JPS6357540B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a novel flame-retardant nonwoven fabric. More specifically, the present invention relates to a nonwoven fabric that contains a specific flame-retardant suspension in the intermediate layer, has little release of the suspension, and has flexibility as a whole. [Prior Art] When the fiber material constituting the nonwoven fabric is nonflammable or flame retardant, such as an inorganic substance, wholly aromatic polyamide, polyvinyl chloride, or polyvinylidene chloride,
Although it can easily achieve the purpose of flame retardancy by itself,
Nonwoven fabrics made from synthetic fibers made from many other natural fibers, recycled fibers, polyamides other than fully aromatic polyamides, polyesters, polyolefins, and other synthetic polymers are not subjected to any flame retardant treatment. No flame retardant property is provided. For this reason, various methods have been proposed for making nonwoven fabric flame retardant. For example, there are a method of copolymerizing a flame retardant component, a method of kneading the component, a method of adhering the component, and the like. Of these, the method of attaching a flame retardant component is considered to be the simplest method to impart flame retardancy, but if the flame retardant is solid, it easily falls off, so it may not have an excellent flame retardant effect. However, its durability is poor and it cannot be applied to adhesion methods in many cases. On the other hand, if the flame retardant is a liquid, it is highly likely to migrate to other objects and cause contamination. In order to reduce these shedding, migration, and contamination, many methods are used to fix flame retardants to cloth or the like using a thermosetting binder. However, this method requires complicated steps, and the texture of the nonwoven fabric to be made flame retardant is impaired, resulting in poor flexibility. [Object of the invention] Therefore, the object of the present invention is to prevent the shedding, migration, and
An object of the present invention is to provide a flame-retardant nonwoven fabric that causes less contamination and less decrease in flexibility. [Structure of the Invention] The flame-retardant nonwoven fabric of the present invention has a viscosity of 0.02 to 100 poise, and contains 20 to 90% by weight of a nonvolatile liquid organic compound that does not substantially contain water, and a substantially A flame-retardant suspension formed by 80 to 10% by weight of a particulate solid flame-retardant substance that is insoluble in water and has an average particle size of less than 50 mesh is added to the entire non-woven fabric made of flame-retardant fibers. This is a flame-retardant nonwoven fabric in which an intermediate layer containing 5 to 100% by weight is interposed between upper and lower layers that do not contain a flame-retardant suspension, and all layers are integrated. In the particulate solid flame retardant material according to the present invention, "substantially insoluble" means that the solubility in the nonvolatile liquid-paired organic compound is 5% by weight or less. Furthermore, the term "non-volatile liquid organic compound" means an organic liquid having a vapor pressure of 1 mmHg or less at a temperature of 25°C. The average particle size of the particulate solid flame retardant material in the present invention is measured as follows. The solid is sampled on a slide, the particle size is measured, and the average is averaged. The average particle size (m) is calculated using the following formula, assuming that the average value is the sum of the values. (However, it shall be expressed in units of cm.) In that case, if the projection of the solid particle is not circular, the projected area (S) is measured for each sampled particle, and the radius (γ) of each particle is calculated as γ = √. It is assumed that the value is obtained by calculating the value using the formula and performing an arithmetic average of these γ's. The viscosity of the nonvolatile organic liquid used in the present invention was determined using a rotating cylinder viscometer, and was measured at a shear rate of 1/sec and a temperature of 25°C. If the viscosity is time-dependent, it refers to the viscosity after rotating the cylinder (rotor) for 30 minutes. The reason why a non-volatile organic liquid is used here is that if it is volatile, it will vaporize after being applied to the nonwoven fabric and the holding power of the solid flame retardant substance will be lost, making it impossible to achieve the purpose of the present invention. The flame retardant suspension in the present invention is formed from the nonvolatile organic liquid and the solid flame retardant substance, and it is sufficient that the solid flame retardant substance is at least flame retardant; The organic liquid may also have a flame retardant function, and there is no problem even if the two are combined to have a flame retardant function. These liquids and solids may be used alone or in a mixture of two or more. When the flame retardant suspension used in the present invention is included in a nonwoven fabric in a specific proportion, the flame retardant nonwoven fabric has extremely low liquid migration and solid shedding, and does not lose its original flexibility. can be obtained. Non-volatile liquid organic compounds have a viscosity of
0.02 to 100 poise, preferably 0.5 to 20 poise. If the viscosity is less than 0.02 poise,
The solid-liquid separation in the flame retardant suspension is severe, making it difficult to obtain a stable suspension, which not only makes it difficult to homogeneously apply the suspension to the nonwoven fabric, but also makes it more likely to fall off or migrate. . Furthermore, if a liquid with a strength exceeding 100 poise is used, it will be difficult to apply a flame retardant suspension using the liquid to the nonwoven fabric, and even if it is applied, it will lack uniformity and the nonwoven fabric will lose its flexibility. Specific examples of suitable liquid organic compounds include, for example, ethylene glycol, polyethylene glycol, liquid paraffin, polysiloxane, chlorinated paraffin, bromotrichloromethane, tetrabromoethane, 1,2-dibromo-1,1,2,2 −
Tetrachloroethane, tribromopropane, 1,
2-dibromo-3-chloropropane, tetrabromobutane, tris(2,3-dibromopropyl)
Phosphate, Tris(2-chloro-3-promopropyl)phosphate, Tris(2-bromo-
3-chloropropyl) phosphate and the like. Among these, the substances fried after chlorinated paraffin have flame retardant properties by themselves. On the other hand, solid flame retardant materials are those in the form of fine powders whose average particle size is less than 50 mesh. If the size is larger than 50 meshes, it is difficult to uniformly disperse it on the nonwoven fabric, and the co-retention ability with liquid is also reduced. Only particles with an average particle size smaller than 50 mesh can be uniformly dispersed and also have good co-retention with liquid organic compounds. Examples of such flame-retardant solids include inorganic compounds mainly containing oxides such as copper oxide, zinc oxide, tin oxide, silica, antimony trioxide, iron oxide, nickel oxide, and aluminum hydroxide; elements such as activated carbon, graphite), lead, iron; tetrabromo bisphenol A, carbonate oligomer of tetrabromo bisphenol A, tetrabromo bisphenol A derivatives; hexabromo benzene, decabromodiphenyl ether, tetrabromo phthalic anhydride, Examples include organic halogenated compounds having a flame retardant effect such as perchloropentacyclodecane. The flame retardant suspension of the present invention is formed from the liquid and solid, and its composition is such that the liquid is 20 to 90% by weight.
and the solids content is 80-10% by weight. The preferred composition is 30-80% liquid by weight and 70-80% solids.
20% by weight. It is more advantageous that the viscosity of the suspension is in the range of 0.1 to 200 poise, preferably 1 to 20 poise. If the amount of liquid in the flame retardant suspension exceeds 90% by weight, the retention of solids will be reduced and the liquid will migrate or fall off more easily, not only making it easier to contaminate other properties.
The flame retardancy of the nonwoven fabric also tends to decrease. On the other hand, if the proportion of the liquid is less than 20% by weight, the adhesion effect of the liquid to the solid will be reduced, and the migration and falling off of the solid will become noticeable, making it easier to contaminate other objects. may also decrease. The flame retardant suspension described above may contain small proportions of additives such as pigments and various stabilizers in addition to the liquids and solids described above. The flame retardant suspension is applied to the nonwoven fabric to be flame retardant (adhered nonwoven fabric) by 5 to 100% by weight, preferably
15-70% granted. If it is less than 5%, the nonwoven fabric will not be sufficiently flame retardant, and if it exceeds 100%, the original properties of the nonwoven fabric will be lost, and migration and shedding of the flame retardant suspension will become noticeable. . The flame retardant effect obtained by applying the flame retardant suspension of the present invention is most sustained when the flame retardant suspension is applied to the middle layer of a nonwoven fabric having a multilayer structure. The flame retardant suspension is easily applied to and incorporated into the web, which becomes the intermediate layer of the nonwoven fabric, by means such as rotating rolls, spraying, and bath dipping. Examples of effective methods for producing a flame-retardant nonwoven fabric with a multilayer structure include the following processes (a) to (c). (a) A flame retardant suspension specified in the present invention is applied to the web that will become the intermediate layer. (b) Upper and lower layers not coated with a flame retardant suspension are laminated on the intermediate layer. (c) The upper, middle, and lower layers are joined together by a process such as stretching and pressing or needle punching and pressing to form a nonwoven fabric. [Effects of the invention] The flame-retardant nonwoven fabric with a multilayer structure thus produced has excellent long-lasting flame retardancy, and the flexibility of the original fabric remains, so it can be used as a textured board material. It is suitably used in fields where flame retardancy is required, such as decorative surface materials for thermoformed products and materials that require easy deformation. [Examples] The present invention will be specifically described below with reference to Examples. In addition, "parts" in the examples are parts by weight unless otherwise specified, and "%" are percentages by weight unless otherwise specified.
It is. Example 1 A 40% chlorinated chlorinated paraffin with a viscosity of 1500 centipoise (“Toyoparax” manufactured by Toyo Soda)
A40) 80 parts, average particle size 300 mesh decabromodiphenyl ether (Mitsui Toatsu "Planeron")
40 parts, powder graphite (Nippon Graphite "P#2")
Mix 8 parts and homogenize with a normal propeller stirrer,
A stable black flame retardant suspension (F) with a viscosity of 2000 centipoise was obtained. On the other hand, the intrinsic viscosity of orthochlorophenol is
70 parts of polyethylene terephthalate, which is 0.70;
Polypropylene (“S-115M” manufactured by Ube Industries) 27
1 part, 3 parts of black polypropylene master chips ("PPM (F) 8 Black" manufactured by Dainichiseika Chemical Co., Ltd.) and 1 part of talc were dry blended, and the dry blend chips were melted as in the invention of Japanese Patent Publication No. 47-36833. do,
A nonwoven web (W) with numerous cracks in the winding direction was obtained by blowing nitrogen into it, extruding it, and winding it up under a draft. Eight layers of this nonwoven web (W) were stacked, spread while overfeeding, and pressed. The above flame retardant suspension (F) is applied in advance to the fourth layer nonwoven web at 400% of the weight of the fourth layer nonwoven web, and through the steps of lamination → overfeed → spreading → pressing, A nonwoven fabric (W-F) with a basis weight of 60 g/m ² and an overall adhesion amount of (F) of 60% was obtained. This nonwoven fabric (W-F) itself exhibited excellent water repellency and flame retardancy, and there was little migration or shedding of the flame retardant suspension (F) in the nonwoven fabric. Next, the above nonwoven fabric (W-F) and felt (commonly known as Taka (T)), which is mainly made of cotton with a basis weight of 600 g/m ² and contains 20% uncured phenol resin, are integrally thermoformed to a thickness of 4 mm ( S), the above nonwoven fabric (W-
When the JIS D1201 combustion test was conducted with the F) side facing down, the results were found to be "self-extinguishing." Also, if you rub the above nonwoven fabric (W-F) on drawing paper 10 times and then paste it on Taka (T) in the same way,
The result of JIS D1201 was "self-extinguishing". There was also almost no transfer of flame retardant to the drawing paper. Furthermore, there was no migration of graphite, and this nonwoven fabric had excellent color fastness. Comparative Examples 1 to 7 Nonwoven fabrics made in the same manner as in Example 1 except for the matters listed in Table 1 were used as Taka (T) and Example 1.
Flame retardant (JIS D1201) of the non-woven fabric integrally heat-molded under the same conditions as the non-woven fabric (JIS D1201), and flame retardant of the non-woven fabric integrally heat-molded with Taka (T) after rubbing it on drawing paper about 10 times (JIS D1201) (flame retardant) The evaluation results for the nonwoven fabric (W-F) of Example 1 are listed in Table 2 together with the evaluation results for the nonwoven fabric (W-F) of Example 1 regarding the degree of shedding of solids when rubbed against drawing paper, the degree of liquid migration, and the flexibility of the outer nonwoven fabric. These nonwoven fabrics that deviate from the scope of the present invention are inferior to the nonwoven fabric of Example 1 (W-F) in any of the following items.

【table】

[Table] Examples 2 to 4 Nonwoven fabrics made in the same manner as in Example 1 except for the matters listed in Table 3 were evaluated in the same manner as in Comparative Examples 1 to 6. The results were almost the same as the nonwoven fabric of Example 1. Ta.

【table】

[Table] Example 5 40 parts of liquid paraffin (manufactured by Kanto Kagaku) with a viscosity of 150 centipoise, 57 parts of decabromodiphenyl ether ("Planelon", manufactured by Mitsui Toatsu) with an average particle size of 300 mesh, powdered graphite ("Planelon", manufactured by Nippon Graphite), P
#2'') were mixed and homogenized using a conventional propeller-type stirrer to obtain a gray flame-retardant suspension (F) having a viscosity of 1100 centipoise. About 25 g/m ² of this flame-retardant suspension (F) was attached to a parallel nonwoven fabric (H) with a basis weight of 30 g/m ² obtained by opening stretched polyethylene terephthalate tow, and the two layers of the nonwoven fabric were used as examples. Fabric weight 20 with countless cracks in the winding direction manufactured by the same method with the same ingredients as 1.
It was inserted between five layers of non-woven fabric (W) with a weight of 31 g/m ² and one layer of cracked non-woven fabric made of 100% polypropylene produced as in Japanese Patent Publication No. 47-36833 with a basis weight of 31 g/m ² was superimposed on one side. Ta. The laminate was stretched and pressed while overfeeding to obtain a flame-retardant nonwoven fabric (WF) having a basis weight of 65 g/m ² and a thickness of 125 μm. The nonwoven fabric (W-F) itself exhibited excellent water repellency and exhibited "self-extinguishing properties" in the JIS D1201 test. Next, the nonwoven fabric (W-F) and a glass fiber mat (G) containing 20% uncured phenolic resin with a basis weight of 700 g/m ² were placed with the 100% polypropylene side of (W-F) facing the glass fiber mat. 25 by integrally heat molding the
A molded article (S) with a thickness of mm was obtained. The nonwoven fabric (W-F)
The JIS D1201 test was conducted with the material facing down, and the result was that it was "self-extinguishing." Example 6 50 parts of tris(2,3-dichloropropyl) phosphate having a viscosity of 2 poise and 50 parts of talc having an average particle size of 500 mesh were mixed to obtain a flame retardant suspension (F) having a viscosity of 50 poise. The suspension (F) was applied at 15 g/m ² to a polyester short fiber non-woven fabric (W) having a basis weight of 30 g/m ² and used as an intermediate layer, which was laminated and needle-punched with the upper and lower layers not containing the suspension. A flame-retardant nonwoven fabric (WF) without stickiness was obtained. This nonwoven fabric (W-F) itself exhibits semi-permanent flame retardancy, and can be used with other base materials such as Example 1 and Example 2.
The molded product, which was integrally thermoformed using 20μ thick polyethylene, also exhibited "self-extinguishing properties" according to JIS D1201. Example 7 80 parts of poly-ε-caprolactam with an intrinsic viscosity of 1.1 in metacresol, 10 parts of polypropylene (“TS-115M” manufactured by Ube Industries), and 10 parts of polyethylene terephthalate with an intrinsic viscosity of 0.55 in orthochlorophenol. and 2 parts of talc were dry blended to obtain a cracked sheet (W) as described in Japanese Patent Publication No. 47-36833. Using this sheet, the same flame retardant was applied in an amount of 50% based on the total weight of W in the same process as in Example 1 to obtain a flame retardant nonwoven fabric (WF) with a basis weight of 60 g/m ² . Next, the nonwoven fabric (W-F) and a felt containing 20% uncured phenolic resin, which is mainly cotton with a basis weight of 600 g/m ² , were thermoformed into a 4 mm thick molded product (S).
was "self-extinguishing" in the JIS D1201 test. Example 8 A nonwoven fabric (W-F) produced in exactly the same manner as in Example 1 except that tetrabromo phthalic anhydride (200 mesh) was used instead of decabromodiphenyl ether was excellent. It exhibited durable flame retardancy and retained flexibility.

Claims (1)

[Claims] 1 Nonvolatile liquid organic compound with a viscosity of 0.02 to 100 poise and substantially free of water 20 to 90
% by weight and 80 to 10% by weight of a particulate solid flame retardant material that is substantially insoluble in the liquid and has an average particle size smaller than 50 mesh. A flame-retardant material in which an intermediate layer containing 5 to 100% by weight of the entire nonwoven fabric made of fibers is interposed between upper and lower layers that do not contain a flame-retardant suspension, and all layers are bonded together. Non-woven fabric.