Polyamide molding compound for manufacturing components with high weld line strength
Patent Information
- Application Number
- JP2026512274
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-31
- Filing Date
- 2024-08-23
- Publication Date
- 2026-09-09
Smart Images
Figure 2026530612000001_ABST
Abstract
Description
[[Technical Field]]
[0001] The present invention relates to a polyamide molding compound for producing members having high weld line strength, to members produced using such a polyamide molding compound, to a method for producing such a polyamide molding compound, and to a method for producing members from such a polyamide molding compound. [[Background Art]]
[0002] Polyamide-based members, such as fiber-reinforced injection-molded parts, are increasingly used, for example, as components in the automotive industry. They are being replaced for metal members in particular because they not only have advantages over metal members due to their lower specific gravity, but also their mechanical and thermal properties can be adapted to the respective loads applied to the member by incorporating various components. Filled plastics are used for such members. Molding compounds contain thermoplastics and fillers. Fillers of any shape can be used, for example elongated or spherical particles. An important example of such filled plastics is fiber-reinforced molding compounds, which contain thermoplastics and are reinforced with fibers, particularly glass fibers. When such molding compounds are injected into injection molds in a molten state or molten flow, the fillers are oriented and / or unevenly distributed within the plastic matrix. This is caused, in particular, by strong shear and strain flows, which cause alignment or separation of filler particles. This results in anisotropic properties of the component, for example, with respect to its strength, stiffness, shrinkage, or even thermal conductivity and expansion. Anisotropic shrinkage is, in turn, the main cause of warping of the component, as is often seen in fiber-reinforced injection-molded parts. Particularly pronounced anisotropy occurs in the shadow of flow obstructions. Bind seams or weld lines are unavoidable in many molds in injection molding technology, and these also form fiber orientations parallel to the course of the bind seams, resulting in these areas exhibiting strength no better than unreinforced or unfilled matrix material when subjected to stress perpendicular to the bind seams. Static weld lines and dynamic weld lines are fundamentally distinguished. Static weld lines occur, for example, in the welding process when joining thermoplastic molded parts. Dynamic weld lines occur in plastic members during the injection molding process, for example, due to the confluence of at least two mass flows behind a cavity, due to differences in wall thickness, or due to multiple gates or injection points in the mold. When two flow fronts meet, a weld line, also called a bind seam, weld seam, or flow line, is formed at the confluence point. Visually, these seams appear as lines. Therefore, weld lines are a frequently visible surface effect on injection molded parts.
[0003] Weld lines are potential weak points in a component. Flow fronts typically meet perpendicularly due to volume expansion and weld to each other. The lower the pressure and temperature, the weaker the weld line. Reinforcement fibers often orient themselves parallel to the weld line due to the shear forces and flow conditions acting during the injection molding process. When the melt has cooled significantly and the melt fronts meeting can no longer completely weld together, the weld line often appears as a V-shaped notch on the surface. If tensile stress occurs in this area, the notch effect causes increased stress at the weld line, and the weld line then acts as a predetermined fracture point. International Publication No. 2010 / 014801 describes the manufacture of heat-resistant polyamide molded articles, in which polyhydric alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, di-trimethylolpropane, D-mannitol, D-sorbitol, or xylitol are added to the polyamide. Polyamide mixtures can also be used. According to embodiments, the polyamide mixture contains a larger proportion of at least partially aromatic polyamide and a smaller proportion of aliphatic polyamide. International Publication No. 2011 / 94553 describes corresponding polyhydroxypolymers for equivalent applications.
[0004] European Patent No. 2307480 relates to a heat-resistant thermoplastic article having a co-stabilizer. The article is made from a polyamide composition containing at least one polyhydric alcohol having more than two hydroxyl groups and a number-average molecular weight (Mn) of less than 2,000, and a co-stabilizer selected from secondary arylamines and hindered amine light stabilizers (HALS) and mixtures thereof. The polyamide resin also contains a reinforcing agent. International Publication No. 2015 / 022404 describes a method for producing a thermoplastic molding composition having improved bond seam strength while maintaining mechanical strength compared to known fiber-reinforced thermoplastic molding compositions, the method comprising the steps of: melting a first granular material containing at least one thermoplastic polymer A1 and at least one fibrous reinforcing material B2 having an average fiber length of 4.5 to 13.0 mm; adding a second granular material containing at least one thermoplastic polymer A2 and at least one fibrous reinforcing material B1 having an average fiber length of 0.15 to 4.2 mm; or melting a mixture containing a first granular material containing at least one thermoplastic polymer A1 and at least one fibrous reinforcing material B2 having an average fiber length of 4.5 to 13.0 mm, and a second granular material containing at least one thermoplastic polymer A2 and at least one fibrous reinforcing material B1 having an average fiber length of 0.15 to 1.2 mm.
[0005] International Publication No. 2019 / 149791 describes using a polyhydric alcohol having more than two hydroxyl groups in a polyamide composition containing at least one polyamide to improve the weld line strength after thermal aging of molded articles produced from polyamide compositions by injection molding, wherein at least two flow fronts of the molten polyamide composition meet during injection molding to form at least one weld line. International Publication No. 2020 / 173766 describes, in connection with this, the use of glass fibers having a tensile strength of 86.0–92.0 GPa according to DIN ISO 527-5, a tensile modulus of 2600–3200 MPa according to DIN ISO 527-5, and a softening point of 900–950°C according to DIN ISO 7884-1 in order to improve the weld line strength of molded articles made from molding compounds containing thermoplastic polyamide. European Patent No. 1728615 describes a method for counteracting the orientation and / or distribution of fillers in a molding compound made of filler plastic in an injection-molded part. Such a method is particularly necessary in injection molding and can stabilize weld lines. The method is characterized by exposing the injection mold and the molding compound to sound during injection molding within the injection mold. The sound has frequencies within the spectrum of the first 10 natural frequencies of the filler-matrix system. By exposing the fillers in the injection molding compound, such as fibers, to a more isotropic distribution with respect to their orientation and distribution, resulting in significantly improved mechanical and optical properties of the injection-molded part.
[0006] European Patent No. 0346825 describes a molding composition comprising a polyamide or a resin mixture of a polyamide resin and a monomer having a vinyl group, and an inorganic filler consisting of a glass filler and calcium carbonate. International Publication No. 2018 / 060270 describes a polymer composition comprising (A) at least (A-1) a first semicrystalline semi-aromatic polyamide (SSPA) and (A-2) a functionalized polymer; (B) 5 to 69% by mass of a reinforcing agent; and (C) 0 to 25% by mass of one or more other components; the SSPA is present in an amount ranging from 30 to 90% by mass; has a melting point (Tm) of at least 300°C; and comprises (A-1-a) (i) aromatic dicarboxylic acid and (ii) 90 to 100 mol% repeating units derived from diamines, and (A-1-b (A) consists of 0-10 mol% repeating units derived from other monomers; (B) consists of 80-95 mol% linear aliphatic diamine, 5-20 mol% 2-methylpentamethylenediamine, and 0-10 mol% other diamines; the functionalized polymer (A-2) contains 1-15% by mass of functionalized semicrystalline polyolefin, and the mass percentages (mass%) of components (A), (B), and (C), as well as SSPA and functionalized semicrystalline polyolefin, are based on the total mass of the composition, while the sum of (A), (B), and (C) is 100% by mass.
[0007] European Patent No. 3330319 describes a mixture having a dielectric constant of 3.5 or less at 2.45 GHz, comprising the following components: (A) Aa) 50.1 to 90 mass% of at least one semicrystalline, aliphatic polyamide and Ab) 10 to 49.9 mass% of at least one amorphous or microcrystalline polyamide, in a mixture of 25 to 80 mass% (where the proportions of components Aa) and Ab) totaling 100 mass%, and the mixture of components Aa) and Ab) having an average of at least 5 per amide group of mixture (A) that are not involved in the amide group. The present invention describes a polyamide molding compound comprising (A) a glass composition selected from the group consisting of (B) fibers, crushed fibers, particles, flakes, spherical objects, and mixtures thereof, with a glass composition having a content of 0 to 12% by mass of alkali oxides and alkaline earth oxides, and (C) 0 to 10% by mass of additives, wherein the total of components (A), (B), and (C) is 100% by mass.
[0008] European Patent No. 3156435 describes copolyamides formed from a diamine component, a dicarboxylic acid component, and optionally a lactam and / or ω-amino acid component. Furthermore, this invention relates to polyamide molding compounds containing at least one of these copolyamides. Molded articles produced from these molding compounds are used in the automotive sector, the household goods sector, in measurement, control and adjustment technologies, or in mechanical engineering. International Publication No. 2015 / 071281 relates to a polyamide molding composition, particularly a polyamide molding composition for producing heat-resistant molded members, comprising the following composition: (A) 20 to 79 mass% of at least one partially aromatic polyamide in the form of a copolyamide having 50 to 80 mol.% units formed from hexanediamine and terephthalic acid; (B) 1 to 15 mass% of at least one impact-resistant modifier; (C) 20 to 60 mass% of at least one carbon fiber; and (D) 0 to 5 mass% of at least one additive, with components (A) to (D) totaling 100 mass%. This document clearly discloses erroneous information regarding the composition of sizing for Vetrotex 995 EC10-4.5 type glass fibers.
[0009] European Patent No. 2927263 relates to a material comprising the following components: (A) (a1) 65-82 mol% terephthalic acid based on the total dicarboxylic acid used; (a2) 18-35 mol% isophthalic acid based on the total dicarboxylic acid used; (a3) 1,6-diaminohexane; (a4) at least one monofunctional carboxylic acid; and (a5) 25-74.9 mass% of at least one semicrystalline, semi-aromatic polyamide 6T / 6I formed from a phosphorus compound (provided, as a first condition, that the molar ratio of component (a3) to the total dicarboxylic acid used ((a1) + (a2)) is at least 1.04. The following describes a polyamide molding compound, particularly for use in components for the drinking water sector, comprising: (B) 25-60% by mass of fibrous reinforcing material; (C) 0-30% by mass of particulate filler; (D) 0.1-2.0% by mass of heat stabilizer (except copper-containing stabilizers); (E) 0-2% by mass of carbon black; and (F) 0-4% by mass of auxiliary materials and / or additives other than C, D, and E, with the total of components (A) to (E) being 100% by mass.
[0010] International Publication No. 2018 / 011131 describes a polyamide molding compound comprising the following components: (A) 35-68% by mass of at least one semicrystalline, semi-aromatic, thermoplastic polyamide based on an aliphatic diamine having 4-8 carbon atoms and a melting point of at least 270°C; (B) 15-22% by mass of carbon fibers; (C) 18-30% by mass of glass fibers; (D) 1-10% by mass of an impact modifier different from (E) and / or a polymer different from (A), (E), and (F); (E) 0-10% by mass of ethylene-vinyl acetate copolymer; and (F) 0-3% by mass of additives. The total of components (A)-(F) is 100% by mass, the total of components (B)-(C) is in the range of 33-48% by mass, and the total of components (D)-(E) is in the range of 2-12% by mass. Molding compounds enable the manufacture of dimensionally stable, conductive components for applications such as the automotive sector and for contact with fuels, particularly methanol-containing gasoline. [Overview of the project]
[0011] The object of the present invention is to provide a polyamide molding compound having good mechanical properties, in particular preferably good thermomechanical properties, which can be processed well by injection molding, and in particular has good weld line strength, which is preferably high not only immediately after manufacture but also after exposure to chemicals. Preferably, molded articles produced by injection molding from the proposed polyamide molding compound also exhibit good mechanical properties even after long-term chemical aging and / or thermal aging at high temperatures. The object of the present invention is to provide a polyamide composition suitable for the production of injection molded articles that exhibit improved weld line strength after thermal aging. Therefore, the present invention relates particularly to thermoplastic polyamide molding compounds as defined in claim 1.
[0012] Specifically, the present invention relates to a thermoplastic polyamide molding compound comprising the following components: (A) 37-75% by mass or 30-74.5% by mass of at least one semicrystalline, semi-aromatic copolyamide 6T / Z having a melting point of at least 270°C, The polyamide unit Z is composed of at least one lactam or one aminocarboxylic acid, and / or a different block from 6T, consisting of at least one diamine and at least one dicarboxylic acid. In 6T / Z, the content of 6T exceeds 50 mol% based on the molar percentage of all polyamide units. Semicrystalline, semi-aromatic copolyamide 6T / Z, (B) Glass fibers having an average diameter of 5 to 8 μm or 5 to 7 μm, comprising 25 to 45% by mass or 25 to 50% by mass. (b1) At least one silane compound, (b2) at least one polymer or copolymer based on an unsaturated carboxylic acid and / or an anhydride of an unsaturated carboxylic acid, (b3) at least one epoxy, polyurethane, or polyamide resin It is coated with a sizing composition (b) which includes, However, if component (b3) is a system containing a carboxylic acid and / or a carboxylic acid anhydride, the sizing composition does not need to contain component (b2). Glass fiber and, (C) 0-8% by mass or 0.5-8% by mass of an impact resistance modifier, (E) 0-20% by mass of amorphous partially aromatic polyamide, (D) Additives other than (A)~(C) and (E) in amounts of 0 to 10% by mass and It consists of, The sum of the amounts of components (A) to (E) equals 100% by mass of the polyamide molding compound. Regarding thermoplastic polyamide molding compounds.
[0013] For the purposes of this invention, the term “polyamide” (abbreviated PA) is understood to be a general term including homopolyamides and copolyamides. The spellings and abbreviations selected for polyamides and their monomers correspond to those specified in ISO standard 1874-1 (2011, (D)). The abbreviations used herein are used below as synonyms for the IUPAC names of the monomers; in particular, the following abbreviations exist for the monomers: T for terephthalic acid (CAS number 100-21-0), I for isophthalic acid (CAS number 121-95-5), BAC for bis(aminomethyl)cyclohexane, including 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 1,4-bis(aminomethyl)cyclohexane (1,4-BAC). 6T represents a polyamide unit composed of 1,6-hexamethylenediamine and terephthalic acid. According to the first preferred embodiment, the polyamide molding composition has a Z of component (A) It is composed of polyamide units derived from at least one lactam or aminocarboxylic acid having at least 4, preferably 5 to 12, carbon atoms, wherein the lactam and / or aminocarboxylic acid are preferably selected as aliphatic linear systems. Furthermore, and / or, Z is composed of polyamide units other than 6T of at least one diamine having 5 to 12 carbon atoms and at least one dicarboxylic acid having 5 to 12 carbon atoms, wherein the diamine is preferably selected as an aliphatic linear or cyclic diamine, and more preferably the dicarboxylic acid is selected as an aliphatic linear dicarboxylic acid. It is characterized by the following:
[0014] The following monomers are suitable as diamines, for example: 1,4-butanediamine, 1,5-pentanediamine, 2-methyl-1,5-pentanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,6-hexanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,8-octanediamine, 2-methyl-1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, m-xylylenediamine, and p-xylylenediamine; 1,6-hexanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane are preferred.
[0015] The following monomers can be used as dicarboxylic acids, for example: adipic acid, cork acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, C36 dimer fatty acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, cis- and / or trans-cyclohexane-1,4-dicarboxylic acid, and / or cis- and / or trans-cyclohexane-1,3-dicarboxylic acid (CHDA), and mixtures thereof. Adipic acid, isophthalic acid, sebacic acid, and dodecanedioic acid are preferred. Further, the polyamide may also contain a lactam or an aminocarboxylic acid, in particular an α,ω-amino acid having 6 to 12 carbon atoms or a lactam, examples of which are listed below: m-aminobenzoic acid, p-aminobenzoic acid caprolactam (CL), α,ω-aminocaproic acid, α,ω-aminoheptanoic acid, α,ω-aminooctanoic acid, α,ω-aminononanoic acid, α,ω-aminodecanoic acid, α,ω-aminoundecanoic acid (AUA), laurolactam (LL), and α,ω-aminododecanoic acid (ADA). Caprolactam, ω-aminocaproic acid, α,ω-aminoundecanoic acid, laurolactam, and α,ω-aminododecanoic acid are particularly preferred.
[0016] Copolyamide 6T / Z may be selected from the group consisting of 6T / 6I, 6T / DT, 6T / BACT, 6T / 66, 6T / 610, 6T / 612, 6T / 6I / 66, 6T / 6I / 6, 6T / 6I / 610, 6T / 6I / 612, or mixtures thereof, preferably the proportion of polyamide units other than 6T, in particular 6I, DT, 66, 610, 612, or BACT is more than 20%, and the described copolyamide may further comprise a polyamide unit XY selected from the group consisting of 56, 66, 610, 612, BACI, BAC6, BAC10, and BAC12 in a proportion of less than 30 mol%. It is particularly preferred when copolyamide 6T / Z is selected as 6T / 6I, with a proportion of 6T blocks in the range of 60 to 80 mol%, preferably 65 to 75 mol%. Particularly preferably, copolyamide 6T / Z in the form of 6T / 6I preferably has a melting point above 300°C, particularly preferably at least 310°C, very particularly preferably in the range of 320°C to 330°C. Within the meaning of the present application, melting points are measured on granular materials in accordance with ISO 11357-3 (2018), as specified in more detail below.
[0017] Copolyamide 6T / Z further or alternatively has a relative viscosity in the range of 1.3 to 1.8, particularly preferably in the range of 1.5 to 1.75, and especially preferably in the range of 1.6 to 1.7, as measured under the conditions and concentrations specified in the experimental description. The following applies to the proportions within the polyamide molding compound: The proportion of component (A) is in the range of 37 to 74.5 mass percent or 42 to 70 mass percent, preferably in the range of 48 to 64.4 mass percent. and / or the proportion of component (B) is in the range of 30 to 45 mass percent, preferably in the range of 35 to 42 mass percent. and / or the proportion of component (C) is in the range of 0 to 6 mass percent, or 0.5 to 6 mass percent, or 0.5 to 5 mass percent, preferably in the range of 0.7 to 5.0 mass percent, or 0.7 to 3.5 mass percent, or preferably in the range of 0.5 to 5 mass percent. and / or the proportion of component (E) is in the range of 5 to 20 mass percent, preferably in the range of 6 to 16 mass percent. and / or the proportion of component (D) is in the range of 0 to 7 mass percent, preferably in the range of 0.1 to 5.0 mass percent. The sum of components (A) to (E) equals 100 mass percent of the polyamide molding compound.
[0018] The glass fibers of component (B) preferably have a length in the range of 2 to 7 mm, more preferably in the range of 3 to 5 mm, which is the length of the starting material. Preferably, the glass fibers of component (B) have an average diameter (arithmetic mean) in the range of 5 to 8 μm, preferably in the range of 6 to 7 μm. The glass fibers of component (B) are preferably E-glass fibers (E = electric) and / or have a round cross-section. According to ASTM D578-00, E-glass fibers consist of 52-62% silicon dioxide and 12-16% aluminum oxide. For better compatibility with a thermoplastic matrix, the glass fibers (B) are coated with a sizing composition (b) containing at least one silane compound (b1), at least one polymer or copolymer (b2) based on an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride, and an epoxy, polyurethane, or polyamide resin (b3).
[0019] The sizing composition (b) is used in an amount preferably 0.2 to 2.0% by mass, particularly preferably 0.3 to 1.5% by mass, and especially 0.4 to 1.2% by mass, in each case specified as the dry mass based on component (B) for surface coating. Ingredient (b1): Preferred silane compounds include trialkoxysilane, dialkoxysilane, epoxysilane, vinylsilane, (meth)acrylooxysilane, aminosilane, and mercaptosilane.
[0020] Appropriate representative examples of these silane compounds include, for example, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ-(meth)acrylooxypropylmethyldimethoxysilane, γ-(meth)acrylooxypropylmethyldiethoxysilane, ((meth)acrylooxymethyl)methyldimethoxysilane, γ-(meth)acrylooxypropyltrimethoxysilane, γ-(meth)acrylooxypropyltri Ethoxysilane, (meth)acrylooxypropyldimethylmethoxysilane, (meth)acrylooxypropyldimethylethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminoisobutylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyl Ludiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminoisobutylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, These are γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, bis-(γ-trimethoxysilylpropyl)amine, N-phenyl-γ-aminopropyltrimethoxysilane, γ-amino-3,3-dimethylbutyltrimethoxysilane, γ-aminobutyltriethoxysilane, and polyazamidsilane.
[0021] Furthermore, suitable silane compounds have a general formula (X-(CH2) n ) k -Si-(OC m H 2m+1 ) 4-k It is a compound of the form, and the substituents in the formula have the following meanings: X:NH2-, HO-, epoxy n: an integer between 2 and 10, preferably between 3 and 4. m: an integer between 1 and 2, preferably between 1 and 2. k: an integer between 1 and 3, preferably 1. Particularly preferred silane compounds are primary and secondary aminosilane compounds, such as aminopropyltrimethoxysilane, aminobutyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyltriethoxysilane, bis(3-triethoxysilylpropyl)amine, and N-[3-(trimethoxysilyl)-propyl]ethylenediamine. Particularly preferred silane compounds are aminoalkyltrialkoxysilanes, preferably aminopropyltriethoxysilane or aminopropyltrimethoxysilane.
[0022] The silane compound (b1) is preferably contained in the dry sizing composition (b) in an amount of 2 to 20% by mass, and particularly preferably 3 to 15% by mass. Ingredient (b2): The sizing agent of the present invention further contains, as component (b2), a homopolymer or copolymer based on an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride or a salt thereof. Preferably, these are polymers and copolymers based on acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, aconitic acid, maleic anhydride, itaconic anhydride, and aconitic anhydride. Particularly preferred are (meth)acrylic acid polymers or copolymers, olefin-maleic anhydride copolymers, or mixtures thereof. Component (b2) is preferably contained in the dry sizing composition (b) in an amount of 1 to 70.0% by mass, particularly preferably 5 to 50% by mass. The unsaturated carboxylic acid is preferably a (meth)acrylic acid monomer having the formula CH2=CX-COOH (wherein X may be a hydrogen atom or a methyl or alkyl group having 1 to 10 carbon atoms). Acrylic acid and methacrylic acid are particularly preferred as unsaturated carboxylic acids. Therefore, polyacrylic acid, polymethacrylic acid, or copolymers containing acrylic acid and methacrylic acid are preferred.
[0023] Preferred unsaturated anhydrides are maleic anhydride, itaconic anhydride, and aconitic anhydride, with maleic anhydride being particularly preferred. Suitable comonomers for unsaturated carboxylic acids and anhydrides are olefins, particularly α-olefins. Preferred comonomers are ethene, propene, butene, isobutene, butadiene, or pentadiene. Preferred copolymers containing acrylic acid or methacrylic acid are ethene-acrylic acid and ethene-methacrylic acid copolymers. Preferred olefin-maleic anhydride copolymers are ethene-maleic anhydride, butadiene-maleic anhydride, buta-1-ene-maleic anhydride, isobutylene-maleic anhydride, and (meth)acrylate-maleic anhydride copolymers. Salts of these homopolymers or copolymers are also preferred. The salts of polyacrylic acid or acrylic acid copolymers may be alkali metal salts or ammonium salts. The degree of neutralization of the polyacrylic acid or acrylic acid copolymer may be 20% to 90% ammonium hydroxide, with a preferred degree of neutralization being 30% to 60%. Generally, ammonium hydroxide is added to the aqueous solution of polyacrylic acid to obtain a pH value of about 5 or higher. Particularly preferred components (b2) are polyacrylic acid or its alkali salts or ammonium salts, and ethylene-maleic anhydride copolymers, or mixtures thereof.
[0024] Alternatively, polymers grafted with acrylic acid or maleic anhydride, particularly polyolefins such as polyethylene, polypropylene, polybutene, polyethylene-co-propylene, or polyethylene-co-butylene, can be used as component (b2). Ingredient (b3): As a further component, the sizing composition (b) also contains at least one epoxy resin, one polyurethane resin, or one polyamide resin as component (b3). Component (b3) is preferably contained in the sizing composition (b) in an amount of 5 to 95% by mass, particularly preferably 10 to 80% by mass. Preferred epoxy resins include bisphenol A or bisphenol F epoxy resin, epoxy ester resin, epoxy urethane resin, epoxy phenol novolac resin (EPN), and epoxy cresol novolac resin (ECN). The polyurethanes used in accordance with the present invention may or may not have crosslinking. In the latter case, they are thermoplastic polyurethanes. Preferably, the polyurethane is a reaction product of an organic polyhydroxy compound, polyether, or polyester diol with a diisocyanate. Preferred diisocyanates are aliphatic diisocyanates such as isophorone diisocyanate, 4,4'-dicyclohexane diisocyanate, or mixtures thereof. Other suitable diisocyanates include, for example, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate, 4,6-xylene diisocyanate, paraphenylene diisocyanate, cyclohexyl diisocyanate, 3,3'-tridol-4,4'-diisocyanate, and 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate.
[0025] Furthermore, polyurethane ionomers containing ionic side groups such as sulfonic acid groups or carboxylic acid groups are suitable. They have the advantage of facilitating the formation of stable aqueous dispersions of polyurethane. Various polyurethane dispersions useful for the present invention include, in particular, aqueous emulsions of blocked polyurethane resins, such as aqueous solutions of polyurethane polymers formed by the reaction of organic isocyanates or polyisocyanates with organic polyhydroxylated compounds or polyethers or polyester polymers having hydroxyl-terminated groups. The polyurethane dispersions may contain crosslinking groups. Another suitable example is chain-extended thermoplastic polyurethane obtained from chain extension of isocyanate-terminated prepolymers produced by the reaction of aliphatic or alicyclic diisocyanates with polyalkylene ether polyols.
[0026] A suitable polyurethane crosslinking agent dispersion is an anionic aliphatic, low-branched polyester polyurethane emulsion containing caprolactam-blocked isocyanates, which cure the polyurethane polymer at temperatures above approximately 150°C. Specifically, a suitable polyurethane crosslinking agent dispersion comprises an aqueous dispersion of a polyester polyol or polyether polyol and a high molecular weight branched polyurethane polymer based on 1,1-methylene-bis-(isocyanate cyclohexane), in which a portion of the polymer chains are terminated with blocked isocyanate groups. Other suitable polyurethane crosslinking agent dispersions include polyurethane / isocyanate emulsions of aliphatic polyurethanes containing blocked isocyanates. Other suitable polyurethane crosslinking agent dispersions include polyurethanes and trimers of 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate ("isophorone diisocyanate" or "IPDI") blocked with butanone oxime. Other blocking groups such as phenol, cresol, caprolactam, malonic acid, acetoacetic acid, and sodium bisulfite may also be used.
[0027] The sizing composition (b) used in the present invention may further contain several additives, such as those listed below as examples. These additives may be present individually or in any combination in addition to components (b1) to (b3) in (b): - pH adjusters, such as bases, preferably ammonia or sodium hydroxide, and acids, preferably acetic acid or phosphoric acid, - Nonionic lubricant, preferably a fatty alcohol or fatty acid monoester of polyethylene glycol (PEG), such as PEG 200 monolaurate, PEG 600 monooleate, PEG 600 monostearate, PEG 400 monostearate, PEG 400 monooleate, PEG 600 monolaurate, etc. - Cationic lubricants, such as polyethyleneimine polyamide salts, - Antistatic agents, such as quaternary ammonium salts, tetraethylammonium chloride, or lithium chloride, - Antifoaming agents, such as polysiloxane derivatives, - Isocyanate-based crosslinking agents, such as isocyanurate, biuret, carbodiimide, etc. - Boron-containing compounds, such as boric acid, boron oxide, sodium tetraborate, potassium metaborate, potassium tetraborate, ammonium diborate, ammonium tetrafluoroborate, or butylammonium tetrafluoroborate, calcium tetrafluoroborate, lithium fluoroborate, potassium tetrafluoroborate, sodium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, and zinc tetrafluoroborate, etc. - Hypophosphorous acid-containing compounds or phosphite-containing compounds, such as sodium hypophosphite, ammonium hypophosphite, calcium hypophosphite, trisnonylphenyl phosphite, etc.
[0028] The impact-improving agent of component (C) is preferably from the following group: natural rubber, polybutadiene, polyisoprene, polyisobutylene; copolymers of butadiene and / or isoprene with styrene or styrene derivatives; hydrogenated copolymers of this type; copolymers formed by grafting or copolymerization with acid anhydrides, (meth)acrylic acid, and their esters; graft rubber having a crosslinked elastomer core made of butadiene, isoprene, and / or alkyl acrylate, and a polystyrene graft shell; ethylene-propylene, ethylene-butylene, ethylene-propylene-diene, and ethylene-octene or ethylene-vinegar Olefin homopolymers and copolymers containing vinyl rubber; nonpolar or polar olefin homopolymers and copolymers produced by grafting or copolymerization with acid anhydrides, (meth)acrylic acid, and / or esters thereof; carboxylic acid-functionalized copolymers, such as poly(ethylene-co-(meth)acrylic acid) or poly(ethylene-co-1-olefin-co-(meth)acrylic acid) (wherein 1-olefin may be an alkene or unsaturated (meth)acrylic acid ester having more than four atoms), wherein the acid group is partially neutralized by a metal ion, or mixtures thereof.
[0029] Examples of styrene-based block copolymers include styrene-(ethylene-butylene) diblock and styrene-(ethylene-butylene)-styrene triblock copolymer. In a further preferred embodiment, the molding composition according to the present invention is characterized in that component (C) is a polyolefin homopolymer or an ethylene-α-olefin copolymer, particularly preferably EP and / or EPDM elastomer (ethylene-propylene rubber or ethylene-propylene-diene rubber). For example, this may be an elastomer based on an ethylene-C3-12-α-olefin copolymer having 20 to 96, preferably 25 to 85% by mass of ethylene, where C3-12-α-olefin is particularly preferably an olefin selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and / or 1-dodecene, and component (C) is particularly preferably ethylene-propylene rubber and / or LLDPE and / or VLDPE.
[0030] Alternatively or further (for example in a mixture), (C) may contain a terpolymer based on ethylene-C3-12-α-olefin and a non-conjugated diene, which preferably contains 25 to 85% by mass of ethylene and up to 10% by mass of a non-conjugated diene, the C3-12-α-olefin being particularly preferably an olefin selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and / or 1-dodecene, and / or the non-conjugated diene being preferably selected from the group consisting of bicyclo(2.2.1)heptadiene, hexadiene-1.4, dicyclopentadiene, and / or, in particular, 5-ethylidenenorbornene. Ethylene acrylate or ethylene-butylene acrylate copolymer is also suitable as a component of component (C).
[0031] Preferably, component (C) has components having a carboxylic acid group or a carboxylic acid anhydride group, which are introduced in sufficient concentration for good bonding with the polyamide by a thermal or radical reaction between the main chain polymer and an unsaturated dicarboxylic acid anhydride, unsaturated dicarboxylic acid, or unsaturated dicarboxylic acid monoalkyl ester, and reagents selected from the following group: maleic acid, maleic anhydride, monobutyl maleate, fumaric acid, aconitic acid, and / or itaconic anhydride are preferably used for this purpose. Preferably, 0.1 to 4.0% by mass of an unsaturated anhydride is grafted onto the impact-resistant component as component (C), or an unsaturated dicarboxylic acid anhydride or its precursor is grafted together with a further unsaturated monomer. Generally, the degree of grafting is preferably in the range of 0.1 to 1.0%, and particularly preferably in the range of 0.3 to 0.7%. A mixture of ethylene-propylene copolymer and ethylene-butylene copolymer having a maleic anhydride grafting degree (MAH grafting degree) in the range of 0.3 to 0.7% can also be considered as a component of component (C). Possible systems of the components shown above can also be used in the mixture.
[0032] Examples of SZM used as component (C) include homopolymers or copolymers of olefins such as ethylene, propylene, and butene-1, or copolymers of olefins and copolymerizable monomers, such as vinyl acetate, (meth)acrylic acid esters, and methylhexadiene. Examples of crystalline olefin polymers include low-density, medium-density, and high-density polyethylene, polypropylene, polybutadiene, poly-4-methylpentene, ethylene-propylene block or 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-propylene-diene copolymer, and combinations of the polymers described.
[0033] Examples of commercially available impact modifiers that can be used as components (C) include: TAFMER MC201: g-MAH (-0.6%) blend of 67% EP copolymer (20 mol% propylene) + 33% EB copolymer (15 mol% butene-1); TAFMER MH5010: g-MAH (-0.6%) ethylene-butylene copolymer; TAFMER MH7010: g-MAH (0.7%) ethylene-butylene copolymer; Mitsui.TAFMER MH7020: g-MAH (0.7%) EP copolymer from Mitsui Chemicals, Inc.; EXXELOR VA1801: g-MAH (0.7%) EP copolymer; EXXELOR VA1803: g-MAH (0.5~0.9%) EP copolymer, amorphous; EXXELOR VA1810: g-MAH (0.5%) EP copolymer; EXXELOR MDEX94-1 1: g-MAH (0.7%) EPDM, Exxon Mobile Chemical; FUSABOND MN493D: g-MAH (0.5%) ethylene-octene copolymer; FUSABOND A EB560D (g-MAH) ethylene-n-butyl acrylate copolymer, ELVALOY, DuPont; Kraton FG1901GT: g-MAH (1.7%) SEBS with an S-to-EB ratio of 30:70; Lotader AX8840: ethylene-glycidyl methacrylate copolymer. Ionomers are also preferred as component (C), in which the carboxyl groups bonded to the polymer are completely or partially bonded to each other by metal ions.
[0034] Particularly preferred are butadiene-styrene copolymers functionalized by grafting with maleic anhydride, nonpolar or polar olefin homopolymers and copolymers produced by grafting with maleic anhydride, and carboxylic acid-functionalized copolymers such as poly(ethene-co-(meth)acrylic acid) or poly(ethene-co-1-olefin-co-(meth)acrylic acid) in which the acid groups are partially neutralized by metal ions. The additives of component (D) are preferably selected from the following group: polymers, particularly polyamides different from components (A), (C), and (E); stabilizers, anti-aging agents, antioxidants, ozone degradation inhibitors, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic thermal stabilizers, particularly those based on copper halides and alkali metal halides; organic thermal stabilizers; conductive additives; carbon black; fluorescent whitening agents; processing aids; nucleating agents; crystallization accelerators; crystallization retarders; flow aids; lubricants; release agents; plasticizers; pigments; dyes; labeling agents; and mixtures thereof. Polymers other than (A), (C), and (E) include polycarbonate, polystyrene, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polyolefin, polyoxymethylene, polyester, especially polyethylene terephthalate, polybutylene terephthalate, polysulfone (especially PSU, PESU, PPSU types), polyphenylene ether, polyphenylene sulfide, polyphenylene oxide, liquid crystal polymer, polyether ketone, polyether ether ketone, polyimide, aliphatic polyamide, polyamide imide, polyesterimide, polyetheramide, polyesteramide, polyether esteramide, polyurethane (especially TPU, PUR types), polysiloxane, polyacrylate, polymethacrylate, and mixtures or copolymers based on these systems.
[0035] The additive of component (D) preferably contains a purely aliphatic polyamide selected from the group consisting of PA6, PA66, PA10, PA11, PA12, PA516, PA610, PA612, PA614, PA616, PA618, PA1010, PA1012, PA1014, PA1016, PA1018, and mixtures thereof, with PA10, PA11, PA12, PA516, PA612, PA616, PA1010, PA1012, PA1016, PA1212, and mixtures thereof being preferred. The amorphous, partially aromatic polyamide of component (E) is preferably selected as an amorphous, partially aromatic copolyamide, and more preferably as a copolyamide 6I / 6T having a 6T content in the range of 20 to 45 mol%.
[0036] Compared to semicrystalline polyamides, amorphous polyamides have no heat of fusion, or only a very low, barely detectable heat of fusion. In differential scanning calorimetry (DSC) according to ISO 11357 (2013), amorphous polyamides exhibit a heat of fusion of preferably less than 5 J / g, particularly preferably a maximum of 3 J / g, and most preferably 0 to 1 J / g, at a heating rate of 20 K / min. Due to their amorphous nature, amorphous polyamides have no melting point. A “flowmeter” test specimen made from a polyamide molding compound preferably has a burst pressure of at least 70 MPa, preferably at least 90 MPa, and particularly preferably at least 100 MPa, as measured according to the procedure described. A standardized test specimen, a "tensile rod with a front weld line," made from a polyamide molding compound, preferably has a breaking stress of at least 90 MPa in the absence of chemical exposure in the presence of the weld line. The fracture stress is understood to be the strength of the weld line, as measured as specified in the description below. A test specimen "tensile bar with front weld line" (weld line tensile bar) made from a polyamide molding compound preferably has a tensile strength of at least 50 MPa, preferably at least 60 MPa, after storage in a mixture of ethylene glycol and water at 130°C for at least 500 hours.
[0037] The test specimen, "tensile bar with front weld line" (weld line tensile bar), preferably has a tensile strength of at least 25 MPa, preferably at least 40 MPa, and particularly preferably at least 50 MPa after storage in a mixture of ethylene glycol and water at 130°C for at least 1000 hours. The present invention also relates to a molded article containing, and preferably composed of, such a polyamide molding compound. The present invention also relates to a method for producing such a molded article, characterized by melting such a polyamide molding compound and forming it in an injection molding process to form a molded article, preferably with at least one weld line. Finally, the present invention relates to a method for producing such a polyamide molding compound, characterized by melting and mixing components (A) and (B), and (C) and / or (D) if applicable, preferably in an extruder, and then optionally subjecting the mixture to a post-melt condensation process at a temperature of 320 to 360°C. Further embodiments are specified in the dependent claims. Preferred embodiments of the present invention are described below with reference to the drawings, which are for illustrative purposes only and should not be construed as limiting. [Brief explanation of the drawing]
[0038] [Figure 1] This is a diagram of a test specimen (flow meter) used to measure burst pressure. a) shows the first perspective view, and b) shows the second perspective view including weld lines A and B. [Modes for carrying out the invention]
[0039] The following embodiments are intended to illustrate the subject matter of the present invention in more detail, without limiting the invention to the specific embodiments shown herein. Starting materials The materials used in the examples and comparative examples are as follows: Ingredient A: Polyamide type A: Partially crystalline, partially aromatic polyamide PA 6T / 6I, made from 1,6-hexanediamine, terephthalic acid (70 mol%), and isophthalic acid (30 mol%), with a melting point of 325°C and a relative viscosity of 1.67; Polyamide type A1: Semicrystalline, semi-aromatic polyamide PA 6T / 6I / 6, made from 1,6-hexanediamine, terephthalic acid (72 mol%), isophthalic acid (18 mol%), and caprolactam (10 mol%), with a melting point of 304°C and a relative viscosity of 1.63. Component E: Polyamide type B: Amorphous, semi-aromatic polyamide PA 6I / 6T, made from 1,6-hexanediamine, terephthalic acid (33 mol%), and isophthalic acid (67 mol%), with a glass transition temperature of 125°C and a relative viscosity of 1.57; Component B: Glass fiber type 1A: Nittobo CS3DE-256, average diameter 6 μm, length 3 mm. The glass fiber coating contains aminopropyltriethoxysilane and polyurethane resin, but does not contain the components of type b2 (not conforming to the present invention); Glass fiber type 1Ba:CPIC 301HP-DE, average diameter 6 μm, length 3 mm, the glass fiber coating contains aminopropyltriethoxysilane (b1), polyacrylic acid (b2), and polyurethane resin (b3). Glass fiber type 1Bb: NEG 289-DE, average diameter 6 μm, length 3 mm, the glass fiber coating contains aminopropyltriethoxysilane (b1), polyacrylic acid (b2), and polyurethane resin (b3). Glass fiber type 1Bc: Nittobo CSG3-810DE, average diameter 6 μm, length 3 mm, the glass fiber coating contains aminopropyltriethoxysilane (b1), polyacrylic acid (b2), and polyurethane resin (b3). Glass fiber type 2A: Vetrotex 995 EC10-4.5, average diameter 10 μm, length 4.5 mm, glass fiber coating containing aminopropyltriethoxysilane and polyurethane resin (not conforming to the present invention); Glass fiber type 2B: CPIC 301HP, average diameter 10 μm, length 3 mm, glass fiber finishing agent containing aminopropyltriethoxysilane (b1), polyacrylic acid (b2), and polyurethane resin (b3) (not conforming to the present invention); Component C: SZM-1: Impact modifier, a blend of ethylene / propylene copolymer and ethylene / 1-butene copolymer in a mass ratio of 67:33, 0.6% by mass of maleic anhydride, Tafmer MC201 (Mitsui Chemicals, Inc., Japan), SZM-2: Impact modifier, ethylene glycidyl methacrylate copolymer (92% ethene and 8% glycidyl methacrylate copolymer), Lotader AX8840 (Arkema, France) SZM-3: Impact modifier, partially neutralized with zinc ions, ethylene-methacrylate terpolymer, Surlyn 9320 (DuPont). Component D: Stabilizer: A mixture of Hostanox PAR24 (based on tris-(2,4-di-tert-butylphenyl) phosphine) and Irganox 1098 (N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide]) in a 1:1 mass ratio. Color Masterbatch: MB PA66 / Black Pearls 4750 (75 / 25% mass) [Examples]
[0040] Examples and Comparative Examples Manufacturing of PA molding compound To produce the polyamide molding compound according to the present invention, components (A) and (B), and (C) and (D) if necessary, are mixed in a conventional compounding machine such as a single-screw or twin-screw extruder or screw kneader. The components are supplied individually or in the form of a dry blend to a supply hopper by a gravimetric weighing and feeding scale, or separately to a supply hopper and a side feeder. Component (B) is preferably introduced into the polymer molten material by a side feeder.
[0041] When additives (components C and D) are used, they can be added directly or in the form of a masterbatch. The carrier material of the masterbatch is preferably a polyamide or polyolefin. Among polyamides, polyamides of component (A), PA66, PA610, PA11, PA12, PA612, PA1010, or PA1212 are particularly suitable for this purpose.
[0042] The components listed in Table 2 were compounded using a twin-screw extruder from Werner und Pfleiderer with a 25 mm screw diameter, according to the specified process parameters (Table 1A). This introduced polyamide granules and additives into the feed zone, while simultaneously introducing glass fibers into the polymer molten material via three housing units of a side feeder in front of the nozzle. The compound was extruded as strands through a nozzle with a diameter of 2.5 mm, water-cooled, and then granulated. The granules were dried at 110°C in a vacuum of 30 mbar for 24 hours.
[0043] [Table 1]
[0044] [Table 2]
[0045] [Table 3]
[0046] Manufacturing of test specimens Test specimens (tensile rods, and tensile rods with a front weld line, also called weld line tensile rods) were manufactured using an Arburg Allrounder 320-210-750 injection molding machine with specified process parameters (Table 1C), cylinder temperatures set between 330°C and 365°C, and a screw peripheral speed of 16 m / min. The molding temperature was set to 170°C. Using an ENGEL e-victory 120 injection molding machine equipped with a hot runner, a "flow meter" test specimen was manufactured with a cylinder temperature set between 320°C and 340°C and a screw speed of 120 rpm. The process parameters for injection molding the "flow meter" are summarized in Table 1B. The illustrated test specimen "flowmeter" for measuring burst pressure has a length of 130 mm, an inner diameter of 21 mm for the main pipe 2, an inner diameter of 11 mm for the connecting piece 3, a wall thickness of 3 mm in the main pipe region, and a wall thickness of 1.7 mm in the connecting region, with weld lines A and B (arrows in b) schematically shown in Figure 1. G1” threads are formed at each end of the main pipe 2, and a G3 / 8” thread is formed on the connecting piece 3. Weld line A is usually the first weld line to break, and the first weld line to break must be taken into consideration in the value of the weld line strength (measured as burst pressure).
[0047] Measurement method Tensile modulus: ISO 527 at a tensile speed of 1 mm / min, ISO tensile bar (manufactured using opposing injection points at the ends of the test piece so that the flowing molding compound flows from the outside to the center of the mold cavity and the weld line is formed in the center of the molded body), standard: ISO / CD 3167, type A1, 170 × 20 / 10 × 4 mm, temperature 23℃. Tensile strength, elongation at break, and fracture energy: ISO 527 at a tensile speed of 5 mm / min. ISO tensile bar. Standard: ISO / CD3167, Type A1, 170×20 / 10×4 mm, temperature 23℃. ISO tensile bars were manufactured using opposing injection points at the ends of the test specimen, such that the flowing molding compound flowed from the outside towards the center of the mold cavity, forming a weld line in the center of the molded body.
[0048] Relative viscosity: DIN EN ISO 307, in m-cresol solution, 0.5% by mass, at 20°C. Melting point (T m ) and enthalpy of melting (ΔH m The melting point of the granular material was measured in accordance with ISO 11357-3 (2018). Differential scanning calorimetry (DSC) was performed at a heating rate of 20 K / min. After the first heating, the sample was rapidly cooled in dry ice. The melting point was measured during the second heating. The temperature at the peak maximum value was defined as the melting point. Burst pressure: Flow meters with closed free connections were filled with water, mounted on a burst pressure test rig using hydraulic quick couplings, and subjected to burst pressure tests (short-term internal pressure load until rupture) with a pressure increase of 2 bar / s at 23°C. The table shows the maximum pressure reached (average value of 5 samples). Hydrolysis stability of the coolant: Hydrolysis stability is measured in accordance with GM standard GMW15468 (2011). For this purpose, dry test specimens (ISO tensile bars) as manufactured by injection molding are stored in a glycol-water mixture (1:1) in a pressure vessel at 130°C for 504 hours. The glycol used is VW coolant additive G13 in accordance with standard VW TL 774 J. After storage, the test specimens are cooled to 23°C in the coolant, rinsed with water after removal from the coolant, wiped dry with a cotton cloth, and stored in a desiccator on silica gel. Within 7 days of sampling, the above tensile test in accordance with ISO 527 is performed on the stored test specimens.
[0049] result Tables 2 and 3 record the measurements taken, along with the compositions of the polyamide molding compounds according to the present invention and the comparative examples. [Table 4] When using a 6-micrometer thin glass fiber having the sizing according to the present invention, it can be seen that the burst pressure becomes significantly higher immediately after injection molding, that is, significantly exceeding 70, exceeding 80, or even exceeding 90 or 100 bar. Regarding the weldline tensile rod, the strength of the weldline, as recorded as fracture stress, is slightly higher in the initial state (before storage) for the 6-micrometer thin glass fiber according to the present invention than for the glass fiber with a cross-section of 10 micrometers.
[0050] [Table 5] The special and unexpected advantages of the molding compound according to the present invention, having glass fibers according to the present invention with polyacrylic acid-containing sizing, become apparent when the component is exposed to chemicals at high temperatures for extended periods, in this case particularly when exposed to an equal amount of ethylene glycol and water mixture at 130°C. In Comparative Examples 1 and 2, the weld line strength was halved after only 500 hours, while Examples B1 and B3 show a very small decrease in weld line strength. The additional use of component (E) in Examples B6 and B7 results in a further improvement in fracture stress (weld line strength of the tensile rod) both before and after storage in the glycol-water mixture at 130°C. A comparison with VB5 clearly shows that this improvement can only be achieved by using glass fibers according to the present invention; type 2A glass fibers result in significantly lower tensile strength before and after storage in glycol / water. When using the polyamide molding compound according to the present invention, having glass fibers according to the present invention with polyacrylic acid-containing sizing, the elongation at break also becomes significantly more stable, and the same applies to the fracture energy when using the polyamide molding compound according to the present invention.
[0051] Table 4 below records further examples BB1 to BB6 according to the present invention and a further comparative example VBB1 using other types of impact-resistant modifiers. [Table 6]
[0052] Table 5 below records further examples BB8-BB9 according to the present invention, and a further comparative example VBB2 using a further type of polyamide of component A. [Table 7]
[0053] The special and unexpected advantages of the molding compound of the present invention, which has glass fibers having polyacrylic acid-containing sizing, are particularly evident when the component is exposed to chemicals at high temperatures for extended periods, in this case especially when exposed to a mixture of equal parts ethylene glycol and water at 130°C. When using the polyamide molding compound according to the present invention, which has glass fibers containing polyacrylic acid sizing, the elongation at break is also significantly increased, and the same applies to the fracture energy when using the polyamide molding compound according to the present invention. Table 4 shows that storage in water at 95°C results in almost no decrease in weld line strength (fracture stress, since fracture occurs at the weld line) in Examples BB1 to BB6 according to the present invention. Furthermore, Examples BB1 to BB6 demonstrate that good weld line strength can be achieved by using various impact resistance modifiers. When stored in water at 125°C according to Table 5, the weld lines of Examples BB7 and BB8 maintain a high level compared to the initial value and decrease only slightly. Comparative Example VBB2 already starts with a significantly low level of weld line strength, and storage in water at 125°C causes this value to decrease significantly compared to BB7 and BB8. [Explanation of symbols]
[0054] 1. Test specimen for measuring burst pressure: "flow meter" 2 Main manager 3 sockets 4 Spruce A, B Weldline GF glass fiber SZM Impact Resistance Enhancer
Claims
1. A thermoplastic polyamide molding compound comprising the following components: (A) 30 to 74.5% by mass of at least one semicrystalline, semi-aromatic copolyamide 6T / Z having a melting point of at least 270°C, The polyamide unit Z is composed of at least one lactam or one aminocarboxylic acid, and / or is composed of a polyamide unit different from 6T, consisting of at least one diamine and at least one dicarboxylic acid. In 6T / Z, the content of 6T exceeds 50 mol% based on the molar percentage of all polyamide units. Semicrystalline, semi-aromatic copolyamide 6T / Z, (B) Glass fibers having an average diameter of 5 to 8 μm, comprising 25 to 50% by mass, (b1) at least one silane compound, (b2) at least one polymer or copolymer based on an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride, (b3) At least one epoxy, polyurethane, or polyamide resin The glass fiber is coated with a sizing composition (b) containing, but if component (b1) or component (b3) is a system containing a carboxylic acid and / or a carboxylic acid anhydride, the sizing composition does not need to contain component (b2). (C) 0.5 to 8% by mass of impact resistance modifier, (E) 0 to 20% by mass of amorphous partially aromatic polyamide, (D) Additives other than (A) to (C) and (E) in amounts of 0 to 10% by mass and It consists of, The sum of the amounts of components (A) to (E) equals 100% by mass of the polyamide molding compound. Thermoplastic polyamide molding compound.
2. The Z of component (A) is It is composed of polyamide units derived from at least one lactam or aminocarboxylic acid having at least four, preferably five to twelve, carbon atoms, wherein the lactam and / or aminocarboxylic acid are preferably selected as aliphatic linear systems. Furthermore / or, Z is composed of a polyamide unit different from 6T, comprising at least one diamine having 5 to 12 carbon atoms and at least one dicarboxylic acid having 5 to 12 carbon atoms, wherein the diamine is preferably selected as an aliphatic linear or cyclic diamine, and more preferably the dicarboxylic acid is selected as an aliphatic linear dicarboxylic acid. The polyamide molding composition according to claim 1, characterized in that
3. The polyamide molding composition according to claim 1 or 2, characterized in that the copolyamide of structure 6T / Z is selected from the group consisting of 6T / 6I, 6T / DT, 6T / BACT, 6T / 66, 6T / 610, 6T / 612, 6T / 6I / 6, 6T / 6I / 66, 6T / 6I / 610, 6T / 6I / 612, or mixtures thereof, preferably with a content of polyamide units other than 6T, particularly 6I, DT, 66, 610, 612, or BACT exceeding 20%, and the copolyamide may further contain polyamide units XY selected from the group consisting of 56, 66, 610, 612, BACI, BAC6, BAC10, and BAC12 in a proportion of less than 30 mol%.
4. The polyamide molding composition according to any one of claims 1 to 3, characterized in that the copolyamide 6T / Z is selected as 6T / 6I in a proportion of 6T polyamide units in the range of 60 to 80 mol%, preferably 65 to 75 mol%.
5. The proportion of component (A) is in the range of 37 to 74.5% by mass or 42 to 70% by mass, preferably in the range of 48 to 64.4% by mass. and / or the proportion of component (B) is in the range of 30 to 45% by mass, preferably in the range of 35 to 42% by mass. and / or the proportion of component (C) is in the range of 0.5 to 6% by mass or 0.5 to 5% by mass, preferably in the range of 0.7 to 5.0% by mass or 0.7 to 3.5% by mass. and / or the proportion of component (E) is in the range of 5 to 20% by mass, preferably in the range of 6 to 16% by mass. and / or the proportion of component (D) is in the range of 0 to 7% by mass, preferably in the range of 0.1 to 5.0% by mass. The sum of components (A) to (E) equals 100% by mass of the polyamide molding compound. A polyamide molding composition according to any one of claims 1 to 4.
6. Sizing composition (b) The component (b1) contains a silane, preferably an aminoalkyltrialkoxysilane, more preferably an aminoalkyltriethoxysilane, and particularly preferably at least one aminopropyltriethoxysilane or aminopropyltriethoxysilane. and / or component (b2) contains at least one polyacrylic acid or olefin-maleic anhydride copolymer, and / or containing polyurethane resin as component (b3), The sizing composition preferably contains three components (b1) to (b3) as a mixture or multilayer coating, preferably as a mixture of aminopropyltriethoxysilane, polyacrylic acid or olefin-maleic anhydride copolymer and polyurethane resin. A polyamide molding composition according to any one of claims 1 to 5, characterized in that
7. The impact-modifying agent of component (C) is from the following group: natural rubber, polybutadiene, polyisoprene, polyisobutylene; copolymers of butadiene and / or isoprene with styrene or styrene derivatives; hydrogenated copolymers of this type; copolymers formed by grafting or copolymerization with acid anhydrides, (meth)acrylic acid, and their esters; graft rubber having a crosslinked elastomer core made of butadiene, isoprene, and / or alkyl acrylate, and a polystyrene graft shell; olefin homopolymers including ethylene-propylene, ethylene-butylene, ethylene-propylene-diene, and ethylene-octene or ethylene-vinyl acetate rubber. The polyamide molding composition according to any one of claims 1 to 6, characterized by comprising: and copolymers; non-polar or polar olefin homopolymers and copolymers produced by grafting or copolymerization with acid anhydrides, (meth)acrylic acid, and / or esters thereof; carboxylic acid-functionalized copolymers, such as poly(ethylene-co-(meth)acrylic acid) or poly(ethylene-co-1-olefin-co-(meth)acrylic acid) (wherein 1-olefin may be an alkene having more than four atoms or an unsaturated (meth)acrylic acid ester), wherein the acid groups are partially neutralized by metal ions, such copolymers, or mixtures thereof.
8. The additives of component (D) are selected from the following groups: polymers, particularly polyamides different from components (A), (C), and (E); stabilizers, anti-aging agents, antioxidants, ozone degradation inhibitors, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic thermal stabilizers, particularly those based on copper halides and alkali metal halides; organic thermal stabilizers; conductive additives; carbon black; fluorescent whitening agents; processing aids; nucleating agents; crystallization accelerators; crystallization retarders; flow aids; lubricants; release agents; plasticizers; pigments; dyes; labeling agents; and mixtures thereof. Furthermore / or component (E) is selected as an amorphous, partially aromatic polyamide, particularly as copolyamide 6I / 6T, preferably as copolyamide 6I / 6T having a 6T content in the range of 20 to 45 mol%. A polyamide molding composition according to any one of claims 1 to 7, characterized in that
9. A polyamide molding compound according to any one of claims 1 to 8, characterized in that the additive of component (D) contains a polyamide different from components (A) and (E), particularly preferably a purely aliphatic polyamide selected from the group consisting of PA 10, PA 11, PA 12, PA 516, PA 6, PA 66, PA 610, PA 612, PA 614, PA 616, PA 618, PA 1010, PA 1012, PA 1014, PA 1016, PA 1018, and mixtures thereof, wherein PA 10, PA 11, PA 12, PA 516, PA 612, PA 616, PA 1010, PA 1012, PA 1016, PA 1212, and mixtures thereof are preferred.
10. A flow meter test specimen manufactured from a polyamide molding compound has a burst pressure of at least 70 MPa, preferably at least 90 MPa, and particularly preferably at least 100 MPa, as described. Furthermore / or, a standard object made from a polyamide molding compound that has not been chemically exposed has a fracture stress of at least 90 MPa in the presence of weld lines. Furthermore / or, after storage in a mixture of ethylene glycol and water (1:1) at 130°C for at least 500 hours, having a fracture stress of at least 50 MPa, preferably at least 60 MPa. A polyamide molding compound according to any one of claims 1 to 9, characterized by the above.
11. A molded article containing, preferably comprising, the polyamide molding compound described in any one of claims 1 to 10.
12. A method for producing a molded article according to claim 11, characterized by melting a polyamide molding compound according to any one of claims 1 to 10, molding it in an injection molding process to form a molded article, thereby forming at least one weld line.
13. A method for producing a polyamide molding compound according to any one of claims 1 to 10, characterized by melting and mixing components (A) and (B), and (C) and / or (D) and / or (E) if applicable, preferably in an extruder, and then subjecting the mixture to a post-melt condensation process at a temperature of 320 to 360°C.