MX2008000016A

MX2008000016A - Reinforcing yarns and composites with an improved fire-resistance

Info

Publication number: MX2008000016A
Application number: MX/A/2008/000016A
Authority: MX
Inventors: Gasca Jeanphilippe; Chivas Carine; Bergeret Anne; Lopezcuesta Josemarie
Original assignee: Saintgobain Vetrotex France Sa Societe Anonyme
Priority date: 2005-07-06
Filing date: 2008-01-07
Publication date: 2008-10-03

Abstract

The invention relates to a composition for reinforcing yarns, characterised in that it comprises at least one additive that can modify the matrix/yarn interface in order to improve the fire-resistance of the matrix/yarn composite. The invention also relates to the yarns and composites obtained.

Description

THREADS AND REINFORCEMENT COMPOSITIONS WITH IMPROVED FIRE RESISTANCE FIELD OF THE INVENTION The present invention relates to strands (or fibers) capable of reinforcing organic and / or inorganic materials, and also to the obtained reinforced products (or compositions), those strands and those reinforcing compositions have better resistance to dust. The present invention also relates to the composition used to coat those strands and to the process for making those strands.

BACKGROUND OF THE INVENTION The present invention relates in particular to glass reinforcing strands that can be obtained by mechanically attenuating, at high speed, (up to a few tens of meters per second), molten glass flows flowing out of holes in the glass. the base of one or more. These strands are attenuated in the form of filaments, the filaments being coated, before being assembled into strands, and with a composition, called sizing composition, which is intended in particular to protect the strands against abrasion, to allow the strands to be combined with the matrix (one or more organic materials and / or one or more inorganic materials) to be reinforced, etc. Although the glass strands have remarkable properties, which are found in the composite products produced, they nevertheless have a negative effect with respect to the fire resistance of those compositions, possibly facilitating the propagation of the flames within the compositions. The conventional fire retardants incorporated in the matrix do not really eliminate this object since the resistance values reached in this case are still insufficient, in particular the values are below the level reached in the presence of reinforcement strands. The main purpose of the present invention is to solve this problem and it has been found that adding to the sizing composition of a component is not necessarily so. A fire retardant recognized but acting on the interfaces of the threads / matrices within the compositions produced, thereby retarding ignition or accelerating self-extinction, improves the fire resistance of the composition without however damaging its properties (especially its mechanical properties) or the processing of the reinforcing strands.

THE INVENTION The first objective of the present invention is therefore a composition, in particular a sizing composition, used to require reinforcing strands, in particular glass strands, characterized in that it includes at least one additive capable of acting (or modifying) the interfaces. strand / matrix, so as to improve the fire resistance of the composition of the strands / reinforcement matrix, especially delaying the ignition and / or accelerating the self-extinction, without therefore damaging the mechanical properties of the composition or the processing of the fibers. threads. The delay of ignition and / or acceleration of self-extinction will result in at least one phenomenon occurring essentially at the interface of the strands / matrix and preferably leading to a reduction in heat transfer at the interface, especially by the formation of a carbon layer, the additive being for example the carbon donor or acting with an oxidizing agent which cuts the chains of the matrix at the interface and promotes cross-linking, or interaction with a flame retardant of the matrix, etc., without being tied to any material with respect to those different possible modes of action. The additive or additives capable of modifying the interface strands / matrix to improve the fire resistance of the composition of strands / matrix (without damaging therefore the mechanical properties of the processing) can be chosen especially from: nitrates, such as potassium nitrate (KNO3) or guanidine nitrate; alcohols and their derivatives, such as pentaerythritol and its derivatives, particularly dipentaerythritol, tripentaerythritol, ethoxylated pentaerythritol, propoxylated pentaerythritol, ethoxylated / propoxylated pentaerythritol, or sorbitol (or D-glucitol); and phosphorus derivatives or phosphoric acid derivatives, organophosphorus, phosphate or organophosphinate compounds of cyclic ester, such as ammonium polyphosphate, guanidine phosphate, 1, 2, 3-dioxaphosphorin or ammonium pyrophosphate, these or more additives being preferably chosen between nitrates, potassium nitrate (KNO3) or guanidine nitrate (with nitrate being preferred as potassium nitrate), and / or between alcohols (and their derivatives) of the sorbitol type. or pentaerythritol derivatives, preferably (notably when the reinforcing strands are intended to be cut or cut) between ethoxylated pentaerythritol, propoxylated pentaerythritol, ethoxylated / propoxylated pentaerythritol and. sorbitol, and particularly preferably between ethoxylated pentaerythritol and sorbitol.

The additives chosen according to the invention normally do not form part of products conventionally classified as fire retardants, and for example would have no effect against fire if they were incorporated, in particular alone to the same reason, in the matrix without more than threads. As indicated above, their action is exerted essentially at the thread / matrix interface (in particular at the sizing / strand and / or sizing / matrix interfaces), with the compounds being able to interact, where appropriate, at the interface, with the matrix and / or fire retardants of the matrix and / or with other components of the sizing. It should be noted that the composition according to the invention does not advantageously contain red phosphorus, antimony oxide or halogenated compounds, as the latter being also dangerous for the environment. Preferably, the additives capable of modifying the strands / matrix according to the invention are soluble, dispersible or emulsifiable in water and / or in (the rest of) the composition. Since the composition according to the invention is generally an aqueous composition, the solids content of the composition is in this case preferably between 1 and 20%. by weight of the composition (the composition comprising between 80 and 99% by weight of water), especially between 2 and 10% by weight. In other embodiments, the composition according to the invention may not contain water or may include other solvents. The content of additives capable of modifying the strand / matrix interface according to the invention is generally between 1 and 60% and preferably between 2 and 40% by weight of the solids content of the composition. The composition (preferably the sizing composition) may also contain at least one coupling agent, generally for coupling the reinforcing strands (particularly the glass strands) to the matrix to be reinforced. This coupling agent can be chosen especially from silanes, titanates and zirconates, and is preferably chosen from silanes (in particular aminosilanes, epoxysilanes, etc.). The content of coupling agents is then preferably between 1 and 50% by weight, advantageously between 2 and 20% by weight and particularly preferably between 5 and 15% by weight of the solids content of the composition. The composition can also contain at least one binding agent, (film former), said agent generally acting on the processing capacity of the strand (stiffness, interfilament cohesion, etc.) and being chosen for example from polyurethanes, epoxy resins, acrylic copolymers, polyvinyl acetates, and polyolefin emulsions, the content of the binding agent being (film former) as the case may be (when present) of between 10 and 90% and preferably between 20 and 80% by weight of the solids content of the composition. Preferably, the composition includes at least one binding agent capable of fixing the additive according to the invention to the surface of the strands so that it remains at the strand / matrix interface, this film former being advantageously in the form N of a polyurethane and being chosen in particular so that it is so little soluble in the matrix or does not diffuse excessively towards the interfaces. For example, a polyurethane is intended to be crosslinked after the deposition of the composition on the strands (for example during a drying operation), this polyurethane being highly crosslinkable (in particular having functional groups capable of crosslinking, such as isocyanate groups within the actual polymer chain) or being mixed with a crosslinking agent (representing for example about 2 to 50% by weight of the polyurethane / crosslinking agent mixture), such as a polyisocyanate or a polycarbo-diimide, these functional groups possibly being crosslinking agents blocked by a blocking agent (which can for example be unblocked by counter treatment), such as caprolactam or butanon oxime. Where appropriate, several may be used agents for forming a different bonding film (particularly polyurethane) or only a bonding agent that satisfies the different functions. For example, it is possible to use at least one binding agent, which promotes especially good binding properties (and / or allow, where appropriate, maintenance of the additive, and possibly the other components, on the strands, as mentioned above. ), and optionally another bonding agent capable of protecting the reinforcing strands and / or making their processing easier. Finally, the composition (in particular the sizing composition) according to the invention can include at least one other standard agent (generally up to 20% by weight of its solid content), this agent chosen for example as a lubricant (for example, a ethoxylated fatty alcohol ester), emulsifiers or surfactants (for example, stearyl alcohol containing 20 mol of ethylene oxide), antistatic agents, antifoaming agents, wetting agents, textile agents, etc. As mentioned above, the composition generally includes at least one solvent, especially water. Where appropriate, certain active components may have already been dissolved or dispersed in a solvent during their addition to the mixture which the composition and / or the solvents have to form. they can be added to the mixture after the active components to obtain the viscosity and proportions that are usually required for the deposition of filaments. A preferred sizing composition according to the invention has for example the following formulation: The present invention also relates to reinforcing strands (advantageously glass strands) re-coated with the previous composition, making it possible for the strands to be in various forms, such as continuous strands, cut strands, braids, ribbons, meshes, etc. The content of the deposited composition (or loss after ignition) is advantageously from 0.1 to 3% by weight, preferably from 0.2 to 1.5% by weight of the strands. The composition according to the invention can be deposited in one or more steps on filaments (which have to form the strands) and / or on the reinforcing strands. The compositions obtained from the strands generally comprise at least one organic material and reinforcing strands, at least some of the reinforcing strands being the strands according to the invention. An object of the present invention is also a process for the manufacture of glass strands coated with the composition according to the invention, in which a multiplicity of molten glass strands, flowing out of a multiplicity of holes in the base of one or more matrices (or spinners), are stretched (or attenuated at speeds of several meters per second to several tens of meters per second) in the form of one or more sheets of continuous filaments (generally with a diameter of between 5 and 24). μta.). And then the filaments are mounted. in one or more strands that are collected on a mobile support, the process consisting of the deposition, on the surface of the filaments while they are stretched and before the filaments are mounted on one or more strands, in at least some of the composition of sizing according to the invention, the strands being, where appropriate, coated with the complete composition at the end during the collection of the strands. The strands can be collected from several ways In particular, they can be cut, either after forming by the device used to stretch them, or in a subsequent operation, or they can also be wound on rotating supports (to form coils such as skeins, stocks, cakes, etc.), or else can be distributed on mobile conveyors (to form for example meshes or veils). Where appropriate, the strands can be dried (for example by infrared radiation, hot air, high frequency, etc.), since the water can damage the good adhesion between the strands and the materials to be reinforced, and / or can be treated with heat (at temperatures that fluctuate possibly up to 200 ° C, for example) to allow , where appropriate, cure and / or reticular all or part of the sizing. It should be noted in the present invention that the term "glass strands" means glass-based strands, ie not only strands formed only of glass filaments but also strands formed of glass filaments and organic filaments, especially thermoplastic filaments. In the latter case, during the attenuation of the glass filaments, the organic filaments are extruded and captured simultaneously with these (or also the organic strands, from eg packages, are supplied simultaneously), the paths followed by the glass filaments Y the filaments. { or strands) organic converging with each other before the filaments are mounted on at least one mechanically captured composite strand. The object of the present invention is also a composition comprising at least one organic material and at least threads as defined above. The organic material is advantageously a thermoplastic, especially chosen from polyamides, thermoplastic polyesters, such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), polyolefins, polyacetals, polycarbonates, etc. The mouldable matrix composition used to maintain the composition by molding may also contain (in addition to the material to be reinforced and the reinforcing strands) at least one flame retardant agent (e.g., cyanurate such as melamine cyanurate and / or a compound of organophosphorus, such as melamine pyrophosphate) and / or can in particular contain fillers that provide good mechanical strength and / or dimensional stability to the composition (for example mineral fillers of the type comprising mica, talc, etc.). A moldable matrix composition according to the invention can advantageously have the following formula: 20 to 95% by weight of organic materials; l to 60%, especially from 5 to 40% and preferably from 10 to 30% by weight d at least one retarding agent > of the flames; l to 60% by weight, and of. preferably from 10 to 40% by weight, of strands prepared according to the invention; and - 0 to 50% by weight inorganic / mineral fillers.

DETAILED DESCRIPTION OF THE INVENTION The following example illustrates the present invention without, however, limiting its scope: A sizing composition having the following formulation by mixing its different ingredients in water.

The glass strands were manufactured by stretching filaments of molten glass from a spinner, the prior sizing composition being deposited before the filaments were grouped together into strands. The obtained strands were then cut directly under the spinner and a mouldable composition having the following formulation was prepared: A molded part composed of the above mouldable composition was then obtained by extrusion followed by injection molding.

Then, each of the following tests was carried out: LOI test (according to ISO 4589-2 / 1996F standard): Epiradiateur test (according to NFP standard 92-505) and the calorimeter test (according to the ASTM E1354 standard). The tests were carried out on specimens produced according to the present example (results of the "fiber (KNO3)" below) and on comparative specimens obtained by replacing the strands according to the present example with strands that had been prepared with the same composition. but without KN03 (results of the "control fiber" below). The results are given in the following table.

LOI test consisted of determination Oxygen concentration in an oxygen / nitrogen mixture that allowed the combustion of a material at a given time (180 seconds) and over a given length (50 'mm). The results of this test show that it is more difficult to maintain combustion in the case of products according to the invention. Similarly, in the case of the Epiradiateur test, it is clearly evident that a much longer time is required for the products according to the invention to catch fire and that these products extinguish much more rapidly. Finally, the cone calorimeter test shows that the energy released by combustion is much lower in the case of the products according to the invention. In addition, it should be noted in the following table that these improvements did not deteriorate the mechanical properties of the compositions, the values of mechanical strength being obtained from the same order if the strands of the example or the comparative strands were used (tensile strength values obtained from according to ISO 527-2 standard and Charpy impact resistance values according to ISO standard 179-1).

The strands and composite reinforcemproducts produced according to the invon can be used in various applications, for example in connectors, in the manufacture of electrical and electronic packages, etc.

Claims

CLAIMS 1. Composition, in particular sizing composition, for coating strands capable of reinforcing a matrix to obtain a composition, characterized in that it includes at least one additive capable of acting on the interfaces of strands / matrix to improve the fire resistance of the composition . Composition according to claim 1, characterized in that the additive or additives capable of modifying the strand / matrix interface are chosen from: nitrates, such as potassium nitrate (KN03) or guanidine nitrate; alcohols and their derivatives, such as pentaerythritol and its derivatives, particularly dipentaerythritol, tripentaerythritol, ethoxylated pentaerythritol, propoxylated pentaerythritol, ethoxylated / propoxylated pentaerythritol, or sorbitol (or D-glucitol); and phosphorus derivatives or phosphoric acid derivatives, organophosphorus compounds, phosphates or cyclic ester organophosphinates, such as ammonium polyphosphate, guanidine phosphate, 1, 2, 3-dioxaphosphorin or ammonium pyrophosphate. Composition according to any of claims 1 and 2, characterized in that it does not contain red phosphorus, antimony oxide or compounds halogenated 4. Composition according to one of claims 1 to 3, characterized in that it contains at least one coupling agent, chosen mainly from silanes such as aminosilanes and epoxysilanes. Composition according to one of claims 1 to 4, characterized in that it contains at least one binding agent selected from polyurethanes, ethoxides, acrylic copolymers, vinyl acetates and polyolefin emulsions. Composition according to one of claims 1 to 5, characterized in that it includes at least one binding agent, such as a polyurethane, capable of fixing the additive to the surface of the strands, so that the strand / matrix interface remains. Composition according to one of claims 1 to 6, characterized in that it includes at least two different polyurethane bonding agents. • 8. Composition according to one of claims 1 to 7, characterized in that it has the following formulation: 9. Reinforcing strands, particularly glass strands, coated with the sizing composition according to one of claims 1 to 8. 10. Process for making glass strands in which a multiplicity of glass strands multiplicity of molten, flowing glass strands outward from a multiplicity of holes in the base of one or more dies, they are stretched in the form of one or more sheets of continuous filaments and then the filaments are mounted on one or more strands that are collected on a mobile support, the process in the deposition, on the surface of the filaments while they are stretched and before the filaments are mounted in one or more strands, in at least some of the sizing composition according to one of claims 1 to 8, the strands being where appropriate, coated with the complete composition at least during the collection of the strands. 11. Moldable composition, comprising less threads, according to claim 9. 12. Composition according to claim 11, characterized in that it also has at least one flame retardant agent and / or at least fillers. 13. Composition according to any of claims 11 and 12, characterized in that it has the following formulation: - 20 to 95% by weight of organic materials; l to 60%, especially from 5 to 40% and preferably from 10 to 30% by weight of at least one flame retardant agent; - l to 60% by weight, and preferably from 10 to 40% by weight, of strands prepared according to the invention; and - 0 to 50% by weight inorganic / mineral fillers. 14. Composite part with improved fire resistance, obtained from the composition according to one of claims 11 to 13 and / or including at least threads according to claim 9.