formula I and/or II.

In Formula I and Formula II, R ¹ and R ² may be the same or different and each represents a linear or branched C1-C6-alkyl group, an aryl group or a phenyl group. R ³ represents a linear or branched C1-C10-alkylene group, a C6-C10-arylene group, a C6-C10-alkylarylene group, or a C6-C10-arylalkylene group. M represents a calcium atom, a magnesium atom, an aluminum atom and/or a zinc atom. M is 2 or 3, n is 1 or 3, and x is 1 or 2.

More specific examples of the phosphinate compound include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate , magnesium ethyl methylphosphinate, aluminum ethyl methylphosphinate, zinc ethyl methylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, diethylphosphinic acid Aluminum, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-propylphosphinate, zinc methyl-n-propylphosphinate, A burnt two (a Calcium phosphonate) calcium, methane bis(methylphosphinic acid) magnesium, methane bis(methylphosphinic acid) aluminum, methane bis(methylphosphinic acid) zinc, benzene-1,4-(dimethyl Phosphinic acid) calcium, benzene-1,4-(dimethylphosphinic acid) magnesium, benzene-1,4-(dimethylphosphinic acid) aluminum, benzene-1,4-(dimethylphosphinium) Acid) zinc, calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, diphenyl Magnesium phosphinate, aluminum diphenylphosphinate, zinc diphenylphosphinate, etc., preferably calcium dimethyl phosphinate, aluminum dimethyl phosphinate, zinc dimethyl phosphinate, ethyl Methylphosphinic acid I丐, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, More preferred is aluminum diethylphosphinate.

A phosphinate compound as a flame retardant can be easily obtained from the market. Examples of commercially available phosphinate compounds include EXOLIT OP1230, OP1311, OP1312, OP930, OP935, and the like, manufactured by Clariant.

The polyamide molding composition of the present invention comprising the above semi-aromatic copolyamide resin, the additive component may further comprise up to 45 wt% of one or more impact modifiers based on the total weight of the polyamide molding composition. The agent is preferably from 5% by weight to 30% by weight.

Wherein, the impact modifier may be natural rubber, polybutadiene, polyisoprene, polyisobutylene, butadiene and/or isoprene and styrene or with styrene derivatives and copolymerization with others a copolymer of a monomer, a hydrogenated copolymer, and/or a copolymer obtained by grafting or copolymerizing with an anhydride, (meth)acrylic acid or an ester thereof; the impact modifier may also have a crosslinked elastomer a graft rubber of a core composed of butadiene, isoprene or alkyl acrylate, and having a graft shell composed of polystyrene or may be a non-polar or polar olefin a polymer or copolymer, such as ethylene propylene rubber, ethylene-propylene-diene rubber, or ethylene-octene rubber, or ethylene-vinyl acetate rubber, or by grafting or with an anhydride, (meth)acrylic acid or its ester a non-polar or polar olefin homopolymer or copolymer obtained by copolymerization; the impact modifier may also be a carboxylic acid-functionalized copolymer such as poly(ethylene-co-(meth)acrylic acid) or poly (ethylene-1-olefin-co-(meth)acrylic acid) wherein the 1-olefin is an alkene or has more than 4 The atomic unsaturated (meth) acrylate includes those copolymers in which acid groups are neutralized to some extent by metal ions.

An impact modifier based on styrene monomer (styrene and styrene derivatives) and other vinyl aromatic monomers, is a block copolymer composed of an alkenyl aromatic compound and a conjugated diene, and A hydrogenated block copolymer composed of an alkenyl aromatic compound and a conjugated diene, and a combination of these types of impact modifiers. The block copolymer comprises at least one block a derived from an alkenyl aromatic compound and at least one block b derived from a conjugated diene. In the case of hydrogenated block copolymers, the proportion of aliphatically unsaturated carbon-carbon double bonds is reduced by hydrogenation. Suitable block copolymers are di-, tri-, tetra- and multi-block copolymers having a linear structure. However, branched and star structures can also be used in accordance with the present invention. Branched block copolymers are obtained in a known manner, for example by grafting of the polymer "side branches" to the polymer backbone.

Other alkenyl aromatic compounds which may be used together with styrene or in the form of a mixture with styrene are in aromatic A ring and/or a vinyl aromatic monomer substituted by a C1-20 hydrocarbon group or a halogen atom on a C=C double bond.

Examples of alkenyl aromatic monomers are styrene, p-methyl styrene, alpha-methyl styrene, ethyl styrene, t-butyl styrene, vinyl toluene, 1,2-diphenylethylene, 1,1-diphenylethylene, vinylxylene, vinyltoluene, vinylnaphthalene, divinylbenzene, bromostyrene, and chlorostyrene, and combinations thereof. Preference is given to styrene, p-methylstyrene, α-methylstyrene, and vinylnaphthalene.

Preference is given to using styrene, α-methylstyrene, p-methylstyrene, ethylstyrene, tert-butylstyrene, vinyltoluene, 1,2-diphenylethylene and 1,1-diphenylethylene. Or a mixture of these substances. It is particularly preferred to use styrene. However, alkenylnaphthalene can also be used.

Examples of diolefin monomers which may be used are 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3 - pentadiene, 1,3-hexadiene, isoprene, chloroprene and piperylene. Preference is given to 1,3-butadiene and isoprene, in particular 1,3-butadiene (hereinafter referred to as butadiene in the abbreviated form).

The alkenyl aromatic monomer used preferably comprises styrene, and the diene monomer used preferably comprises butadiene, which means that a styrene-butadiene block copolymer is preferred. The block copolymers are generally prepared by anionic polymerization in a manner known per se.

In addition to the styrene monomer and the diene monomer, other additional monomers can be used simultaneously. The proportion of the comonomer is preferably from 0 to 50% by weight, particularly preferably from 0 to 30% by weight, particularly preferably from 0 to 15% by weight, based on the total amount of the monomers used. Examples of suitable comonomers are respectively acrylates, especially C1 to C12 alkyl acrylates, such as n-butyl acrylate or 2-ethylhexyl acrylate, and methacrylates, especially methacrylic acid C1 to C12. Alkyl esters such as methyl methacrylate (MMA). Other possible comonomers are (meth)acrylonitrile, glycidyl (meth)acrylate, vinyl methyl ether, diallyl and divinyl ethers of diols, divinylbenzene and vinyl acetate. ester.

In addition to the conjugated diene, the hydrogenated block copolymer further comprises, if appropriate, a lower hydrocarbon moiety such as ethylene, propylene, 1-butene, dicyclopentadiene or a non-conjugated diene. The proportion of unreduced aliphatic unsaturated bonds derived from block b in the hydrogenated block copolymer is less than 50%, preferably less than 25%, especially less than 10%. The aromatic moiety derived from block a is reduced to an extent of up to 25%. By hydrogenation of a styrene-butadiene copolymer and hydrogenation of a styrene-butadiene-styrene copolymer, a hydrogenated block copolymer, namely a styrene-(ethylene-butylene) diblock copolymer and benzene, is obtained. Ethylene-(ethylene-butylene)-styrene triblock copolymer.

The block copolymer preferably comprises from 20% by weight to 90% by weight of block a, in particular from 50% by weight to 85% by weight, of block a. The diolefin can be introduced into the block b in a 1,2-orientation or a 1,4-position.

The block copolymer has a molar mass of from 5000 g/mol to 500,000 g/mol, preferably from 20,000 g/mol to 300,000 g/mol, in particular from 40,000 g/mol to 200,000 g/mol.

Suitable hydrogenated block copolymers are commercially available products such as (Kraton Polymer) G1650, G1651 And G1652, and (Asahi Chemicals) H1041, H1043, H1052, H1062, H1141 and H1272.

Examples of non-hydrogenated block copolymers are polystyrene-polybutadiene, polystyrene-poly(ethylene-propylene), polystyrene-polyisoprene, poly(?-methylstyrene)-poly Butadiene, polystyrene-polybutadiene-polystyrene (SBS), polystyrene-poly(ethylene-propylene)-polystyrene, polystyrene-polyisoprene-polystyrene, and Poly(α-methylstyrene) polybutadiene-poly(α-methylstyrene), and combinations thereof.

Suitable non-hydrogenated block copolymers which are commercially available are available under the trade names (Phillips), (Shell), (Dexco) and (Kuraray).

The polyamide molding composition of the present invention comprising the above semi-aromatic copolyamide resin, the additive component may further comprise other polymers selected from the group consisting of aliphatic polyamides, polyolefin homopolymers, and ethylene. -α-olefin copolymer, ethylene-acrylate copolymer.

The aliphatic polyamides include, but are not limited to, aliphatic diacids and aliphatic diamines derived from 4 to 20 carbon atoms, or lactams of 4 to 20 carbon atoms, or aliphatic groups of 4 to 20 carbon atoms. One or more of a polymer of a diacid, an aliphatic diamine, and a lactam. Including, but not limited to, polyhexamethylene adipamide (PA66), polycaprolactam (PA6), polysebacyldiamine (PA610), polysebacic acid diamine (PA1010), adipic acid-hexane Amine-caprolactam copolymer (PA66/6), polyundecanolactam (PA11), polydodelactam (PA12), and mixtures of two or more thereof.

The ethylene-α-olefin copolymer is preferably an EP elastomer and/or an EPDM elastomer (ethylene-propylene rubber and ethylene-propylene-diene rubber, respectively). For example, the elastomer may include an elastomer based on an ethylene-C3-C12-α-olefin copolymer containing 20% by weight to 96% by weight, preferably 25% by weight to 85% by weight of ethylene, wherein C3-C12-α- is particularly preferred herein. The olefin includes an olefin selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and/or 1-dodecene, and particularly preferably other polymers including ethylene-propylene. One or several of rubber, LLDPE, VLDPE.

Alternatively or additionally (for example in a mixture), the further polymer may further comprise a terpolymer based on an ethylene-C3-C12-α-olefin and a non-conjugated diene, preferably containing 25 wt% to 85 wt% of ethylene and up to 10 wt% of a non-conjugated diene, and particularly preferably, the C3-C12-α-olefin includes a olefin, 1-butene, 1-pentene, 1-hexene An olefin of 1-octene, 1-decene and/or 1-dodecene, and/or wherein the non-conjugated diene is preferably selected from the group consisting of bicyclo [2.2.1] heptadiene, 1,4-hexyl Diene, dicyclopentadiene and/or especially 5-ethylidene norbornene.

Ethylene-acrylate copolymers can also be used as components of the other polymers.

Other possible forms of the other polymers are ethylene-butene copolymers and mixtures (blends) comprising these systems.

Preferably, the other polymer comprises a component having an anhydride group by thermal reaction of the backbone polymer with an unsaturated dianhydride, with an unsaturated dicarboxylic acid, or with a monoalkyl ester of an unsaturated dicarboxylic acid. Or a free radical reaction, introduced at a concentration sufficient to bind well to the polyamide, and it is preferred here to use an agent selected from the group consisting of:

Maleic acid, maleic anhydride, monobutyl maleate, fumaric acid, aconitic acid and/or itaconic anhydride. Preferably, 0.1% by weight to 4.0% by weight of the unsaturated acid anhydride is grafted onto the impact-resistant component as a component of C, or the unsaturated dianhydride or its precursor is applied by grafting together with other unsaturated monomers. It is generally preferred that the degree of grafting is from 0.1% to 1.0%, particularly preferably from 0.3% to 0.7%. Another possible component of other polymers is a mixture of an ethylene-propylene copolymer and an ethylene-butene copolymer, where the degree of grafting of the maleic anhydride (MA grafting degree) is from 0.3% to 0.7%.

The above possible systems for the other polymers can also be used in the form of a mixture.

Further, the additive component may comprise a component having a functional group such as a carboxylic acid group, an ester group, an epoxy group, an oxazoline group, a carbodiimide group, an isocyanate group. The silanol group, and the carboxylate group, or the additive component may comprise a combination of two or more of the above functional groups. The monomer having the functional group may be bonded by copolymerization or grafting onto the elastomeric polyolefin.

Further, the impact modifier based on an olefin polymer can also be modified by grafting with an unsaturated silane compound such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyl Triacetylsilane, methacryloxypropyltrimethoxysilane, or propylenetrimethoxysilane.

An elastomeric polyolefin is a random, alternating or block copolymer having a linear, branched or core-shell structure and contains functional groups which are reactive with the terminal groups of the polyamide, thereby being used in polyamides and impact modifiers. Provide sufficient compatibility between the two.

Thus, the impact modifiers of the present invention include homopolymers or copolymers of olefins (e.g., ethylene, propylene, 1-butene) (e.g., polybutene-1), or olefins and copolymerizable monomers (e.g., vinyl acetate). a copolymer of (meth) acrylate, and methyl hexadiene).

Examples of crystalline olefin polymers are low density, medium density and high density polyethylene, polypropylene, polybutadiene, poly-4-methylpentene, ethylene-propylene block copolymer, or ethylene-propylene random Copolymer, ethylene-methylhexadiene copolymer, propylene-methylhexadiene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene-hexene copolymer, ethylene-propylene-methylhexadiene Copolymer, poly(ethylene-vinyl acetate) (EVA), poly(ethylene-ethyl acrylate) (EEA), ethylene-octene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene- A propylene-diene terpolymer, and a combination of the above polymers.

Examples of commercially available impact modifiers that can be used in the additive component are:

TAFMER MC201: Blend of g-MA (-0.6%) 67% EP copolymer (20 mol% propylene) + 33% EB copolymer (15 mol% 1-butene)): Mitsui Chemicals, Japan.

TAFMER MH5010: g-MA (-0.6%) ethylene-butene copolymer; Mitsui.

TAFMER MH7010: g-MA (-0.7%) ethylene-butene copolymer; Mitsui.

TAFMER MH7020: g-MA (-0.7%) EP copolymer; Mitsui.

EXXELOR VA1801: g-MA (-0.7%) EP copolymer; Exxon Mobile Chemicals, US.

EXXELOR VA1803: g-MA (0.5-0.9%) EP copolymer, amorphous, Exxon.

EXXELOR VA1810: g-MA (-0.5%) EP copolymer, Exxon.

EXXELOR MDEX 941l: g-MA (0.7%) EPDM, Exxon.

FUSABOND MN493D: g-MA (-0.5%) ethylene-octene copolymer, DuPont, US.

FUSABOND A EB560D: (g-MA) ethylene-n-butyl acrylate copolymer, DuPont ELVALOY, DuPont.

Preference is also given to ionic polymers in which the polymer-bonded carboxyl groups are all bonded or bonded to each other by metal ions.

Particularly preferred are copolymers of maleic anhydride graft functionalized butadiene and styrene, non-polar or polar olefin homopolymers and copolymers prepared by grafting with maleic anhydride, and carboxylic acid functionalized a copolymer, such as poly(ethylene-co-(meth)acrylic acid) or poly(ethylene-co-1-olefin-co-(meth)acrylic acid), wherein the acid group has been to some extent by metal ions with.

Further, various processing aids such as an antioxidant and/or a heat-resistant stabilizer (hindered phenol type, hydroquinone type, etc.) may be added to the polyamide resin of the present invention at any time within the range not impairing the effects of the present invention. Phosphite esters and their substituents, copper halides, iodine compounds, etc., and weathering agents (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.) , mold release agents and lubricants (aliphatic alcohols, aliphatic amides, aliphatic bisamides, diureas and polyethylene waxes, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), dyes (nigrosine, Aniline black, etc.), plasticizer (octyl p-hydroxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agent (alkyl sulfate type anionic antistatic agent, quaternary ammonium salt type cationic antistatic agent) , non-ionic antistatic agents such as polyoxyethylene sorbitan monostearate, betained amphoteric antistatic agents, etc.).

In order to obtain the molded article of the present invention, the polyamide resin or the polyamide resin composition of the present invention may be molded by any molding method such as injection molding, extrusion molding, blow molding, vacuum molding, melt spinning, or film molding. These molded articles can be molded into a desired shape, and can be used in resin molded articles such as automobile parts and machine parts. As a specific use, it is useful in the following applications: radiator parts for automobile engines, especially radiator tank components such as the top and bottom of radiator tanks, coolant reserve tanks, water pipes, water pump casings, pump impellers, valves, etc. Components used in contact with cooling water in the engine room of a car, such as switches, subminiature slide switches, DIP switches, housings for switches, lamp holders, straps, connectors, connector housings, connector housings , IC sockets, bobbins, spool covers, relays, relay boxes, capacitor housings, internal parts of motors, small motor housings, gear cams, equalizing wheels, gaskets, insulators, fasteners, buckles, clamps, Bicycle wheels, casters, helmets, terminal blocks, housings for power tools, insulation for starters, spoilers, tanks, radiator tanks, chamber tanks, liquid storage tanks, fuse boxes, air purifiers Housing, air conditioning fan, terminal housing, wheel cover, suction and exhaust pipe, bearing support, cylinder head cover, intake manifold, water pipe impeller Clutch separation lever, speaker diaphragm, heat-resistant container, microwave oven parts, rice cooker parts, printer ribbon guides, etc. Electrical/electronic related parts, automotive/vehicle related parts, home appliances/office electrical parts, computer related parts, fax Machine/copier related parts, mechanical related parts, and other various uses.

Compared with the prior art, the invention has the following beneficial effects:

By adding a certain amount of PA6I homopolymer to the PA6T homopolymer, the invention can significantly reduce the melting point of the PA6T homopolymer to below the decomposition temperature, thereby improving the processing property of the PA6T homopolymer, and preparing the semi-aromatic poly The amide resin has a lowered melting point and can be processed normally, and the polyamide molding composition composed of the semi-aromatic polyamide resin has good processability and excellent surface characteristics.

detailed description

The invention is further illustrated by the following detailed description of the preferred embodiments of the invention, but the embodiments of the invention are not limited by the following examples.

Synthesis of PA6T homopolymer:

In an autoclave equipped with a magnetic coupling stirring, a condenser, a gas phase port, a feed port, and a pressure explosion port, 400 g (3.44 mol) of hexamethylenediamine, 548 g (3.30 mol) of terephthalic acid, and 11.3 g (0.09 mol) of benzene were placed. Formic acid, 1.0 g of sodium hypophosphite and 410 g of water. The mixture was purged with high-purity nitrogen gas as a shielding gas, and the temperature was raised to 220 ° C over 2 hours with stirring. The reaction mixture was stirred at 220 ° C for 1 hour, and then the temperature of the reactant was raised to 250 ° C with stirring. The reaction was continued at a constant temperature of 250 ° C and a constant pressure of 3.6 MPa for 2 hours, and the pressure was kept constant by removing the formed water. After the completion of the reaction, the prepolymer was dried under vacuum at 80 ° C for 24 hours to obtain a prepolymerized product. The prepolymerized product was solid phase viscosified at 290 ° C under a vacuum of 50 Pa to obtain a PA6T homopolymer. Its melting point is 370 ° C, the relative viscosity of 2.33.

PA6I homopolymer was purchased from Shandong Weifang Xianglong New Material Co., Ltd.;

Other materials used in the present invention are derived from commercially available products.

Performance test method:

Test method for melting point of semi-aromatic polyamide resin: refer to ASTM D3418-2003; specific test method is: test the melting point of the sample using a Perkin Elmer Dimond DSC analyzer; nitrogen atmosphere, flow rate is 40 mL / min; test at 10 ° C first /min was heated to 340 ° C, held at 340 ° C for 2 min, then cooled to 50 ° C at 10 ° C / min, and then heated to 340 ° C at 10 ° C / min, the endothermic peak temperature at this time as the melting point T _m ;

The surface characteristics of the molded articles of the polyamide molding composition are characterized by surface roughness Ra, and the tests are carried out in accordance with the National Standard GB 10610-89 "Rules and Methods for Measuring Surface Roughness by Stylus Instruments". The specific steps are: injection molding the sample into a piece of 100 mm × 100 mm × 2 mm. The surface roughness value R _{a was} measured using a JB-6C stylus type roughness meter manufactured by Guangzhou Guangzhuo Measuring Instrument Co., Ltd. The larger the _Ra , the rougher the surface.

Test method for water absorption rate: The sample was injection molded into a 20 mm × 20 mm × 2 mm part, and its weight was recorded as a0. Then, after placing it in water at 95 ° C for 240 h, the weight was weighed as a1. Then, the water absorption rate = (a1 - a0) / a0 * 100%.

Preparation of semi-aromatic polyamide resins A-G and A'

The PA6I homopolymer and the PA6T homopolymer were uniformly mixed in a high-mixing machine according to the ratio of Table 1, and then pulverized into a powder of 5-10 um in an AB10 type jet mill produced by Weifang City Essence Powder Engineering Equipment Co., Ltd.; The powder was introduced into a twin-screw extruder through a main feed port, extruded, cooled with water, granulated and dried to obtain a semi-aromatic polyamide resin. The melting points of the obtained semi-aromatic polyamide resin are shown in Table 1.

Table 1:

	Resin A	Resin B	Resin C	Resin D	Resin E	Resin F	Resin G	Resin A'
PA6T homopolymer / wt%	5	30	50	60	70	80	15	95
PA6I homopolymer / wt%	95	70	50	40	30	20	85	5
Melting point / °C	-	-	262	293	322	334	-	358

It can be seen from Table 1 that in the resins A, B and G, the PA6I has a high content of random structure and no melting point; in the resin CF, by adding a certain amount of PA6I homopolymer to the PA6T homopolymer, the PA6T can be significantly lowered. When the melting point of the homopolymer is below the decomposition temperature, the prepared semi-aromatic polyamide resin has a lower melting point and can be processed normally; the resin A' is too high in the PA6T homopolymer content, and is close to the decomposition temperature, making it difficult to process normally.

Examples 1-8 and Comparative Examples 1-2: Preparation of Polyamide Molding Compositions

According to the formulation of Table 2, the semi-aromatic polyamide resin, reinforcing filler and additive were uniformly mixed in a high-mixer, and then fed into the twin-screw extruder through the main feed port, and the reinforcing filler was fed side by side feeding scale. The polyamide composition is obtained by extrusion, cooling with water, granulation and drying. The performance results are shown in Table 2.

Table 2 Component and performance test results of polyamide molding composition (parts by weight)

As can be seen from Table 2, the polyamide molding composition comprising the semi-aromatic polyamide resin of the present invention has good processability and excellent surface characteristics under the same molding composition formulation. The pure PA6T melting point is higher than the decomposition temperature and cannot be processed; the resin A' is too high in PA6T content, close to the decomposition temperature, and a large amount of small molecular gas escapes during melting, resulting in a very rough surface and poor surface properties.

Claims (10)

1. A semi-aromatic polyamide resin characterized by, by weight percent, consisting of the following components:

   (A) 20-95% by weight of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

   (B) 5-80% by weight of a PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

   Among them, (A) + (B) = 100% by weight.
2. The semi-aromatic polyamide resin according to claim 1, which is composed of the following components in terms of percentage by weight:

   (A) 30-85 wt% of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

   (B) 15-70% by weight of a PA 6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

   Among them, (A) + (B) = 100% by weight.
3. The semi-aromatic polyamide resin according to claim 2, which is composed of the following components in terms of percentage by weight:

   (A) 40-70% by weight of a PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid;

   (B) 30-60% by weight of a PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid;

   Among them, (A) + (B) = 100% by weight.
4. The semi-aromatic polyamide resin according to any one of claims 1 to 3, wherein the semi-aromatic polyamide resin has a melting point of 240 to 340 ° C with reference to ASTM D3418-2003.
5. The semi-aromatic polyamide resin according to any one of claims 1 to 3, wherein the semi-aromatic polyamide resin is amorphous, microcrystalline or amorphous.
6. The method for preparing a semi-aromatic polyamide resin according to any one of claims 1 to 5, comprising the steps of:

   The PA6T homopolymer derived from 1,6-hexanediamine and terephthalic acid and the PA6I homopolymer derived from 1,6-hexanediamine and isophthalic acid are uniformly mixed in a high-mixer. It is pulverized into a powder of 5-10 um in a pulverizer; the powder is introduced into a twin-screw extruder through a main feed port, extruded, cooled by water, granulated and dried to obtain a semi-aromatic polyamide resin.
7. A polyamide molding composition comprising the semi-aromatic polyamide resin according to any one of claims 1 to 5, in parts by weight, comprising the following components:

   Semi-aromatic polyamide resin 30-100 parts;

   Reinforcing filler 0-70 parts;

   Additive 0-50 parts.
8. The polyamide molding composition according to claim 7, wherein the reinforcing filler has a fibrous shape having an average length of from 0.01 mm to 20 mm, preferably from 0.1 mm to 6 mm; and an aspect ratio of 5 : 1-2000: 1, preferably 30: 1-600: 1; The reinforcing filler is contained in an amount of 10 to 50 parts, preferably 15 parts to 40 parts, based on the total weight of the polyamide molding composition; the reinforcing filler is an inorganic reinforcing filler or an organic reinforcing filler, and the inorganic reinforcing filler is selected From glass fiber, potassium titanate fiber, metal clad glass fiber, ceramic fiber, wollastonite fiber, metal carbide fiber, metal curable fiber, asbestos fiber, alumina fiber, silicon carbide fiber, gypsum fiber or boron fiber One or more, preferably glass fibers; the organic reinforcing filler is selected from the group consisting of aramid fibers and/or carbon fibers.
9. The polyamide molding composition according to claim 7, wherein the reinforcing filler has a non-fibrous shape and has an average particle diameter of from 0.001 μm to 100 μm, preferably from 0.01 μm to 50 μm, selected from the group consisting of titanic acid. Potassium whiskers, zinc oxide whiskers, aluminum borate whiskers, wollastonite, zeolites, sericite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, hectorite, synthetic mica, asbestos, silicon Aluminate, alumina, silica, magnesia, zirconia, titania, iron oxide, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass One or more of beads, ceramic beads, boron nitride, silicon carbide or silicon dioxide.
10. The polyamide molding composition according to claim 7, wherein the additive is selected from one or more of a flame retardant, an impact modifier, another polymer, and a processing aid; The flammable agent is a halogen-based flame retardant or a halogen-free flame retardant, preferably a halogen-free flame retardant; the other polymer is an aliphatic polyamide, a polyolefin homopolymer, an ethylene-α-olefin copolymer or an ethylene-acrylic acid. One or more of the ester copolymers.