JP2002004164A - Flame retardant resin-bonded nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame retardant resin-bonded nonwoven fabric exhibiting flame retardancy meeting the UL94 standard, hardly generating a toxious gas because of halogen free, and useful as functional parts for such as dustproof, binding, shading, cushioning in various kinds of instruments or machines. SOLUTION: This nonwoven fabric is obtained by impregnating 20-150 pts.wt. emulsion resin obtained by mixing 40-70 pts.wt. acrylic resin with 60-30 pts.wt. phosphorus-based flame retardant with 100 pts.wt. web obtained by carrying out mixed spinning of a flame retardant rayon fiber having the phosphorus-based flame retardant compounded therewith, with a flame-proofed fiber obtained by partially carbonizing a normal rayon fiber and/or a polyacrylonitrile fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-bonded nonwoven fabric obtained by impregnating a fiber web with a resin, and has a high degree of flame retardancy particularly used as a part for electric appliances and automobiles. The present invention relates to a resin-bonded nonwoven fabric.

[0002]

2. Description of the Related Art Conventionally, resin-bonded nonwoven fabrics have been widely used for purposes such as dustproofing, blindfolding, shading, and various types of buffering. Particularly, in the fields of acoustics, home appliances, automobiles, OA equipment, mobile phones, and the like. Widely used as parts. Of these, resin-bonded nonwoven fabrics used as parts for electric appliances and automobiles often require a high degree of flame retardancy depending on the place where they are used.

As a standard relating to the flame retardancy of a material, there is a UL (Underwriter's Laboratory) standard in the United States. U
The standard of L94 is a standard relating to the flame retardancy of a plastic material. However, regarding a resin-bonded nonwoven fabric, the standard is regarded as having validity, and the flame retardancy is certified in accordance with the standard.

[0004] V-0, V-1, and V-2 of UL94 are such that when a strip-shaped test piece hangs vertically and the lower end is ignited by a burner, the flame disappears quickly when the flame is kept away. , Test that the burning does not continue and that the ignited melt does not drop. V-0 requires the highest degree of flame retardancy.

Also, UL94 HF-1, HF-2, HB
F is a standard relating to the flame retardancy of a plastic foam in particular. When a strip-shaped test piece is placed horizontally on a wire mesh and one end of the test piece is ignited by a burner, the above-mentioned V standard is exceeded. Although it is moderate, almost the same flame retardancy is required, and HF-1 requires the most severe flame retardancy.

[0006] In the case of automobiles, various home electric appliances, audio equipment, and the like, the flame retardancy required for parts used in the design thereof is specified in accordance with the UL94 standard. I have.

In general, resin-bonded nonwoven fabrics using ordinary polyester fibers, nylon fibers, acrylic fibers, etc. as the web shrink when exposed to flame, and cannot conform to the UL94 standard. .

Therefore, conventionally, a web mainly composed of polyvinyl chloride fiber or polyvinylidene chloride fiber is impregnated with a resin solution in which a phosphorus-based flame retardant is blended with an acrylic resin emulsion, and has a self-extinguishing property that passes UL94V-0. A resin-bonded nonwoven fabric having flame retardancy has been used.

[0009] In order to pass the UL94HF-1, polyacryl (copolymer of polyvinyl alcohol and polyvinyl chloride) fibers or a web mainly composed of polyvinylidene chloride is impregnated with an acrylic resin. Resin-bonded nonwoven fabrics having extinguishing flame retardancy are used.

[0010]

However, since vinyl chloride and vinylidene chloride compositions contain chlorine, which is a halogen, there is a possibility that corrosive gases such as hydrogen chloride and toxic gases such as dioxin may be generated during combustion. .

For this reason, when vinyl chloride or vinylidene chloride is used for the web as described above, a product in which the resin-bonded nonwoven fabric is incorporated as a component is difficult to incinerate when it becomes waste. Therefore, it is becoming difficult to treat it as industrial waste.

The present invention has been made in view of the above circumstances, and a resin bond which does not generate harmful gas during incineration and has flame retardancy conforming to UL94 standard V-0 or HF-1. It is intended to provide a nonwoven fabric.

[0013]

Means for Solving the Problems The first invention of the present application is to partially carbonize flame-retardant rayon fibers, ordinary rayon fibers and / or polyacrylonitrile fibers into which a phosphorus-based flame retardant has been kneaded. To a web blended with
40 to 70 parts by weight of acrylic resin and 60 to 30 phosphorus-based flame retardant
Parts by weight of the emulsion resin mixed with
20 to 150 parts by weight with respect to 00.

In the present invention, the web includes:
A blend of 70 to 100 parts by weight of flame-retardant rayon fibers and 30 to 0 parts by weight of rayon fibers is suitable. Further, as another web configuration, flame-retardant rayon fibers 0 to 10 are used.
It is also preferable to use one comprising 0 parts by weight and 100 to 0 parts by weight of the flame-resistant fiber.

The flame-retardant rayon fiber used as the web in the present invention is a rayon fiber obtained by adding a phosphorus-based flame retardant to a stock solution, kneading the mixture, and spinning the stock solution.

The phosphorus-based flame retardant used here is a substance containing a phosphorus atom in the molecule, and a substance generally used as a phosphorus-based flame retardant can be used as it is. For example, phosphorus alone such as red phosphorus, phosphates such as calcium phosphate, titanium phosphate, ammonium phosphate, salts of phosphoric acid and amines, phosphates such as tributyl phosphate, triphenyl phosphate, and polyphosphoric acid , Polyphosphates, polyphosphates, amides of phosphoric acid or polyphosphoric acid with various amines, phosphine oxides such as triphenylphosphine oxide, phospholanes such as phenylphosphorane, diphenyl Phosphonic acids, such as phosphonic acid, and phosphine sulfides. Also, the amount used is suitably about 15% by weight based on the rayon stock solution.

In the process of carbonizing polyacrylonitrile fiber to produce carbon fiber, the flame-retardant fiber of the present invention is obtained by converting the polyacrylonitrile fiber into air in air for 200 hours.
A fiber obtained by infusibilizing by heating to ~ 300 ° C and partially carbonizing, the degree of carbonization of which is 60%
It is about.

This flame-resistant fiber is commercially available under the trade name of "Pyromex" manufactured by Toho Rayon Co., Ltd. or "Lastane" manufactured by Asahi Kasei Kogyo Co., Ltd. It does not adhere or melt when hit, and has a minimum oxygen index (LOI value) of 5
It has high flame retardancy of 5 to 60.

In the first invention, the flame-retardant rayon fiber and the flame-retardant fiber can be used alone, or can be used by blending at an arbitrary ratio. It is preferable to use it by blending with flame-retardant rayon fiber or flame-resistant fiber, and the usual amount of rayon fiber used is suitably 30% or less of the whole web. When the normal rayon fiber exceeds 30%, the flame retardant rayon fiber and the flame-resistant fiber are relatively reduced, and do not show sufficient flame retardancy.

In the present invention, as the phosphorus-based flame retardant used for the emulsion resin, the same one used for the flame-retardant rayon fiber and generally used as the phosphorus-based flame retardant can be used. .

It is particularly preferable to use a phosphorus / nitrogen flame retardant containing both phosphorus and nitrogen in the molecule. Examples of the phosphorus / nitrogen flame retardant include aliphatic amines such as ethylamine, butylamine, diethylamine, ethylenediamine, butylenediamine, triethylenetetramine, 1,2-diaminocyclohexane, and 1,2-diaminocyclooctane, aniline, and phenylene. Phosphazene compounds such as aromatic amines such as diamines, or phosphates or polyphosphates such as ammonia, propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene and aminophosphazene; N, N-diethylphosphamido Amides, such as poly (N,
Polyphosphoramides such as N-diethylphosphamide);
Examples include carbamyl phosphates and carbamyl polyphosphates.

The emulsion resin of the present invention comprises 40 to 70 parts by weight of an acrylic resin and 60 to 3 of the above-mentioned phosphorus-based flame retardant.
And 0 parts by weight. If the amount of the flame retardant is small, sufficient flame retardancy cannot be exhibited, and if the amount of the flame retardant is too large, the emulsion becomes unstable, the adhesive strength is reduced, and the texture of the nonwoven fabric is deteriorated. Occurs.

The flame-retardant resin-bonded nonwoven fabric of the present invention is obtained by impregnating the web with an emulsion resin. That is, the web is immersed in the emulsion resin,
20 to 150 parts by weight of the emulsion resin is added to 0 parts by weight, and after drying, heat treatment is performed at 140 ° C. for 3 to 5 minutes.

When the amount of the emulsion resin impregnated in the web is less than 20 parts by weight, the hand of the nonwoven fabric becomes excessively soft, and when it exceeds 150 parts by weight, the hand becomes excessively hard, and neither is preferable.

Further, the second invention of the present application is directed to a web in which 20 to 80 parts by weight of a flame retardant rayon fiber and 80 to 20 parts by weight of a rayon fiber are blended, and 20 to 150 parts by weight of an acrylic resin and a phosphorus-based flame retardant 40 20 to 150 parts by weight with respect to 100 weights of the web, with an emulsion resin obtained by mixing 5 to 5 parts by weight.

If the flame retardant rayon is less than 20 parts by weight of the web, sufficient flame retardancy cannot be secured, and if the flame retardant rayon exceeds 80 parts by weight, the flame retardancy is improved. This is undesirably unnecessarily high in cost.

If the amount of the flame retardant added to the emulsion resin is less than 5 parts by weight, the flame retardancy of the nonwoven fabric is insufficient. If it exceeds 40 parts by weight, the flame retardancy is improved, but the cost is unnecessarily high. Is not preferred.

[0028]

EXAMPLES [Experiment 1] (Example 1) A flame-retardant rayon fiber (LenzingViscose FR, manufactured by LENZING, trade name: 3D, fineness: 3D, cut length: 50 mm) kneaded with a phosphorus-based flame retardant, 80 g in weight. the / m ² in the web, an acrylic resin (Dainippon Ink and Chemicals Ltd., trade name "Boncoat R3360") to 65 parts by weight, a phosphorus-nitrogen flame retardant (Maruhishiyu of steel, Non'nen R996-1 (polyphosphoric acid carbamate )) Impregnated with 35 parts by weight of an emulsion resin at a solid content of 50 g / m ² and dried,
Heat treatment was performed at 40 ° C. for 5 minutes to obtain a resin-bonded nonwoven fabric having a basis weight of 130 g / m ² .

Comparative Example 1 In the same web as in Example 1, 75 parts by weight of an acrylic resin (same as in Example 1) and 25 parts by weight of a phosphorus / nitrogen-based flame retardant (same as in Example 1) were mixed. The emulsion resin was impregnated at a solid content of 50 g / m ² , dried and heat-treated in the same manner as in Example 1 to obtain a basis weight of 130 g / m ^2.
m ² resin-bonded nonwoven fabric was obtained.

Example 2 The same flame-retardant rayon fiber as shown in Example 1 and 70 parts by weight of ordinary rayon fiber (3D fineness, cut length of 50 to 76 mm) and a weight of 80 g / m ² were used. The web is impregnated with an emulsion resin obtained by mixing 60 parts by weight of an acrylic resin (same as in Example 1) with 40 parts by weight of a phosphorus / nitrogen-based flame retardant (same as in Example 1) at a solid content of 50 g / m ^2. Then, drying and heat treatment were performed in the same manner as in Example 1 to obtain a resin-bonded nonwoven fabric having a basis weight of 130 g / m ² .

(Comparative Example 2) An 80 g / m ² web consisting of 65 parts by weight of flame-retardant rayon fibers and 35 parts by weight of ordinary rayon fibers as in Example 1 was coated with the same emulsion as in Example 2. The resin was impregnated with a solid content of 50 g / m ² , dried and heat-treated in the same manner as in Example 1 to obtain a nonwoven fabric having a basis weight of 130 g / m ² .

(Flame Retardancy Test) For each of the samples of Examples 1 and 2 and Comparative Examples 1 and 2, five test pieces of 127 mm × 12.7 mm were sampled, and each test piece was evaluated by the UL94 vertical method. The flammability was tested and the results are shown in Table 1. The judgment of the test result is as follows.

：: passed UL94V-0 △: self-extinguishing, but burned to near the upper end of the test piece and passed or failed ×: failed Overall judgment: ５ passed three or more of the five test pieces And

[0034]

[Table 1]

In the first and second embodiments of the present invention, UL9
4 Passing level in vertical flame retardancy test, Comparative Examples 1 and 2
In the above, in the UL94 vertical flame retardancy test, the test piece burned to the upper end of the test piece, resulting in a failure.

It should be noted that, if the proportion of the flame retardant in the emulsion resin is increased, the flame retardancy is improved, but there is a disadvantage that the physical property value of the nonwoven fabric is reduced.

[Experiment 2] (Example 3) 50 parts by weight of the same flame-retardant rayon fiber as shown in Example 1 and a flame-resistant fiber (Pyromex, trade name 2D, manufactured by Toho Rayon Co., Ltd .; 76m
m) A web having a basis weight of 80 g / m ² consisting of 50 parts by weight,
An emulsion resin obtained by mixing 65 parts by weight of an acrylic resin (same as in Example 1) and 35 parts by weight of a phosphorus / nitrogen-based flame retardant (same as in Example 1) is impregnated at a solid content of 50 g / m ² ,
Drying and heat treatment were performed in the same manner as described in Example 1 to obtain a basis weight 13
A resin-bonded nonwoven fabric of 0 g / m ² was obtained.

Example 4 Using an 80 g / m ² web of the same oxidized fiber as shown in Example 3,
The resin was impregnated with the emulsion resin in the same manner as described above, dried and heat-treated to obtain a resin-bonded nonwoven fabric of 130 g / m ² .

(Flame Retardancy Test) The samples of Example 1 and Examples 3 and 4 were subjected to UL9
4 A flame retardancy test based on the vertical method was performed, and the results are shown in Table 2. The evaluation of the test results is as described in Experiment 1.

[0040]

[Table 2]

As shown in Table 2, in Examples 1, 3 and 4 of the present invention, all of them were of a level that could pass V-0 in the UL94 vertical flame retardancy test, In all mixing ranges of the flame retardant rayon fiber into which the flame retardant is kneaded and the flame-resistant fiber, UL94 is used.
It has flame retardancy that can pass V-0.

In order to pass UL94V-0, it is necessary that the nonwoven fabric does not shrink by burning and has a self-extinguishing property, but the above Examples 1, 2, 3 and 4 satisfy these conditions. I have. In Comparative Examples 1 and 2, since the self-extinguishing property was insufficient, it burned to the upper end of the test piece which was drooped.

[Experiment 3] (Example 5) A basis made of 50 parts by weight of the same flame-retardant rayon fiber as shown in Example 1 and 50 parts by weight of ordinary rayon fiber (same as Example 2), having a basis weight of 80 g / in m ² of the web,
Emulsion resin obtained by mixing 80 parts by weight of an acrylic resin (same as in Example 1) with 20 parts by weight of a phosphorus / nitrogen-based flame retardant (manufactured by Marubishi Yuka, polycarbamate + guanidine phosphate, trade name: Nonen NF-2) Was impregnated at a solid content of 50 g / m ² and dried and heat-treated in the same manner as described in Example 1.
A resin-bonded nonwoven fabric having a basis weight of 130 g / m ² was obtained.

Comparative Example 3 An acrylic resin (same as in Example 1) emulsion resin was applied to a web having a basis weight of 80 g / m ² consisting of only the same flame-retardant rayon fibers as shown in Example 1 and a solid content of 50 g. / m ² and dried and heat-treated in the same manner as described in Example 1 to obtain a resin-bonded nonwoven fabric having a basis weight of 130 g / m ² .

For each of the samples of Example 5 and Comparative Example 3, five test specimens each measuring 152 mm × 50.8 mm were collected, and each specimen was tested for flame retardancy by the UL94 horizontal method. It is shown in Table 3. Evaluation of the test results is as follows.

：: passed UL94HF-1 (combustion influence distance is 58 mm
×): unacceptable (combustion influence distance exceeds 58 mm) Overall judgment: 3 or more of 5 test specimens are accepted.

[0047]

[Table 3]

[0048]

As described above, according to the present invention, the resin-bonded non-woven fabric exhibits flame retardancy conforming to the UL94 standard and contains no halogen, so that no harmful gas is generated even when incinerated. It is extremely useful as a component having functions such as dust prevention, blindfolding, light shielding, and various types of buffering in various devices.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // D06M 101: 08 D06M 101: 08 101: 28 101: 28

Claims (4)

[Claims] An acrylic resin 40 is added to a web obtained by blending flame-retardant rayon fibers into which a phosphorus-based flame retardant is kneaded, ordinary rayon fibers and / or flame-resistant fibers obtained by partially carbonizing polyacrylonitrile fibers. A flame-retardant resin-bonded nonwoven fabric, characterized by impregnating an emulsion resin obtained by mixing 20 to 150 parts by weight with respect to a web weight of 100 to 70 to 70 parts by weight and a phosphorus-based flame retardant of 60 to 30 parts by weight. 2. The method according to claim 1, wherein the web is made of flame-retardant rayon fibers.
The flame-retardant resin-bonded nonwoven fabric according to claim 1, characterized in that the resin-blended non-woven fabric according to claim 1, wherein the resin-blended non-woven fabric is a blend of 100 to 100 parts by weight and 30 to 0 parts by weight of rayon fiber. 3. The method according to claim 1, wherein the web is a non-flammable rayon fiber.
The flame-retardant resin-bonded nonwoven fabric according to claim 1, comprising 100 parts by weight and 100 to 0 parts by weight of the oxidized fiber. 4. A web obtained by blending 20 to 80 parts by weight of a flame retardant rayon fiber into which a phosphorus-based flame retardant is kneaded and 80 to 20 parts by weight of a rayon fiber, and adding 20 to 150 parts by weight of an acrylic resin to the web. A flame-retardant resin-bonded nonwoven fabric characterized by being impregnated with 20 to 150 parts by weight of an emulsion resin obtained by mixing 40 to 5 parts by weight of a flame retardant with respect to a web weight of 100.