CN112533993A - Fiber-reinforced polyamide composition and molded article made therefrom - Google Patents
Fiber-reinforced polyamide composition and molded article made therefrom Download PDFInfo
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- CN112533993A CN112533993A CN201980051050.3A CN201980051050A CN112533993A CN 112533993 A CN112533993 A CN 112533993A CN 201980051050 A CN201980051050 A CN 201980051050A CN 112533993 A CN112533993 A CN 112533993A
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
- C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
Abstract
The invention relates to fiber-reinforced polyamide compositions and molded parts made therefrom. The fiber reinforced polyamide composition comprises (A)30 to 70 wt.% of a thermoplastic polyamide, (B)10 to 60 wt.% of a fiber reinforcement, and (C)0.5 to 10 wt.% of a silicone block-containing polymer.
Description
The present invention relates to a fiber reinforced polyamide composition comprising a thermoplastic polyamide, a fiber reinforcement and a polymer comprising silicone blocks. In a preferred embodiment, the composition according to the invention comprises a flame retardant. The invention also relates to a moulded part made of this composition.
A fiber reinforced polyamide composition comprising a thermoplastic polyamide and a reinforcing agent; and a polyamide composition comprising a thermoplastic polyamide, a reinforcing agent and a flame retardant; and molded parts made from them are well known in the art to impart flame retardancy to molded parts using good properties, such as chemical and temperature resistance of thermoplastic polyamides and mechanical strength and load bearing properties of fiber reinforcements, as well as flame retardants, as required in many applications.
Such reinforced polyamide compositions and reinforced flame retardant polyamide compositions can also cause warpage problems. Warpage (warping) is a phenomenon in which molded articles are deformed. Warpage may occur directly after molding, or after aging, or after annealing or after a heat treatment step (e.g., during a reflow soldering process). The molded article is liable to warp, particularly when the molded article has a long extended shape in one direction or a wide extended shape in two directions, or a complicated three-dimensional shape having a thin portion. Reinforced polyamide compositions and warpage problems are described in several patent applications including the following.
JP2001226579A relates to a reinforced polyamide resin composition suitable for use in industrial products such as automobile parts, electronic and electric parts, and industrial machine parts. The molded product should have low warpage and excellent rigidity, strength and heat resistance, and have freeze resistance durability and vibration fatigue resistance. The solution proposed in JP2001226579A is a reinforced polyamide resin composition comprising (a) a polyamide, (B) an apatite compound, and (C) an inorganic filler. The apatite compound must contain an organic substance insoluble in a phenolic solvent.
US2010076137A relates to a flame retardant polyamide composition and molded articles produced from the composition. The molded article should have excellent mechanical properties including rigidity, heat resistance and flame retardancy, and exhibit low warpage during a reflow soldering process. The solution proposed in US2010076137A is a flame retardant polyamide composition comprising 20 to 80% by weight of a specific polyamide resin (a), 1 to 40% by weight of a flame retardant (B), 5 to 60% by weight of glass fibers (C) and 0.5 to 5% by weight of an auxiliary flame retardant (D). Preferably, the aspect ratio of the cross section of the glass fiber (C) is greater than 3.
JP10130494A relates to a polyamide resin composition having high rigidity, low warpage, good surface smoothness and excellent appearance. The solution proposed in JP10130494A is a polyamide composition comprising 35 to 65% by weight of a mixed polyamide resin consisting of 50 to 95% by weight of a crystalline polyamide resin and 50 to 5% by weight of an amorphous polyamide resin; 10 to 60 weight percent of a fiber reinforcement; and 5 to 55 wt% of an flat silicate. Preferred flat silicates include mica and talc.
JP2255764A also solves the problem of reducing warpage of molded articles produced by mixing (a) crystalline polyamide (e.g., nylon 6 or nylon 46) with (B) a fibrous reinforcing material while maintaining heat resistance, rigidity and impact strength of the molded articles. JP2255764A proposes a method for preventing warpage of a crystalline polyamide molded article by adding a specific amount (3 to 40 wt%) of a specific amorphous copolyamide (C) to a resin composition. The amorphous copolyamide (C) is derived from 50 to 10 mol% of isophthalic acid, 0 to 40 mol% of terephthalic acid, 45 to 5 mol% of hexamethylenediamine and 5 to 45 mol% of bis (4-amino-3-methylcyclohexyl) methane [ mol% based on the total acid content and the total diamine content ] and preferably has a glass transition temperature of 100 ℃ or more and a relative viscosity of 1.2 to 3.
JP2014152322A aims to provide a polyamide resin composition having high flame retardancy (UL standard 94: V-0, thickness of 0.8mm), as well as excellent mechanical properties, toughness and low warpage. The solution proposed in JP2014152322A is a flame retardant polyamide resin composition with a specific combination of flame retardants, which composition comprises 10 to 70 mass% of a polyamide resin (a), 1 to 40 mass% of an organic phosphinate salt (B), 0.1 to 15.0 mass% of a melamine polyphosphate-based compound (C), 0.1 to 30 mass% of a phosphazene-based compound (D), and 10 to 60 mass% of a fiber reinforcement (E).
US2010227122A describes portable electronic devices and suitable polyamide resin compositions mixed with glass fibres. It is mentioned in US2010227122A that in recent years these devices have become thinner and lighter in weight, and therefore polyamide resin compositions suitable for use as materials for use therein are required to have particularly excellent strength and low warpage properties. The polyamide resin composition according to the solution provided by US2010227122A comprises (a)60 to 34 wt.% of a polyamide resin, (B) glass fibers having an elongated cross section with an aspect ratio of 2.5 or more, and optionally (C) glass fibers having a circular cross section with a diameter of 3 to 30 (micrometers), wherein the weight ratio of component (B) to component (C) is 3:7 to 10:0, and the amount of (B) or (B) and (C) is 40 to 66 wt.%, and wherein the polyamide composition exhibits a tensile strength of 200MPa or more.
WO08120703a1 provides a solution for a glass fiber reinforced polyamide resin composition having simultaneously good mechanical properties, low warpage and satisfactory weld strength suitable for forming thin molded parts, such as chassis (chassis) or housings (housing) of electronic devices. The composition comprises 30 to 80 mass% of a polyamide resin having a relative viscosity of 1.5 to 4.0, 20 to 70 mass% of a flat glass fiber having a flat section with a long diameter/short diameter ratio of 1.5 to 10, and an organic compound having at least two glycidyl groups or acid anhydride groups per molecule, the organic compound being mixed in an amount of 0.05 to 4.0 parts by mass with respect to 100 parts by mass of the polyamide resin.
In view of the above, there is clearly a need for fiber reinforced polyamide compositions suitable for producing molded articles having low warpage.
It is therefore an object of the present invention to provide a fiber-reinforced polyamide composition and molded articles made therefrom having low warpage.
This object has been achieved with the reinforced polyamide composition according to the invention as well as with molded parts.
The reinforced polyamide composition according to the invention comprises (a) a thermoplastic polyamide, (B) a fibrous reinforcing agent and (C) a silicone block containing polymer.
In a first preferred embodiment of the present invention, the composition comprises (D) a flame retardant as another component.
In a second preferred embodiment of the invention, the fibrous reinforcing agent comprises non-round glass fibers.
In a third preferred embodiment, the composition comprises (a) a thermoplastic polyamide, (B) a fibrous reinforcing agent comprising non-round glass fibers, (C) a silicone block containing polymer, and (D) a flame retardant.
In a fourth preferred embodiment, the reinforced polyamide composition according to the invention comprises less than 50% by weight of thermoplastic polyamide (a) and 0.5 to 10% by weight of polymer (C) containing silicone blocks, relative to the total weight of the composition. Such oligoamide content may be combined with high levels of fiber reinforcement and filler.
In another embodiment of the invention, the molded part is made of the composition according to the invention or any of its preferred embodiments described above.
The effect of the composition according to the invention comprising the polymer (C) comprising a silicone block is that a molded part made therefrom shows less warpage than a molded part made from a similar composition not comprising a polymer comprising a silicone block. This effect is most pronounced in moldings comprising extended sections with a large length/width ratio, and in moldings which have been subjected to an overheating treatment (for example in a reflow soldering process).
Silicones, also known as polysiloxanes and more precisely as polymeric siloxanes, consist of an inorganic silicon-oxygen backbone, which is a chain of alternating silicon and oxygen atoms (… -Si-O- …), composed of inorganic-organic monomers with organic side groups attached to the silicon atoms. These silicon atoms are tetravalent. Thus, silicones are polymers composed of siloxane repeating units in combination with carbon, hydrogen, and sometimes other elements. The silicones are generally of the formula- [ R ]2SiO]n-. In the formula, n is a degree of polymerization, and each R may be independently an alkyl group, a haloalkyl group, an aralkyl group, an alkenyl group, an aryl group, or an aryl group substituted with an alkyl group, an alkoxy group, or a halogen atom.
In this context, a polymer comprising a silicone block is understood to be a polymer comprising at least a silicon block, i.e. a polydiorganosiloxane block having an inorganic silicon-oxygen backbone. Herein, the silicone block-containing polymer may comprise one silicon block that is endcapped with a mono-radical group or a monovalent group as represented by formula (I), or more than one silicon block that is interphased with a di-radical group or a divalent group and endcapped with a mono-radical group as represented by formula (II):
X[R2SiO]nY (I)
X([R2SiO]nZ)x[R2SiO]nY (II)
here X and Y represent a mono radical group serving as a terminal group, and Z represents a di radical group serving as an alternating group. Here X and Y may be different or may be the same. Here Z can be a polymer block of a different chemical composition than the polydiorganosiloxane block or the remainder of the chain extender. Typically, the chain extender is a low molecular weight difunctional compound with functional groups capable of reacting with the functional end groups of the polymer. The silicone block containing polymer may also contain a component with higher functionality that acts as a branching agent in place of or in addition to the two functional components that act as chain extenders. Such branching agents are suitably used in small amounts to prevent cross-linking.
Polymers containing silicone blocks suitable for use in the compositions can vary widely in chemistry and structure and include linear polymers containing silicone blocks as well as polydiorganosiloxane block copolymers. The silicone block containing polymer may have a molecular weight that varies over a wide range. Suitably, the weight average molecular weight (Mw) of the polymer comprising the silicone block is greater than 5,000g/mol, or greater than 10,000g/mol, and even greater than 25,000 g/mol. The Mw of the silicone block containing polymer can be as high as 100,000g/mol, and even greater. The polymers containing silicone blocks may also comprise polysiloxane blocks whose degree of polymerization (n) varies within a wide range. Suitably, (n) is at least 3, preferably at least 5, or even more preferably at least 10. (n) suitably has a value of about 25 or about 50 or about 100 or about 200. (n) may be up to about 300 or even higher. Preferably, (n) is in the range of 5-300. Accordingly, the polysiloxane block suitably has a weight average molecular weight (Mw) of at least about 500, preferably at least about 1000, for example about 2000, about 5,000 or about 10,000 or about 20,000, and suitably up to 60,000, or even higher.
The polymers containing silicone blocks used in the fiber-reinforced polyamide compositions according to the invention comprise at least one polysiloxane represented by the formula [ R2SiO]nIs represented by]A silicon block of composition; the silicone block-containing polymer may also comprise other polymeric structural units or polymeric units. Thus, the amount of polysiloxane in the silicone block-containing polymer can vary. Suitably, at least 20 wt%, preferably at least 40 wt%, more preferably at least 60 wt% of the silicone block containing polymer is comprised of polysiloxane. The amount of polysiloxane in the silicone block containing polymer may be, for example, 30 wt%, or 50 wt%, or may be up to 75 wt% or 90 wt% or even higher.
The silicone block containing polymer used in the composition according to the invention is melt processable. The glass transition temperature (Tg) of the silicone block containing polymer is typically well below 0 ℃ and may suitably be as low as about-125 ℃. However, the physical state may differ as different polymer blocks may be added, either the silicon block is part of a segmented block copolymer or is end-functionalized. Depending on the molecular weight of the polymer and the glass transition temperature (Tg) or melting temperature (Tm) of the other blocks, the physical state can vary from a liquid to a thick liquid, waxy solid, or even a solid material. Preferably, the silicone block containing polymer used to prepare the composition according to the invention is a waxy solid material or a solid material at room temperature.
In the composition according to the invention and in the moulded parts made therefrom, the silicone block-containing polymer is suitably a linear silicone block-containing polymer comprising a single radical end group bearing a functional group capable of reacting with a polyamide. This has the advantage of better compatibility with the polyamide. Suitably, the copolymer comprises end groups functionalized with groups selected from amine groups [ the polymer suitably comprises an alkylamino group ], hydroxyl groups [ the polymer suitably comprises an alkyl alcohol ], epoxy groups and carboxylic acid groups.
In the compositions according to the invention and in the moulded parts made therefrom, the polymers containing silicone blocks are suitably polydiorganosiloxane polyamide block copolymers, polydiorganosiloxane polyurethane block copolymers, polydiorganosiloxane polyether block copolymers, polydiorganosiloxane polyester block copolymers or polydiorganosiloxane polycarbonate block copolymers. The polydiorganosiloxane block copolymers here are suitably triblock copolymers comprising a polydiorganosiloxane block terminated with a polyamide block, or a polyurethane block, or a polyether block, or a polyester block, or a polycarbonate block, respectively. Preferably, the silicone block containing polymer comprises at least a polydiorganosiloxane polyester block copolymer. Finally, the silicone block containing polymer comprises at least a polydiorganosiloxane polyester triblock copolymer. More specifically, the polydiorganosiloxane polyester triblock copolymer can comprise polyester blocks containing OH functional end groups.
In the silicone block containing polymer in the composition according to the invention, the silicon-oxygen backbone may comprise different substituents R, wherein R is an organic group; for example, an alkyl group (e.g., methyl, ethyl), or a phenyl or substituted phenyl, or an aralkyl group, or combinations thereof.
In the silicone block containing polymer in the composition according to the invention, the silicon carbon backbone bears a substituent R, wherein R is an organic group, such as an alkyl group (e.g., methyl, ethyl), or a phenyl or substituted phenyl, or an aralkyl group, or a combination thereof. Preferably, R comprises at least a methyl group.
Suitably, the silicone block containing polymer comprises at least a polydimethylsiloxane block, i.e.of the formula- [ (Me)2SiO]n-a block of (a); or a polydiethylsiloxane block; or a polydiphenylsiloxane block; or any combination thereof, or any copolymer thereof, and preferably comprises at least a polydimethylsiloxane block.
The polymer containing a silicone block is preferably present in the composition according to the invention in an amount ranging from 0.5 to 10% by weight, preferably from 1 to 8% by weight and more preferably from 2 to 4% by weight, relative to the total weight of the composition.
The thermoplastic polyamide in the composition according to the invention may be any thermoplastic polyamide that can be used for the manufacture of moulded articles. Suitably, the thermoplastic polyamide comprises a semi-crystalline semi-aromatic polyamide, an amorphous semi-aromatic polyamide or an aliphatic polyamide, or any combination thereof.
Suitably, the aliphatic polyamide is a polylactam [ represented by the designation polyamide X or PA-X, where X is an integer representing the polymerized lactam and the number of carbons therein ]; or a polyamide of the AABB type based on an aliphatic diamine and an aliphatic dicarboxylic acid [ represented by the name polyamide XY or PA-XY, where X and Y are integers, and X represents a diamine, and Y represents an aliphatic dicarboxylic acid ].
Examples of aliphatic polyamides are PA-6, PA-11, PA-12, PA-66, PA-6/66, PA-46 and PA-410, and any copolymers thereof.
Examples of amorphous semi-aromatic polyamides are PA-6I/6T, PA-MXDI, PA-MACT and PA-DT, and any copolymers thereof. Here 6 represents hexamethylenediamine, I represents isophthalic acid, T represents terephthalic acid, MXD represents isophthalic diamine, MAC represents 3,3 '-dimethyl-4, 4' -diaminocyclohexylmethane, and D represents 2-methyl-pentamethylenediamine.
Suitably, the semi-crystalline semi-aromatic polyamide is an AABB type polyamide based on aliphatic diamines and aromatic dicarboxylic acids [ represented by the name polyamide XZ or PA-XZ ] or an AABB type polyamide based on aliphatic diamines, aliphatic dicarboxylic acids and aromatic dicarboxylic acids [ represented by the name polyamide XY/XZ or PA-XY/XZ or polyamide XZ/XY or PA-XZ/XY ]. Here X is an integer and represents a diamine, Y represents an aliphatic dicarboxylic acid, and Z represents an aromatic dicarboxylic acid.
Suitably, the semi-crystalline semi-aromatic polyamide is based on an aromatic dicarboxylic acid selected from terephthalic acid, naphthalenedicarboxylic acid and biphenyldicarboxylic acid, or combinations thereof, optionally in combination with isophthalic acid or aliphatic dicarboxylic acid. The semi-crystalline semi-aromatic polyamide is suitably based on a diamine selected from the group consisting of linear aliphatic diamines, branched aliphatic diamines, cycloaliphatic diamines, aralkyl diamines and aromatic diamines. The linear aliphatic diamine is suitably an alpha omega-alkyldiamine having from 4 to 18 carbon atoms, such as 1, 4-butanediamine, 1, 6-hexamethylenediamine, 1, 7-heptamethylenediamine, 1, 8-diaminooctane, 1, 9-diaminononane, 1, 10-decanediamine and 1, 12-dodecanediamine. Examples of branched aliphatic diamines are 2,2, 4-trimethylhexamethylenediamine, 2,4, 4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine and 2-methyloctanediamine. Examples of cycloaliphatic diamines are isophorone diamine and 1, 4-dimethyl cyclohexane. Examples of the aralkyl diamine are m-xylylenediamine (metaxylylenediamine) and p-xylylenediamine (paraxylylenediamine).
Examples of semi-crystalline semi-aromatic polyamides are PA-6T/6I, PA-6T/66, PA-6T/10T, PA-4T/6T, PA-8T, PA-9T, PA-10T, PA-11T and PA-12T, and any copolymers thereof. Here, 6 at the X position in the XY sequence represents hexamethylenediamine, 6 at the Y position in the XY sequence represents adipic acid, 4 represents 1, 4-butanediamine, 8 represents 1, 8-diaminooctane, 9 represents 1, 9-diaminononane, 10 represents 1, 10-decanediamine, 11 represents 1, 11-undecanediamine, 12 represents 1, 12-dodecanediamine, MXD represents m-xylylenediamine, D represents 2-methylpentamethylenediamine, I represents isophthalic acid, and T represents terephthalic acid.
In a preferred embodiment of the invention, the thermoplastic polyamide comprises a semi-crystalline polyamide having a melting point of at least 260 ℃, more preferably at least 270 ℃, still more preferably at least 280 ℃. The advantage is that the composition is better able to withstand high temperatures, such as those applied in lead-free soldering processes for SMT (surface mount technology) applications, while maintaining low warpage.
Here, the melting temperature (Tm) is determined by the DSC method according to ISO-11357-1/3,2011 at N2Measured on pre-dried samples in an atmosphere at a heating and cooling rate of 20 ℃/min. Herein, Tm is calculated from the peak value of the highest melting peak in the first heating cycle.
The amount of polyamide in the composition according to the invention may vary within wide ranges and may be as low as, for example, about 20% by weight or as high as, for example, about 80% by weight. The polyamide is more suitably present in an amount of from 30 to 70 wt%, preferably from 30 to 60 wt%, more preferably from 40 to 60 wt%. Herein, the weight percentage (wt%) is relative to the total weight of the composition.
The composition according to the invention comprises a fibrous reinforcing agent.
A fiber is herein understood to be an elongated body or elongated particle having an aspect ratio of length (L) to width (W) of at least 10. This is in contrast to fillers, which are understood to be particles having an aspect ratio of length (L) to width (W) of less than 10.
The fibrous reinforcing agent in the thermoplastic polymer composition according to the invention may comprise, for example, fibers selected from the group consisting of: glass fibers, carbon fibers, metal fibers and mineral fibers. Preferably, the composition comprises at least glass fibers or carbon fibers, or a combination thereof. The glass fibers may, for example, be selected from a glass, C glass, D glass, E glass, H glass, M glass, R glass, and S glass, or any mixture thereof. Preference is given to glass fibers made of E-glass or made of a mixture of E-glass fibers and S-glass fibers.
The fibers may be circular, i.e., have a circular cross-section, or may be non-circular, e.g., having a flat, oval, elliptical, oblong, or rectangular cross-section. Among the glass fibers, flat glass fibers are particularly preferable.
The diameter of the Round (Round/circular) glass fibers is suitably from 5 μm to 20 μm, preferably from 5 μm to 15 μm, particularly preferably from 6 μm to 12 μm. The diameter of the carbon fibers is suitably from 3 μm to 15 μm, preferably from 4 μm to 12 μm, particularly preferably from 4 μm to 10 μm.
The non-circular glass fibers suitably have a cross-section with an aspect ratio W/T of width to thickness of at least 1.5, preferably at least 2, more preferably in the range of 2.5-6. Here W denotes the width, i.e. the largest dimension of the cross-section, and T denotes the thickness, i.e. the smallest dimension of the cross-section. Here, the cross-sectional dimensions width (W) and thickness (T) are measured on the cross-section of the fiber perpendicular to the length direction of the cross-section.
An advantage of a composition comprising non-round glass fibres is that the warpage of elongate moulded articles made from the composition is further reduced.
The composition may contain long fibers (LFT fibers), short fibers (staple fibers) or milled fibers, or any combination thereof. The chopped or chopped fibres suitably have a fibre length of from 1mm to 25mm, preferably from 1.5mm to 20mm, more preferably from 2mm to 12mm, most preferably from 2mm to 8 mm.
Preferably, the composition comprises a combination of glass fibers and carbon fibers. Such a combination provides an optimal balance in terms of mechanical properties, cost and weight reduction. Suitably, the fibres consist of 30-70 wt% glass fibres and 70-30 wt% carbon fibres.
Also preferably, the composition comprises at least non-round glass fibers. Suitably, the composition comprises non-round glass fibres and round glass fibres or carbon fibres, or a combination thereof. In a preferred embodiment, the fibers consist of 30 to 70 wt.% flat glass fibers and 70 to 30 wt.% round glass or carbon fibers or a combination thereof.
The amount of fibrous reinforcing agent in the composition according to the invention may vary within wide ranges and may be as low as, for example, about 5% by weight or as high as, for example, about 65% by weight. The fibrous reinforcing agent is more suitably present in an amount of from 10 to 60% by weight, preferably from 20 to 60% by weight, more preferably from 30 to 50% by weight. Herein, the weight percentage (wt%) is relative to the total weight of the composition.
The composition according to the invention suitably comprises:
(A)30-70 wt% of the thermoplastic polyamide;
(B) 10-60% by weight of the fiber reinforcement;
(C)0.5 to 10 weight percent of the silicone block containing polymer;
wherein weight percent (wt%) is relative to the total weight of the composition.
In a preferred embodiment of the present invention, the composition comprises a flame retardant (component (D)) in addition to the polyamide (a), the fiber reinforcement (B) and the silicon block-containing polymer (C). Many applications require molded parts to be flame retardant, have high mechanical strength, and be dimensionally stable after molding, even when subjected to temperature changes (e.g., during reflow soldering). However, in the case where flame retardancy can be achieved by adding a sufficient amount of flame retardant and high mechanical strength can be achieved by adding a sufficient amount of fiber reinforcing agent while reducing the content of the polymer, this generally results in a reduction in warpage. The occurrence of warpage directly after molding and after a heat treatment step, such as during reflow soldering, is further reduced by the presence of the silicon-containing block polymer (C) in the composition according to the invention.
The flame retardant in the composition according to the invention may be a halogen-containing flame retardant or a halogen-free flame retardant, or a combination thereof. Preferably, the flame retardant comprises or even better consists entirely of a halogen-free flame retardant. Suitably, the halogen-free flame retardant is a nitrogen (N) -or phosphorus (P) -containing halogen-free flame retardant, or a nitrogen (N) -and phosphorus (P) -containing halogen-free flame retardant. More preferably, the halogen-free flame retardant comprises or even better consists entirely of a metal phosphinate or a metal diphosphinate or a combination thereof or a polymer thereof, which metal phosphinate or metal diphosphinate or a combination thereof or a polymer thereof are also referred to herein together as a (di) metal phosphinate.
Suitable metal salts of (di) phosphinic acids which can be used in the composition according to the invention are, for example, the phosphinic acid salts of the formula (III), the diphosphinic acid salts of the formula (IV),
or polymers of these, wherein R1 and R2 are the same or different or are linear or branched C1-C6 alkyl and/or aryl groups; r3 is a straight or branched C1-C10 alkylene, C6-C10 arylene, C6-C10 alkylarylene, or C6-C10 arylalkylene; m is one or more of calcium ion, magnesium ion, aluminum ion and zinc ion, and M is 2 to 3; n is 1 or 3; x is 1 or 2. R1 and R2 may be the same or different and are preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl and/or phenyl. R3 is preferably methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, n-pentylene, n-octylene, n-dodecylene, or phenylene or naphthylene, or methylphenylene, ethylphenylene, tert-butylphenylene, methylnaphthylene, ethylnaphthylene or tert-butylnaphthylene, or phenylmethylene, phenylethylene, phenylpropylene or phenylbutylene. M is preferably an aluminum ion or a zinc ion. These compounds are disclosed in U.S. Pat. No. 6,255,371, which is hereby incorporated by reference.
Preferably, the flame retardant (D) comprises an aluminium (di) phosphinate. Suitable examples of such flame retardants are methyl ethyl (di) phosphinate and/or aluminum diethyl (di) phosphinate.
The flame retardant (D) is suitably present in an amount in the range of at least 5 wt% and/or up to 30 wt%, more particularly at least 5 wt% and/or up to 25 wt%. Herein, the weight percentage (wt%) is relative to the total weight of the flame retardant polyamide composition. Preferably, the flame retardant (D) is present in an amount ranging from 5 to 25% by weight, preferably from 7.5 to 20% by weight, relative to the total weight of the composition. If used as flame retardant, the composition suitably comprises the metal (di) phosphinate in an amount in the range of from 5 to 25 wt.%, preferably from 7.5 to 20 wt.%, relative to the total weight of the composition.
In a preferred embodiment of the present invention, the composition comprises:
(D)30-70 wt% of the thermoplastic polyamide;
(E)20-60 wt% of the fiber reinforcement;
(F)0.5 to 10 weight percent of the silicone block containing polymer; and
(G)5-25 wt% of the flame retardant;
wherein the weight percent (wt%) is relative to the total weight of the composition.
In a more preferred embodiment, the composition comprises:
(A)30-60 wt% of the thermoplastic polyamide;
(B) 30-60% by weight of the fiber reinforcement;
(C)1-8 wt% of the silicone block containing polymer; and
(D)7.5 to 20 weight percent of the flame retardant; and is
Wherein the weight percent (wt%) is relative to the total weight of the composition.
The polyamide composition of the invention may optionally comprise further components, such as other polymers and inorganic fillers, and additives selected, for example, from the following: acid scavengers, impact modifiers, plasticizers, stabilizers [ e.g., thermal, oxidative, ultraviolet and chemical stabilizers ], processing aids [ e.g., mold release and nucleating agents ], solid lubricants, colorants [ e.g., carbon black, other pigments, dyes ], nanoclays, and the like. Impact modifiers are advantageously included to further improve the impact resistance of, for example, parts and housings of electronic devices.
Fillers which can be used are all particulate fillers known to the person skilled in the art. These fillers include in particular particulate fillers selected from the group consisting of: minerals, talc, mica, marble, silicates, quartz, wollastonite, kaolin, silicic acid, magnesium carbonate, magnesium hydroxide, chalk, ground glass, glass flakes, metal coated particles, ground carbon fibers, ground mineral fibers, ground glass fibers, ground or precipitated calcium carbonate, lime, feldspar, barium sulfate, permanent or magnetizable metals or alloys, glass beads, hollow spherical silicate fillers, and mixtures thereof.
The composition according to the invention suitably comprises at least one further component (E). The at least one further component (E) is suitably present in an amount ranging from 0.01 to 40% by weight, preferably from 0.05 to 25% by weight, relative to the total weight of the composition.
According to a preferred embodiment, the composition consists of:
(A)30-70 wt% of the thermoplastic polyamide;
(B)20-60 wt% of the fiber reinforcement;
(C)0.5 to 10 weight percent of the silicone block containing polymer;
(D)0-25 wt% of the flame retardant; and
(E)0.01 to 40 wt% of the at least one additional component;
wherein the weight percent (wt%) is relative to the total weight of the composition.
In a more preferred embodiment, the composition comprises:
(A)30-60 wt% of the thermoplastic polyamide;
(B) 30-60% by weight of the fiber reinforcement;
(C)1-8 wt% of the silicone block containing polymer;
(D)5-20 wt% of the flame retardant; and
(E)0.05 to 25 wt% of the at least one additional component;
wherein the weight percent (wt%) is relative to the total weight of the composition.
Suitably, the at least one additional component herein is one or more of the above inorganic fillers and additives.
The present invention also relates to a molded article made of the composition according to the invention or any of its specific or preferred embodiments as described above.
The composition according to the invention is suitable for use in a molded article, for example, a connector for an electronic device (e.g., a DDR connector), or a frame for an electronic device (e.g., a C-shaped frame), or a part of a frame for an electronic device, or an engine part (e.g., a crankshaft cover).
The moulded article according to the invention suitably comprises an extension section, wherein the extension section has a length (L) and a width (W) with a length/width ratio (L/W) of at least 5, preferably at least 10, and/or a width (W) and a thickness (T) with a width/thickness ratio (W/T) of at least 10, preferably at least 20.
The invention is further illustrated using the following examples and comparative experiments.
Material
Polyamide PA-6T/4T/66 copolymer with Tm of 325 ℃ and VN of 75ml/g
Glass fibers are used for standard grades of polyamide, chopped fibers, round, 10 μm (micrometers) in diameter
Flame retardant aluminium diethylphosphinate (Exolit OP1230)
Polymers containing silicone blocks
A polyester polysiloxane block copolymer comprising about 35% by weight of Polydimethylsiloxane (PDMS) blocks.
Additive package: standard stabilizers and mold release agents
Mixing
The flame retardant polyamide compositions of example I and comparative experiment a were prepared on a twin screw extruder. The temperature of the extruded melt is typically about 350 ℃ and therefore well above the melting temperature of the polyamide, 325 ℃. After melt mixing, the resulting melt was extruded into strands, cooled and cut into pellets. The compositions and test results have been summarized in table 1.
Injection moulding
The flame retardant polyamide composition was injection moulded into a suitable test mould using a standard injection moulding machine to form test bars according to ISO 5271A. The arrangement is such that the melt of the composition reaches a temperature of about 340 ℃. For the mechanical testing, test bars with a thickness of 4mm were produced. For UL 94 burn test, test bars with a thickness of 0.4mm were produced. The flame retardant and mechanical properties of the compounds (compositions) were measured using the test bars and the results of the tests are reported in table 1.
For the warpage test, a mold having a cavity for manufacturing a connector was used. For injection molding, the same conditions as described above for the ISO 5271A type test bar are used, and an injection gate (injection gate) is located at one end of the part. The molded product comprises an extension portion having the following dimensions: a length of about 140mm, a width of about 6mm, and a height of about 5 mm.
Test method
Viscosity number
The Viscosity Number (VN) was determined by the method according to ISO 307:2007-05(E) at a concentration of 0.5g/dL in 96% sulfuric acid solution.
Mechanical characteristics
The mechanical properties (tensile modulus [ MPa ], tensile strength [ MPa ], elongation at break [% ]) were measured in a tensile test at 23 ℃ and 5mm/min according to ISO 527.
Flame retardancy
Flame retardancy is measured according to Underwriters Laboratories (Underwriters Laboratories) test method UL 94 using 0.4mm test bars conditioned for 48 hours at 23 ℃, 50% relative humidity or 168 hours at 70 ℃.
Warp of
Warpage was measured on the product directly after molding and after undergoing a reflow temperature profile. For the reflow test, a standard Sony curve with a peak temperature of 260 ℃ was used.
The molded article was placed on one side of a flat surface having a width of 6mm so as to contact the surface at least two points. These points of contact are identified and used as reference points. The part was rotated on one of its 5mm sides. A reference line is drawn through the reference point by means of a laser beam. Six points are selected that are evenly distributed over the length of the molded article and the distance of the six selected points from the reference line is recorded. The mean and standard deviation of the six measurements were calculated.
The results for molded parts made with the compositions of example 1 and comparative example a are reported in table 1.
TABLE 1 compositions and test results of example 1(EX-1) and comparative experiment (CE-A).
The results show that the composition according to the invention (example 1) results in a molded product showing less warpage both when molded into shape and after reflow testing compared to the corresponding composition of comparative experiment a, which does not comprise a polymer comprising a silicone-containing block. In addition to the higher average warpage of CE-A, the standard deviation of warpage of CE-A is also higher. This indicates that the deformation of the molding of CE-A is also more irregular than the deformation of the molding of EX-1.
Claims (16)
1. A fiber reinforced polyamide composition comprising (a) a thermoplastic polyamide, (B) a fiber reinforcement, and (C) a silicone block containing polymer.
2. The fiber reinforced polyamide composition according to claim 1, further comprising (D) a flame retardant.
3. The fiber reinforced polyamide composition of claim 1 or 2, wherein the silicone block containing polymer comprises a copolymer of the formula- [ R [ ]2SiO]n-represents a silicone block having a degree of polymerization (n) in the range of 5-300.
4. The fiber reinforced polyamide composition of any of claims 1-3, wherein at least 20 weight percent of the silicone block containing polymer is comprised of polysiloxane.
5. The composition of any of claims 1-4, wherein the silicone block-containing polymer comprises a functionalized polydiorganosiloxane polymer, preferably comprising end groups functionalized with groups selected from amine groups, hydroxyl groups, epoxide groups, and carboxylic acid groups; or a polydiorganosiloxane block copolymer, preferably comprising a polydiorganosiloxane polyamide block copolymer, a polydiorganosiloxane polyurethane block copolymer, a polydiorganosiloxane polyether block copolymer, a polydiorganosiloxane polyester block copolymer, or a polydiorganosiloxane polycarbonate block copolymer.
6. The composition of any of the above claims, wherein the thermoplastic polyamide comprises a semi-crystalline semi-aromatic polyamide, an amorphous semi-aromatic polyamide, or a semi-crystalline aliphatic polyamide, or any combination thereof.
7. The composition of any of the above claims, wherein the thermoplastic polyamide comprises a semi-crystalline polyamide having a melting point of at least 270 ℃.
8. The composition of any of the above claims, wherein the fiber reinforcement comprises glass fibers, preferably non-round glass fibers having an aspect ratio W/T of width to thickness of at least 1.5 in cross-section.
9. The composition of any of the preceding claims, wherein the flame retardant comprises a halogen-free flame retardant, preferably a nitrogen (N) -or phosphorus (P) -containing halogen-free flame retardant, or a nitrogen (N) -and phosphorus (P) -containing halogen-free flame retardant, preferably a metal phosphinate or metal diphosphinate, or a combination thereof.
10. The composition of any of the above claims, comprising
(A)30-70 wt% of the thermoplastic polyamide;
(B)20-60 wt% of the fiber reinforcement;
(C)0.5 to 10 weight percent of the silicone block containing polymer;
(D)5-25 wt% of the flame retardant; and is
Wherein the weight percentages (wt%) are relative to the total weight of the composition.
11. Composition according to any one of the preceding claims, comprising at least one further component in an amount ranging from 0.01 to 40% by weight, preferably from 0.05 to 25% by weight, relative to the total weight of the composition.
12. The composition of any one of the preceding claims, wherein the composition consists of:
(A)30-70 wt% of the thermoplastic polyamide;
(B)20-60 wt% of the fiber reinforcement;
(C)0.5 to 10 weight percent of the silicone block containing polymer;
(D)0-25 wt% of the flame retardant; and
(E)0.01 to 40 wt% of at least one additional component;
wherein the weight percentages (wt%) are relative to the total weight of the composition.
13. Composition according to any one of the preceding claims, in which the said composition comprises less than 50% by weight of the said thermoplastic polyamide (A) and 0.5-10% by weight of the said silicone block-containing polymer (C), relative to the total weight of the said composition.
14. A molded part, wherein the molded part is made from the composition of any of the preceding claims.
15. A moulded article according to claim 18 which is a connector for an electronic device, or a frame for an electronic device, or a part of a frame for an electronic device, or an engine part.
16. A moulded article according to claim 18 or 19 comprising an extension section, wherein the extension section has a length and a width with a length/width ratio of at least 5, preferably at least 10, and/or has a width and a thickness with a width/thickness ratio of at least 10, preferably at least 20.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP18187218 | 2018-08-03 | ||
| EP18187218.5 | 2018-08-03 | ||
| PCT/EP2019/069435 WO2020025350A1 (en) | 2018-08-03 | 2019-07-18 | Fiber reinforced polyamide composition and molded part made thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112533993A true CN112533993A (en) | 2021-03-19 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980051050.3A Withdrawn CN112533993A (en) | 2018-08-03 | 2019-07-18 | Fiber-reinforced polyamide composition and molded article made therefrom |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN112533993A (en) |
| TW (1) | TW202018011A (en) |
| WO (1) | WO2020025350A1 (en) |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02255764A (en) | 1989-03-28 | 1990-10-16 | Unitika Ltd | Method for preventing warpage of crystalline polyamide molded article |
| JPH10130494A (en) | 1996-10-29 | 1998-05-19 | Unitika Ltd | Polyamide resin composition and vehicle parts for holding miller and body parts for electrical equipment and appliance using the same |
| DE19933901A1 (en) | 1999-07-22 | 2001-02-01 | Clariant Gmbh | Flame retardant combination |
| JP4511669B2 (en) | 2000-02-18 | 2010-07-28 | 旭化成ケミカルズ株式会社 | Reinforced polyamide resin composition |
| US20100227122A1 (en) | 2006-01-13 | 2010-09-09 | Teruhisa Kumazawa | Polyamide Resin Composition for Portable Electronic Device and Molded Article for Portable Electronic Device |
| CN101535409B (en) | 2006-11-20 | 2013-03-20 | 三井化学株式会社 | Flame-retardant polyamide composition |
| WO2008120703A1 (en) | 2007-04-03 | 2008-10-09 | Unitika Ltd. | Glass fiber reinforced polyamide resin composition |
| EP2186861A1 (en) * | 2007-09-07 | 2010-05-19 | Unitika, Ltd. | Flame-retardant glass-fiber-reinforced polyamide resin composition |
| US20110152420A1 (en) * | 2009-12-22 | 2011-06-23 | Mark Elkovitch | Poly(arylene ether)/polyamide compositions, methods, and articles |
| JP5979846B2 (en) * | 2011-10-26 | 2016-08-31 | 大塚化学株式会社 | RESIN COMPOSITION FOR REFLECTOR AND REFLECTOR |
| US20140066551A1 (en) * | 2012-08-30 | 2014-03-06 | Sabic Innovative Plastics Ip B.V. | Glass-filled polyamide composition and article |
| US8592549B1 (en) * | 2012-12-05 | 2013-11-26 | Sabic Innovative Plastics Ip B.V. | Polyamide composition, method, and article |
| US20140171575A1 (en) * | 2012-12-14 | 2014-06-19 | Sabic Innovative Plastics Ip B.V. | Thermally conductive flame retardant polymer compositions and uses thereof |
| JP6136334B2 (en) | 2013-02-14 | 2017-05-31 | 東洋紡株式会社 | Flame retardant polyamide resin composition |
| JP6249711B2 (en) * | 2013-07-08 | 2017-12-20 | ユニチカ株式会社 | Semi-aromatic polyamide resin composition, molded body formed by molding the same, and sliding member |
| WO2015066138A1 (en) * | 2013-10-29 | 2015-05-07 | Dow Corning Corporation | Flame retardant thermoplastic polymer compositions |
-
2019
- 2019-07-18 WO PCT/EP2019/069435 patent/WO2020025350A1/en active Application Filing
- 2019-07-18 CN CN201980051050.3A patent/CN112533993A/en not_active Withdrawn
- 2019-07-26 TW TW108126588A patent/TW202018011A/en unknown
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| Publication number | Publication date |
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| WO2020025350A1 (en) | 2020-02-06 |
| TW202018011A (en) | 2020-05-16 |
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