Flame retardant synthetic leather

Abstract

Flame retardant synthetic leather having high flame retardancy and excellent physical properties (light resistance, heat resistance and feeling). The flame retardant synthetic leather contains an organic phosphorus compound (component A) represented by the following formula (1). ##STR00001##
(In the formula, X.sup.1 and X.sup.2 are the same or different and each an aromatic substituted alkyl group represented by the following formula (2).)
AL(Ar).sub.n(2)
(In the formula, AL is a branched or linear aliphatic hydrocarbon group having 1 to 5 carbon atoms, and Ar is a phenyl group, naphthyl group or anthryl group, all of which may have a substituent. n is an integer of 1 to 3, and Ar may be bonded to any carbon atom contained in AL.)

Claims

1. A flame retardant synthetic leather comprising a fiber substrate, an adhesive layer and a surface resin layer, (i) wherein the surface resin layer comprises a polyurethane and has a thickness of 10 to 500 m, and (ii) wherein an organic phosphorus compound of the following formula (1-a), which has an average particle diameter of 5 to 100 m is contained in at least one selected from the group consisting of the fiber substrate, the adhesive layer and the surface resin layer, ##STR00007##

2. The flame retardant synthetic leather according to claim 1, wherein the organic phosphorus compound of the formula (1-a) is contained in an amount of 1 to 300 parts by weight based on 100 parts by weight of the fiber substrate.

3. The flame retardant synthetic leather according to claim 1, wherein the organic phosphorus compound of the formula (1-a) is contained in an amount of 1 to 300 parts by weight based on 100 parts by weight of the surface resin layer.

4. The flame retardant synthetic leather according to claim 1, wherein the organic phosphorus compound of the formula (1-a) is contained in an amount of 1 to 300 parts by weight based on 100 parts by weight of the adhesive layer.

5. The flame retardant synthetic leather according to claim 1, wherein at least one compound selected from the group consisting of aluminum hydroxide, titanium oxide, zinc oxide, expandable graphite, magnesium hydroxide, calcium carbonate, zinc borate, melamine, red phosphorus, ammonium polyphosphate, melamine polyphosphate, melamine cyanurate and phosphoric ester is contained in an amount of 1 to 200 parts by weight based on 100 parts by weight of the organic phosphorus compound of the formula (1-a).

Description

EXAMPLES

(1) The following examples are provided for the purpose of further illustrating the present invention but are in no way to be taken as limiting the technical scope of the invention. Parts and mean parts by weight and wt %, respectively, and evaluations were made by the following methods.

(2) (1) Frame Retardancy 1

(3) Flame retardancy was evaluated in accordance with FMVSS-302. For evaluation, the combustion distance from the gauge line, the time taken to burn this distance from the gauge line and the combustion rate from the gauge line were each measured three times as specified in FMVSS-302. Nonflammable means automatic extinction below the gauge line, h sample having a combustion rate higher than 10 cm/min is rejected.

(4) (2) Flame Retardancy 2

(5) The char length was measured by the 45 air mix burner wire net method of the Fire Service Act. A combustion test was carried out by immersing a combustion test specimen in hot water (502 C.30 minutes) and drying it. When the char length is not more than 7 cm at maximum and not more than 5 cm on average, flame retardancy is acceptable.

(6) (3) Light Resistance

(7) As for light resistance, the degree of discoloration after 200 hours of exposure to 83 C. was judged by using a fade meter (JIS-L0842, carbon are lighting method; grade determined by judging the degree of discoloration with a JIS discoloration blue scale; as the grade becomes higher, light resistance becomes higher).

(8) (4) Heat Resistance

(9) As for heat resistance, the degree of discoloration after 60 minutes of a treatment at 150 C. in a gear oven drier was checked. means that no discoloration is seen and means that discoloration is seen.

(10) (5) Feeling

(11) Feeling was judged by touch with the hand.

(12) (6) Acid Value

(13) This was measured in accordance with JIS-K-3504.

Preparation Example 1

Preparation of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-dibenzyl-3,9-dioxide (FR-1)

(14) 22.55 g (0.055 mole) of 3,9-dibenzyloxy-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5]undecane, 19.01 g (0.11 mole) of benzyl bromide and 33.54 g (0.32 mole) of xylene were charged into a reactor having a stirrer, a thermometer and a condenser, and dry nitrogen was let flow into the reactor under agitation at room, temperature. Then, heating was started with an oil bath to heat the above mixture at a reflux temperature (about 130 C. for 4 hours under agitation.

(15) After the end of heating, the resulting mixture was left to be cooled to room temperature, and 20 ml, of xylene was added and further stirred for another 30 minutes. The precipitated crystal was separated by filtration and washed with 20 mL of xylene twice. The obtained roughly purified product and 40 mL of methanol were injected into a reactor equipped with a condenser and a stirrer to be refluxed for about 2 hours. After the crystal was cooled to room temperature, it was separated by filtration and washed with 20 mL of methanol, and the obtained filtrate was dried at 120 C. and 1.3310.sup.2 Pa for 19 hours to obtain a white flaky crystal.

(16) It was confirmed by mass spectral analysis, .sup.1H and .sup.31P nuclear magnetic resonance spectral analysis and elemental analysis that the product was bisbenzyl pentaerythritol diphosphonate. The yield was 20.60 g, the yield rate was 91%, and the .sup.31PNMR purify was 99%.

(17) The HPLC purity measured by the method described in this text was 99%. The acid value was 0.05 mgKOH/g.

(18) .sup.1H-NMR (DMSO-d.sub.6, 300 MHz): 7.2-7.4 (m, 10H), 4.1-4.5 (m, 8H), 3.5 (d, 4H), .sup.31P-NMR (DMSO-d.sub.6, 120 MHz): 23.1 (S), melting point: 257 C., average particle diameter: 30 m

(19) 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane, 3,9-dibenzyl-3,9-dioxide {phosphorus-based compound of the formula (1-a) (to be referred to as FR-1 hereinafter)} synthesized in Preparation Example 1 was used as the organic phosphorus compound (component A) used in Examples.

Example 1

(20) A flame retardant was added to the surface resin layer in this example.

(21) <Treatment Liquid 1> (Processing Liquid for Surface Resin Layer)

(22) TABLE-US-00001 Polycarbonate-based polyurethane resin (solid content of 100 parts 30%, DMF solvent) MEK 50 parts Pigment (carbon black) 12 parts FR-1 (flame retardant) 20 parts Crosslinking agent 2 parts

(23) The processing liquid for the surface, resin layer prepared by the formulation of the treatment liquid 1 was applied to release paper with a doctor knife to a thickness of 0.1 mm (after drying) and heated at 100 C. for 2 minutes in a drier.

(24) <Treatment Liquid 2> (Processing Liquid for Adhesive Layer)

(25) TABLE-US-00002 Ester-based polyurethane resin (solid content of 50%, DMF 100 parts solvent) Urethane curing agent 10 parts Urethane curing catalyst 1 part Pigment (carbon black) 5 parts

(26) Subsequently, the processing liquid for the adhesive layer prepared by the formulation of the treatment liquid 2 was applied to the surface resin layer on the release paper with a doctor knife to a thickness of 0.1 mm (after drying), laminated on a polyester woven fabric (weight: 200 g/m.sup.2) and pressed by means of a mangle (4 kg/m.sup.2) and the obtained laminate was aged at 60 C. for 21 hours or more to obtain flame retardant synthetic leather.

Comparative Example 1

(27) Synthetic leather was obtained in the same manner as in Example 1 except that a flame retardant was not contained in the surface resin layer.

Comparative Example 2

(28) Synthetic leather was obtained in the same manner as in Example 1 except that 20 parts of decabromodiphenyl ether was used in place of FR-1 as a flame retardant for the surface resin layer.

Comparative Example 3

(29) Synthetic leather was obtained in the same manner as in Example 1 except that 20 parts of trisdichloropropyl phosphate was used in place of FR-1 as a flame retardant for the surface resin layer.

(30) (test results): Flame retardancy (evaluation of flame retardancy 1) is shown in Table 1, and physical properties are shown in Table 2.

(31) TABLE-US-00003 TABLE 1 Flame retardancy test (FMVSS-302) n = 1 n = 2 n = 3 Distance Time Rate Distance Time Rate Distance Time Rate Sample name (mm) (sec) (cm/min) (mm) (sec) (cm/min) (mm) (sec) (cm/min) Example 1 0 0 non- 0 0 non- 0 0 non- flammable flammable flammable Comparative 270 119 13.6 270 103 15.7 270 132 12.3 Example 1 Comparative 0 0 non- 0 0 non- 0 0 non- Example 2 flammable flammable flammable Comparative 142 168 5.1 162 198 4.9 172 173 6.0 Example 3

(32) TABLE-US-00004 TABLE 2 Sample name Light resistance Heat resistance Feeling Example 1 grades 4 to 5 Good Comparative Example 1 grades 4 to 5 Good Comparative Example 2 grade 4 Slightly hard Comparative Example 3 grades 3 to 4 Slightly tucked

Example 2

(33) A flame retardant was added to the surface resin layer and the adhesive layer in this example.

(34) <Treatment Liquid 3> (Processing Liquid for Surface Resin Layer)

(35) TABLE-US-00005 Polycarbonate-based polyurethane resin (solid content of 100 parts 30%, DMF solvent) MEK 50 parts Pigment (carbon black) 12 parts FR-1 (flame retardant) 30 parts Crosslinking agent 2 parts

(36) The processing liquid for the surface resin layer prepared by the formulation of the treatment liquid 3 was applied to release paper with a doctor knife to a thickness of 0.1 mm (after drying) and heated at 100 C. for 2 minutes in a drier.

(37) <Treatment Liquid 4> (Processing Liquid for Adhesive Layer)

(38) TABLE-US-00006 Ester-based polyurethane resin (solid content of 50%, DMF 100 parts solvent) Urethane curing agent 10 parts Urethane curing catalyst 1 part Pigment (carbon black) 5 parts FR-1 (flame retardant) 30 parts

(39) Subsequently, the processing liquid for the adhesive layer prepared by the formulation of the treatment liquid 4 was applied to the surface resin layer on the release paper with a doctor knife to a thickness of 0.1 mm (after drying), laminated on polyester jersey cloth (weight: 150 g/m.sup.2) and pressed by means of a mangle (4 kg/m.sup.2), and the obtained laminate was aged at 60 C. for 24 hours or more to obtain flame retardant synthetic leather.

Comparative Example 4

(40) Synthetic leather was obtained in the same manner as in Example 2 except that a flame retardant was not contained in the surface resin layer and the adhesive layer.

Comparative Example 5

(41) Synthetic leather was obtained in the same manner as in Example 2 except, that 30 parts of decabromodiphenyl ether was used in place of FR-1 as a flame retardant for the surface resin layer and the adhesive layer.

Comparative Example 6

(42) Synthetic leather was obtained in the same manner as in Example 2 except that 30 parts of ammonium polyphosphate was used in place of FR-1 as a flame retardant for the surface resin layer and the adhesive layer.

(43) (test results): Flame retardancy (evaluation of flame retardancy 2) is shown in Table 3, and physical properties are shown in Table 4.

(44) TABLE-US-00007 TABLE 3 45 air mix burner wire net method of the Fire Service Act Char length Sample name n = 1 n = 2 n = 3 Example 2 3.8 4.2 3.9 Comparative Example 4 Comparative 4.0 4.1 4.2 Example 5 Comparative Example 6

(45) TABLE-US-00008 TABLE 4 Light Heat resistance resistance Feeling Example 2 grades 4 to 5 Good Comparative grades 4 to 5 Good Example 4 Comparative grades 3 to 4 Good Example 5 Comparative grade 4 Slightly hard Example 6

Example 3

(46) A flame retardant was added to a fiber substrate, in this example.

(47) The fiber substrate was first flame retarded. Treatment liquid (flame-retarding processing liquid for fiber substrate): 50 parts of FR-1 (flame retardant) was added to a solution prepared by adding 10 parts of a surfactant (dispersant) and 40 parts of water to 100 parts of an ester-based polyurethane resin (solid content of 50%, water solvent) wider agitation.

(48) A polyester woven fabric (weight: 200 g/m.sup.2) was padded with the above processing liquid for the fiber substrate (squeeze rate of 80%), dried at 80 C. for 5 minutes and heated at 150 C. for 1 minute to obtain a flame retarded fiber substrate.

(49) <Treatment Liquid 5> (Processing Liquid for Surface Resin Layer)

(50) TABLE-US-00009 Polycarbonate-based polyurethane resin (solid content of 100 parts 30%, DMF solvent) MEK 50 parts Pigment (carbon black) 12 parts Crosslinking agent 2 parts

(51) The processing liquid for the surface resin layer prepared by the formulation of the treatment liquid 5 was applied to release paper with a doctor knife to a thickness of 0.1 mm (after drying) and heated at 100 C. for 2 minutes in a drier.

(52) <Treatment Liquid 6> (Processing Liquid for Adhesive Layer)

(53) TABLE-US-00010 Ester-based polyurethane resin (solid content of 50%, DMF 100 parts solvent Urethane curing agent 10 parts Urethane curing catalyst 1 part Pigment (carbon black) 5 parts

(54) Subsequently, the processing liquid for the adhesive layer prepared by the formulation of the treatment liquid 6 was applied to the surface resin layer on the release paper with a doctor knife to a thickness of 0.1 mm (after drying), laminated on the flame retarded fiber substrate and pressed by means of a mangle (4 kg/m.sup.2), and the obtained laminate was aged at 60 C. for 24 hours or more to obtain flame retardant synthetic leather.

Comparative Example 7

(55) Synthetic leather was obtained in the same manner as in Example 3 except that a flame retardant was not contained in the fiber substrate.

Comparative Example 8

(56) Synthetic leather was obtained in the same manner as in Example 3 except that 50 parts of decabromodiphenyl ether was used in place of FR-1 as a flame retardant for the fiber substrate.

Comparative Example 9

(57) Synthetic leather was obtained in the same manner as in Example 3 except that 50 parts of trisdichloropropyl phosphate was used in place of FR-1 as a flame retardant for the fiber substrate.

(58) (test results): Flame retardancy (evaluation of flame retardancy 1) is shown in Table 5, and physical properties are shown in Table 6.

(59) TABLE-US-00011 TABLE 5 Flame retardancy test (FMVSS-302) n = 1 n = 2 n = 3 Distance Time Rate Distance Time Rate Distance Time Rate Sample name (mm) (sec) (cm/min) (mm) (sec) (cm/min) (mm) (sec) (cm/min) Example 3 0 0 non- 0 0 non- 0 0 non- flammable flammable flammable Comparative 266 100 16.0 256 98 15.7 268 92 17.5 Example 7 Comparative 0 0 non- 0 0 non- 0 0 non- Example 8 flammable flammable flammable Comparative 270 190 8.5 270 201 8.1 265 189 8.4 Example 9

(60) TABLE-US-00012 TABLE 6 Sample name Light resistance Heat resistance Feeling Example 3 grades 4 to 5 Good Comparative Example 7 grades 4 to 5 Good Comparative Example 8 grades 4 to 5 Slightly hard Comparative Example 9 grades 4 to 5 Good

Effect of the Invention

(61) According to the present invention, synthetic leather can be flame retarded without using a halogen-based flame retardant. In addition, the flame retardant synthetic leather obtained by the present invention does not deteriorate in light resistance, heat resistance and feeling.

INDUSTRIAL APPLICABILITY

(62) The flame retardant synthetic leather of the present invention is useful as a material for car interior products (such as seats, headrests, tonneau covers, sun visors and ceilings) and furniture (such as chairs and sofas).