CN116141787A - Flame-retardant laminated film with improved tearing strength - Google Patents

Abstract

The invention relates to the technical field of new materials, in particular to a flame-retardant and fire-retardant laminated film for improving tearing strength. The structure of the flame-retardant and fire-retardant laminated film comprises: a first film; a silica cloth; a second film; and an adhesive compound comprising an inorganic filler, wherein: the adhesive is positioned between the first layer and the second layer and between the second layer and the third layer, and the silica cloth is subjected to dip-dyeing treatment of the adhesive; the silica cloth is made by weaving high-purity silica roving according to the original structure of woven fabric, the density of warp yarn and weft yarn is 15-30 pieces/cm, and the warp yarn and weft yarn are separated by 4-10mm in the radial direction and the weft direction, and the reinforcing rib yarn is adopted to replace the high-purity silica roving. The invention improves the tearing strength of the product on the basis of retaining other functions of the flame-resistant burning-through coating of the final product, including the performances of weight per unit area, tensile property, water absorption, flame-resistant burning-through property (fire resistance), 12S vertical burning property (flame retardance) and the like.

Description

Flame-retardant laminated film with improved tearing strength

Technical Field

The invention relates to the technical field of new materials, in particular to a flame-retardant and fire-retardant laminated film for improving tearing strength.

Background

Thermal and acoustic insulation materials are commonly used in aircraft fuselages to reduce noise from outside into the cabin and to maintain a comfortable temperature within the cabin. The thermal and acoustic insulation material may (first) create a barrier to prevent or reduce heat/flame transfer and (second) attenuate ambient noise to ensure proper cabin and cockpit comfort and conversation volume.

The Federal Aviation Administration (FAA) mandates that thermal and acoustic insulation materials used in commercial aircraft must be able to prevent burn-through and flame propagation. At present, heat and sound insulation materials, including films and inner cores, must be tested according to Federal aviation regulations No. FAR 25.856 (a) and (b).

In the past, glass fiber cotton encapsulated by plastic dampproof coating has the two functions. The coating film consists of terylene (PET), polyvinyl fluoride (PVF) and a small amount of polyimide. While these materials are necessary to meet vertical bunsen burner detection, some materials may propagate flames under certain conditions.

For this reason, the applicant filed chinese invention patent (publication No. CN105593016a, publication No. 2016-05-18) discloses that a typical example of the flame retardant and fire resistant laminated film comprises a glass layer, a first film, a second film and an adhesive. The glass layer may comprise a high purity silica cloth. The first film and the second film need to meet flame retardant requirements. The adhesive may contain at least one inorganic filler to obtain optimal fire-blocking properties. The glass layer, the first film and the second film may be bonded together by adhesive and thermal lamination.

The principle of fabric tearing is illustrated in fig. 7, where a plurality of yarns are gathered in a tearing triangle, and the force required for tearing can be regarded as the force required to break the yarns in this triangle. The amount of tear strength is therefore dependent mainly on two factors, one being the single yarn strength of the fabric, which depends on the fabric material, yarn count, twist, spin, and strength retention of dyeing and finishing, and the second being the number of yarns that can slip in the tear triangle, which depends on the fabric density and friction between the yarns. Chinese patent application (publication No. CN105593016A, publication No. 2016-05-18) discloses that after the fabric is compounded with the film by the adhesive, the yarns are limited by the adhesive, the friction force is increased, the yarns are difficult to slide, the yarns in the triangular region are torn, and the tearing strength is lost.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a flame-retardant and fire-retardant laminated film with improved tearing strength, and the material and yarn count of yarns are changed in a reinforcement mode, so that the strength and deformation capability of single yarns can be improved, and the number of yarns in a tearing triangular area can be further increased, thereby improving the tearing strength. The flame-retardant and fire-retarding laminated film can be used for a heat and sound insulation system of a commercial aircraft or used for other aspects of flame retardance and fire resistance required by the commercial aircraft at present. The flame-retardant laminated film can meet or even exceed the requirements and regulations of the current federal aviation administration on the flammability standard of heat/sound insulation materials of transportation airplanes.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a flame retardant, fire retardant laminate film having improved tear strength, the structure of the flame retardant, fire retardant laminate film comprising:

a first layer comprising a first film;

a second layer comprising silica cloth;

a third layer, the composition of which is a second layer of film; and

an adhesive comprising an inorganic filler, wherein: the adhesive is positioned between the first layer and the second layer and between the second layer and the third layer, and the surface of the first layer or the third layer, and the silica cloth is subjected to dip-dyeing treatment of the adhesive;

the silica cloth is made by weaving high-purity silica roving according to the original structure of woven fabric, the density of warp yarn and weft yarn is 15-30 pieces/cm, and the warp yarn and weft yarn are separated by 4-10mm in the radial direction and the weft direction, and the reinforcing rib yarn is adopted to replace the high-purity silica roving.

Preferably, the reinforcing rib yarn adopts one or more of nylon, terylene, aramid fiber, carbon fiber, high-strength polyethylene fiber, polyphenylene sulfide fiber, polyimide fiber, high-strength glass fiber and high-purity silicon dioxide roving with the linear density of more than 2 times.

Preferably, the material of the first film is selected from one or more of a series of materials comprising: a fluoropolymer; a silicon polymer; polyether sulfone; polyether ether ketone; polyaryletherketone; polysulfone; a polyetherimide; polyetherketoneketone; polyphenylene sulfide; polyarylsulfone; and (3) an aluminum film.

Preferably, the material of the second film is selected from one or more of a series of materials comprising: a fluoropolymer; a silicon polymer; polyether sulfone; polyether ether ketone; polyaryletherketone; polysulfone; a polyetherimide; polyetherketoneketone; polyphenylene sulfide; polyarylsulfone; and (3) an aluminum film.

Preferably, the silica roving is bundled into a plurality of strands, each strand having a linear mass density of between 10 and 25 tex.

Preferably, the inorganic filler is selected from one or more of antimony trioxide, mica, vermiculite, ceramic fibers, titanium dioxide, fumed silica and silica ultrafine fibers; the mesh size of the inorganic filler is between 100 and 600 mesh.

Preferably, the silica cloth has an area weight of 45-260 grams per square meter.

Preferably, the first and second films have a thickness of between 3 and 9 μm.

Preferably, the adhesive layer has an areal weight of between 5 and 20 grams per square meter.

Preferably, the area weight of the flame retardant and fire resistant laminate film is between 67 and 339 grams per square meter.

By adopting the technical scheme, the invention improves the tearing strength of the product on the basis of keeping other functions of the flame-resistant and fire-penetrating coating layer (flame-retardant and fire-retardant composite film) of the final product, including the performances of weight per unit area, tensile property, water absorption, flame-resistant and fire-penetrating property (fire-retardant), 12S vertical burning property (flame retardance) and the like. Meanwhile, the reinforcement mode of the invention is that the reinforcement mode is in the fabric layer and is integrated with the fabric, namely, the reinforcement mode is integrated with the fire-resistant layer, and the product processing is more convenient.

Drawings

FIG. 1 is a cross-sectional detail view of a flame retardant, fire retardant laminate film of the present invention.

Fig. 2 is a top view of a plain weave glass cloth according to one embodiment of the present invention.

Fig. 3 is a cross-sectional view of a flame retardant adhesive in one embodiment of the invention.

Fig. 4 is a photograph of the product of comparative example 1.

Fig. 5 is a photograph of the product of example 1.

FIG. 6 is a photograph of the product of comparative example 2.

Fig. 7 is a schematic diagram of fabric tearing.

Detailed Description

The invention will be described in further detail with reference to the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation is given, but the scope of protection of the present invention is not limited to the following embodiments.

Fig. 1 is a sectional detail view of a flame retardant and fire retardant laminate film 100. The flame retardant, fire retardant laminated film 100 may be used in packaging films for sound and heat insulating materials in various vehicles. For example, the flame retardant and fire resistant laminated film 100 may be used in a variety of vehicles including, but not limited to, aircraft, trains, and ships. The laminate film 100 comprises a silica cloth layer 102, an adhesive 104, a first film 106, and a second film 108. And a layer of adhesive 104 is also provided on the outside of the surface of the first film 106 or the second film 108 for heat sealing. In one example, the silica cloth layer 102 may be a high temperature resistant high purity SiO2 fiberglass cloth, which is a multi-strand woven silica (SiO 2) cloth 110, as shown in fig. 2.

Generally, a plurality of high purity silica filaments of a preselected diameter may be bundled into a single silica roving 110. In one example, each filament in each silica roving 110 may have a diameter of 6-20 μm. The number and diameter of the monofilaments ultimately determine the linear mass density (units: tex (g/1000 m)) of the silica roving 110. The silica roving 110 is a 92-99.98% pure silica filament.

The silica cloth layer 102 may be formed by a braiding process, in one example a planar weaving is performed. Planar weaving may be referred to as plain weave, linen weave, or plain weave. In planar weaving, the warp and weft yarns may form a simple cross.

The purity of the silica roving is achieved in 2 ways, and the first way is to use high-purity quartz sand for wiredrawing.

The second way is acid washing, and after the silica cloth layer 102 is woven, the silica cloth layer 102 may be immersed in an acidic solution. The silica cloth layer 102 may be immersed in an acidic solution until the silica filaments have reached a purity of at least 92%. The acidic solution may include, but is not limited to: h2SO4 solution, hydrochloric acid solution, hydrogen bromide solution, nitric acid solution, and phosphoric acid solution.

As shown in FIG. 2, in one example, the silica cloth is made by weaving silica roving with a weave of woven fabric, the warp and weft have a density of 15-30 pieces/cm, and the warp and weft are separated by 4-10mm in the radial and weft directions by using a reinforcing rib yarn 111 instead of the silica roving 110. The reinforcing rib yarn 111 is one or more of nylon, terylene, aramid, carbon fiber, high-strength polyethylene fiber, polyphenylene sulfide fiber, polyimide fiber, high-strength glass fiber and silica roving 110 with linear density more than 2 times.

Fig. 3 is a cross-sectional detail view of a flame retardant adhesive 104 in one embodiment of the invention. The adhesive 104 may include a filler 120. In one example, the adhesive 104 may be selected from a range of materials including, but not limited to, polymers, copolymers, and/or terpolymers. Any polymer selected may have inherent flame retardancy or may be modified with a flame retardant to be flame retardant. The polymer may include, but is not limited to, polyvinyl chloride, polyethylene-vinyl chloride, polyacrylate, polyurethane, polyacrylamide, and the like. Flame retardants may include, but are not limited to, melamine derivatives, resins of the melamine/formalin type, phosphorus compounds, phosphate esters, borate esters, and halogen compounds.

In one example, the adhesive 104 may be a chemically non-reactive adhesive. For example, the adhesive 104 may be, but is not limited to, an adhesive emulsion. In one example, the adhesive 104 may be a high molecular suspension adhesive with the high molecular (polymer) suspended in a solvent (e.g., water). For example, the adhesive 104 may be soluble in water or in a solvent. Generally, as the solvent evaporates, the adhesive will harden.

In one example, the adhesive 104 may be achieved by immersing the silica cloth layer 102 in a container containing the liquid adhesive 104. In another example, the adhesive 104 may be pressed into the silica cloth layer 102 by one or more press rolls.

As previously described, the adhesive 104 may be mixed with an inorganic filler. The inorganic filler 120 may comprise 5-15% by weight of the solids of the adhesive 104. In one example, the filler 120 comprises 8-11% by weight of the solids of the adhesive 104. The choice of inorganic filler may be determined by whether or not the fire resistance is enhanced. The inorganic filler 120 may fill small holes of the glass layer 102 to enhance the flame penetration resistance. The inorganic filler 120 may be, but is not limited to, a sheet silicate mineral (e.g., phyllosilicate). For example, antimony trioxide, mica or vermiculite may be used. Vermiculite can fill small holes of glass fabric, can obviously expand when heated, and enhances flame penetrability.

The particle size of the filler 120 is between 100-600 mesh. Within this range, the filler 120 has good filling ability and the silica cloth layer after filling has a smooth surface. In some cases, high temperature resistant microfibers (including but not limited to ceramic fibers or silica rovings) may be used as the filler 120 in the adhesive 104.

In one example, the adhesive 104 may be a water-based polyethylene-vinyl chloride emulsion. Such an emulsion may use antimony trioxide as filler 120. In another example, the emulsion employs mica as the filler 120.

In general, the adhesive 104 and filler 120 may be impregnated into the silica cloth layer 102 by immersing the glass layer 102 in the adhesive 104. For example, the silica cloth layer 102 may be introduced into a tank containing the adhesive 104. In one example, the silica cloth layer 102 is introduced into a tank filled with a filler-mixed adhesive 104 for impregnation. After exiting this tank, the silica cloth layer may pass through a pair of press rolls. The pressure roller may be used to control the amount of adhesive applied to the silica cloth layer 102. The impregnated silica cloth layer may then be transferred to a heating device for drying.

The first film 106 and the second film 108 may be a type of high temperature resistant polymeric material. Such materials include, but are not limited to, fluoropolymers, silicon polymers, polyethersulfones (PES), polyetheretherketones (PEEK), polyaryletherketones (PAEK), polysulfones (PSF), polyetherimides (PEI), polyetherketoneketones (PEKK), polyphenylene sulfides (PPSD), and Polyarylsulfones (PAS).

In some examples, the first film 106 and the second film 108 may be aluminum films, such as pure aluminum, aluminum alloys, and aluminum oxides. Typically, the thickness of the first and second films 108 ranges from 3 to 9 microns. It is noted that the thickness of the first film 106 and the second film 108 may be increased or decreased without departing from the scope of the present invention.

Generally, as shown in FIG. 1, an impregnated silica cloth layer may be sandwiched between a first film 106 and a second film 108. In certain implementations, the surfaces of the first film 106 and the second film 108 may be coated with the adhesive 104. In particular cases, one can prepare a first film 106 and a second film 108 of type 108, respectively, from a fire-blocking polymer. It is also possible to prepare the first film 106 from a fire resistant polymer and the second film 108 from aluminum.

Example 1

In this embodiment, the silica cloth layer 102 may include plain weave silica rovings, which are greater than 97% pure silica rovings. The density of warp yarns is 24 pieces/cm, the density of weft yarns is 23 pieces/cm, the original warp yarns are replaced by reinforcing rib yarns 111 at every 14 pieces of single silicon dioxide roving 110 in the radial direction, and 13 pieces of reinforcing rib yarns 111 are replaced by the original weft yarns at intervals in the weft direction; the rib yarn 111 uses a silica roving 110 having a linear density 2 times that of the original warp and weft yarns. The silica cloth layer 102 may have a weight per unit area of 59.6 grams per square meter. The adhesive 104 contained 90% vinnol 2752 (ethylene-vinyl chloride copolymer) aqueous adhesive, 5% water repellent, 1% z6040 silane coupling agent, 0.5% dispersant and 3.5% 300% platy mica filler.

The silica cloth layer 102 may also be impregnated with an adhesive 104. The impregnated silica cloth layer 102 may be dried by passing the silica cloth layer 102 through an oven. The silica cloth layer 102 has a controlled impregnation basis weight of about 64.6 grams per square meter.

The first film 106 and the second film 108 may constitute a Polyetherketone (PEEK) film having a thickness of 6 microns. The first film 106 and the second film 108 may be coated with an adhesive solution on the surface as the silica cloth layer 102. In general, the first film 106 and the second film 108 may be air dried in hot air after the adhesive 104 is applied. Typically, the coating weights of the first film 106 and the second film 108 may be controlled to about 8 grams per square meter. The impregnated silica cloth layer 102 may be sandwiched between the first film 106 and the second film 108 and fused together by a roll press at a pressure of 50 psi and a temperature of 150 degrees celsius.

Example 2

In this example, nylon fiber was used instead of the reinforcing rib yarn 111 in example 1, and the nylon fiber had a tensile breaking strength of 6.5cN/dtex and a linear density of 24tex, and other technical characteristics were as in example 1.

Comparative example 1

In this comparative example, the conventional single silica roving 110 was used without the reinforcing bar yarn 111 in example 1.

Comparative example 2

In this comparative example, on the basis of comparative example 1, the applicant tried to add nylon scrim on top of the silica cloth layer 102, the nylon scrim being separate from the middle silica cloth layer 102. Although the tensile strength and tear strength were better than those of example 1, the grammage of the product was outside the required range.

The following compares the performance of the silica cloth layers of inventive example 1 and comparative example 1:

comparison of raw material properties before and after reinforcement:

since the linear density of the reinforcing yarns is greater than that of the high purity silica roving, taking 24tex of reinforcing yarns per 6mm as an example, the increase in the fabric density is equivalent to 1.67 pieces/cm, it is necessary to reduce the warp and weft yarn linear density of the fabric to maintain the weight per unit area of the fabric, and the weight per unit area of the fabric can be designed.

The following compares the properties of the products of inventive examples 1, 2 and comparative examples 1, 2 before and after stiffening:

the original product was added with inorganic fillers such as mica, vermiculite, ceramic fibers, titanium dioxide, fumed silica and silica ultrafine fibers etc. in the adhesive, and the tearing strength of the product was <10N due to rigidity. The tear strength before reinforcement in the table is the strength after removal or reduction of the rigid inorganic filler, and the strength after reinforcement can be improved by at least 1/3.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art. The generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A flame retardant, fire retardant laminate film having improved tear strength, the structure of the flame retardant, fire retardant laminate film comprising:

a first layer comprising a first film (106);

a second layer comprising a silica cloth (102);

a third layer comprising a second film (108); and

an adhesive (104) comprising an inorganic filler, wherein: the adhesive (104) is positioned between the first layer and the second layer and between the second layer and the third layer, and the surface of the first layer or the third layer, and the silica cloth (102) is subjected to dip-dyeing treatment of the adhesive (104); it is characterized in that the method comprises the steps of,

the silica cloth (102) is made of high-purity silica roving (110) woven according to the original structure of the woven fabric, the density of warp yarns and weft yarns is 15-30 pieces/cm, and the warp yarns and weft yarns are separated by 4-10mm in the radial direction and the weft direction, and reinforcing rib yarns (111) are adopted to replace the high-purity silica roving (110).

2. The flame retardant and fire resistant laminate film with improved tear strength according to claim 1, wherein the reinforcing rib yarn (111) is one or more of nylon, terylene, aramid, carbon fiber, high-strength polyethylene fiber, polyphenylene sulfide fiber, polyimide fiber, high-strength glass fiber, and high-purity silica roving (110) with a linear density of more than 2 times.

3. A fire-retardant, fire-retardant laminated film with improved tear strength according to claim 1, characterized in that the material of the first film (106) is selected from one or more of a series of materials comprising: a fluoropolymer; a silicon polymer; polyether sulfone; polyether ether ketone; polyaryletherketone; polysulfone; a polyetherimide; polyetherketoneketone; polyphenylene sulfide; polyarylsulfone; and (3) an aluminum film.

4. A fire-retardant, fire-retardant laminated film with improved tear strength according to claim 1, characterized in that the material of the second film (108) is selected from one or more of a series of materials comprising: a fluoropolymer; a silicon polymer; polyether sulfone; polyether ether ketone; polyaryletherketone; polysulfone; a polyetherimide; polyetherketoneketone; polyphenylene sulfide; polyarylsulfone; and (3) an aluminum film.

5. A flame retardant and fire retardant laminated film with improved tear strength as claimed in claim 1, wherein the silica roving is bundled into a plurality of strands, each strand having a mass density of between 10 and 25 tex.

6. A fire retardant laminated film having improved tear strength according to claim 1, wherein the inorganic filler is selected from one or more of antimony trioxide, mica, vermiculite, ceramic fibers, titanium dioxide, fumed silica and silica ultrafine fibers; the mesh size of the inorganic filler is between 100 and 600 mesh.

7. A flame retardant, fire retardant laminated film having improved tear strength as claimed in claim 1 wherein the silica cloth (102) has an areal weight of 45-260 grams per square meter.

8. A flame retardant and fire retardant laminated film with improved tear strength according to claim 1, characterized in that the first layer film (106) and the second layer film (108) have a thickness between 3-9 μm.

9. A fire retardant laminated film having improved tear strength as claimed in claim 1 wherein the adhesive (104) layer has an areal weight of between 5 and 20 grams per square meter.

10. A fire retardant laminate film having improved tear strength as recited in claim 1, wherein the fire retardant laminate film has an areal weight of from 67 to 339 grams per square meter.

Images