U.S. patent application number 10/570366 was filed with the patent office on 2007-01-11 for flame-retardant sheet and formed article therefrom.
Invention is credited to Morimichi Hirano, Kuninori Ito, Masanori Ogawa.
Application Number | 20070009723 10/570366 |
Document ID | / |
Family ID | 37618636 |
Filed Date | 2007-01-11 |
United States Patent
Application |
20070009723 |
Kind Code |
A1 |
Ogawa; Masanori ; et
al. |
January 11, 2007 |
Flame-retardant sheet and formed article therefrom
Abstract
The object of the present invention is to provide a highly fire
resistant fiber sheet and a molded fiber sheet thereof. The fibers
of the fire resistant sheet of the present invention contain
expandable graphite. When said expandable graphite is exposed to
high temperatures, it will expand, giving self-extinguishing
properties to said fiber sheet. Since said fire resistant molded
fiber sheet is highly fire resistant and nontoxic to humans and
animals, it is useful for car or building interiors, and the
like.
Inventors: |
Ogawa; Masanori; (Aichi,
JP) ; Ito; Kuninori; (Aichi, JP) ; Hirano;
Morimichi; (Aichi, JP) |
Correspondence
Address: |
Donald S. Dowden;Cooper & Dunham
1185 Avenue of the Americas
New York
NY
10036
US
|
Family ID: |
37618636 |
Appl. No.: |
10/570366 |
Filed: |
August 20, 2004 |
PCT Filed: |
August 20, 2004 |
PCT NO: |
PCT/JP04/12339 |
371 Date: |
March 2, 2006 |
Current U.S.
Class: |
428/292.1 |
Current CPC
Class: |
B32B 5/26 20130101; D04H
1/435 20130101; E04B 1/941 20130101; D04H 1/425 20130101; D04H
1/43914 20200501; Y10T 428/249924 20150401; D06N 3/0063 20130101;
D04H 1/587 20130101; B32B 2264/108 20130101; B32B 2250/02 20130101;
B60R 13/08 20130101; D06M 11/74 20130101; B32B 2260/023 20130101;
D04H 1/48 20130101; B32B 2250/20 20130101; B32B 2262/0276 20130101;
B32B 2307/3065 20130101; B32B 27/12 20130101; B32B 2262/0253
20130101; B32B 2419/00 20130101; B32B 27/20 20130101; D04H 1/64
20130101; B32B 2605/00 20130101; B32B 2260/046 20130101 |
Class at
Publication: |
428/292.1 |
International
Class: |
D04H 3/00 20060101
D04H003/00 |
Claims
1. A resistant fiber sheet wherein unexpanded expandable graphite
is contained in fibers.
2. A fire resistant fiber sheet in accordance with claim 1, wherein
said fibers are hollow, or hollow fibers are contained in said
fibers.
3. A fire resistant fiber sheet in accordance with claim 1, wherein
fibers having a low melting point of below 180.degree. C. are mixed
into said fibers.
4. A fire resistant fiber sheet in accordance with claim 1, wherein
said fibers are bound with a synthetic resin binder.
5. A fire resistant fiber sheet in accordance with claim 4, wherein
said synthetic resin binder is water soluble, and water solution of
said synthetic resin binder in which said expandable graphite is
dispersed, is impregnated into said fiber sheet.
6. A fire resistant fiber sheet in accordance with claim 5, wherein
a water soluble synthetic resin is dissolved in said water
solution.
7. A fire resistant fiber sheet in accordance with claim 5, wherein
said synthetic resin binder is a phenol group resin, and said
phenol group resin is sulfomethylated and/or sulfimethylated.
8. A molded fiber sheet made by molding said fire resistant fiber
sheet in accordance with claim 1 into a prescribed shape.
9. A molded fiber sheet in accordance with claim 8, wherein the
ventilation resistance of said molded fiber sheet is in the range
of between 0.1 and 100 kPas/m.
10. A laminated sheet, wherein other fiber sheet(s) is/are
laminated on one or both side(s) of said fire resistant fiber sheet
in accordance with claim 1, with an intermediating porous
thermoplastic resin film.
11. A molded laminated sheet made by molding said laminated sheet
in accordance with claim 10, into a prescribed shape.
12. A molded laminated sheet in accordance with claim 11, wherein
the ventilation resistance of said molded laminated sheet is in the
range of between 0.1 and 100 kPas/m.
13. A fire resistant fiber sheet in accordance with claim 2,
wherein said fibers are bound with a synthetic resin binder.
14. A fire resistant fiber sheet in accordance with claim 3,
wherein said fibers are bound with a synthetic resin binder.
15. A fire resistant fiber sheet in accordance with claim 6,
wherein said synthetic resin binder is a phenol group resin, and
said phenol group resin is sulfomethylated and/or
sulfimethylated.
16. A molded fiber sheet made by molding said fire resistant fiber
sheet in accordance with claim 2 into a prescribed shape.
17. A molded fiber sheet made by molding said fire resistant fiber
sheet in accordance with claim 3 into a prescribed shape.
18. A laminated sheet, wherein other fiber sheet(s) is/are
laminated on one or both side(s) of said fire resistant fiber sheet
in accordance with claim 2, with an intermediating porous
thermoplastic resin film.
19. A laminated sheet, wherein other fiber sheet(s) is/are
laminated on one or both side(s) of said fire resistant fiber sheet
in accordance with claim 3, with an intermediating porous
thermoplastic resin film.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a fire resistant fiber
sheet and a molded fiber sheet thereof, used for car or building
interiors, and the like.
BACKGROUND OF THE INVENTION
[0002] Hitherto, for instance, needled nonwoven fabric, or needled
felt, which are made by needle punching intertwining fibers, and
resin nonwoven fabric, or resin felt, which is made by binding
fibers with synthetic resin, or fiber knitting and fabric, and the
like have been provided.
[0003] JP 11-61616 JP 8-39596
[0004] In said fiber sheet, fire resistance as well as sound proof
and insulation properties are necessary.
[0005] To give said fiber sheet a fire resistance property, a fire
retardant, such as tetrachlorophthalic acid, tetrabromophthalic
acid, tetrabromobis phenol A, antimony trioxide, chlorinated
paraffin, and the like are contained in said fiber sheet.
[0006] Said fire retardants cannot, however, guarantee an adequate
fire resistance of said fiber sheet, and are feared to be
toxic.
DISCLOSURE OF THE INVENTION
[0007] The present invention provides a fire resistant fiber sheet
wherein expandable graphite is contained, as a means of solving
said problems in the prior art.
[0008] Preferably said fibers are hollow, or hollow fibers are
contained in said fibers, and preferably fibers having a low
melting point of below 180.degree. C. are mixed into said
fibers.
[0009] It is preferable that said fibers are bound with a synthetic
resin binder, which is preferably water soluble, and that a water
solution of said synthetic resin binder, in which said expandable
graphite is dispersed, is impregnated into said fiber sheet. In
this case preferably a water soluble synthetic resin is dissolved
in said water solution, and it is preferable that the synthetic
resin binder is phenol group resin and that said phenol group resin
is sulfomethylated and/or sulfimethylated.
[0010] Further, the present invention provides a molded fiber sheet
made by molding said fire resistant fiber sheet into a prescribed
shape.
[0011] Preferably the ventilation resistance of said molded fiber
sheet is in the range of between 0.1 and 100 kPas/m.
[0012] Furthermore, the present invention provides a laminated
sheet wherein other fiber sheet(s) is/are laminated on one or both
side(s) of said fire resistant fiber sheet with- an intermediating
porous thermoplastic resin film. Still further, the present
invention provides a molded laminated sheet made by molding said
laminated sheet into a prescribed shape.
[0013] Preferably a ventilation resistance of said molded laminated
sheet is in the range of between 0.1 and 100 kPas/m.
[ACTION]
[0014] When said fire resistant sheet of the present invention is
exposed to a high temperature, said expandable graphite expands,
giving a self fire extinguishing property to said fiber sheet. In a
case where said fibers are hollow or hollow fibers are contained in
said fibers, the rigidity of said fiber sheet is improved. Further,
in a case where said fibers, having a low melting point of below
180.degree. C., are contained in said fibers, or where said fibers
are bound with a synthetic resin binder, said fiber sheet becomes
moldable. Commonly, said synthetic resin binder is water soluble,
and a water solution of said synthetic resin binder in which said
expandable graphite is dispersed, is impregnated into said fiber
sheet, and in a case where said water soluble synthetic resin is
dissolved in said water solution, said water solution is thickened
to prevent the sedimentation of said expandable graphite, and the
adhesiveness of said expandable graphite to fibers is improved.
Further, said water soluble synthetic resin also acts as a release
agent, so that the resulting molded fiber sheet is easily released
from the mold.
[EFFECT OF THE INVENTION]
[0015] Said fiber sheet of the present invention has excellent fire
resistance and no toxicity to humans and animals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a side view to illustrate the principle of the
measurement of ventilation resistance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The present invention is detailed as described below.
[Fiber]
[0018] The fiber used in the present invention includes synthetic
fibers such as polyester fiber, polyamide fiber, acrylic fiber,
urethane fiber, polyvinylchloride fiber, polyvinylidene chloride
fiber, acetate fiber, and the like, natural fibers such as wool,
mohair, cashmere, camel hair, alpaca, vicuna, angora, silk, raw
cotton, cattail fiber, pulp, cotton, coconut fiber hemp fiber,
bamboo fiber, kenaf fiber, and the like, cellulose group synthetic
fibers such as rayon fiber, staple fiber, polynosic fiber,
cuprammonium rayon fiver, acetate fiber, triacetate fiber, and the
like, inorganic fibers such as glass fiber, carbon fiber, ceramic
fiber, asbestos fiber, and the like, and reclaimed fibers obtained
by the fiberizing of fiber product made of said fibers. Said fiber
is used singly or two or more kinds of said fiber may be used in
combination in the present invention. Further, hollow fiber is
preferable. Said hollow fiber is made of polyester, such as
polyethylent telephthalate, polybutylene telephthalate,
polyhexamethylene telephthalate, poly 1.4-dimethylcyclohexane
telephthalate, and the like, poliamide such as nylon 6, nylon 66,
nylon 46, nylon 10, and the like, polyolefine such as polyethylene,
polypropylene, and the like, thermoplastic resin such as an acrylic
resin, polyurethane, polyvinylchloride, polyvinylidene chloride,
acetate, and the like. Said hollow fiber is used singly or two or
more kinds of said fiber may be used in combination.
[0019] Said hollow fiber is made by the well known method such as
the melt spinning method, and a method wherein two kinds of
thermoplastic resins are melt spun together to produce a combined
fiber, after which one of said two kinds of thermoplastic resin is
selectively removed by dissolving it from said combined fiber.
[0020] One or more tuberous hollow part(s) whose cross section(s)
is/are circular, elliptical, or the like is (are) formed in said
hollow fiber, the ratio of hollow part(s) in said hollow fiber
commonly being 5% to 70%, but preferably 10% to 50%. Said ratio of
hollow part(s) indicates the rate of the cross section area of
tuberous hollow part(s) to the cross section area of said fiber.
Further, the fineness of said hollow fiber is in the range of
between ldtex and 50 dtex, but preferably between 2 dtex and 20
dtex.
[0021] In a case where said hollow fibers are mixed in with common
fibers, said hollow fibers are preferably mixed in with common
fibers in an amount of more than 30% by mass.
[0022] When said hollow fibers are used in said fiber sheet, the
rigidity of said fiber sheet is improved by the tube effect of said
hollow fibers.
[0023] Further, in the present invention, fiber having a low
melting point of below 180.degree. C. may be used. Said low melting
point fibers include, for example, polyolefine group fibers such as
polyethylene fiber, polypropylene fiber ethylene-vinyl acetate
copolymer fiber, ethylene-ethyl acrylate copolymer fiber, and the
like, polyvinylchloride fiber, polyurethane fiber, polyester fiber,
polyester copolymer fiber, polyamide fiber, polyamide copolymer
fiber, and the like. Said fiber having a low melting point may be
used singly, or two or more kinds of said fiber may be used in
combination. The fineness of said low melting point fiber is
commonly in the range of between 0.1 dtex and 60 dtex. Commonly,
said low melting point fibers are mixed in with common fibers in an
amount of 1 to 50% by mass.
[Expandable Graphite]
[0024] Said expandable graphite used in the present invention is
made by dipping natural graphite into a mixture of mineral acids,
such as sulfuric acid, nitric acid, and the like, and then adding
an oxidizing reagent, such as hydrogen peroxide, hydrochloric acid,
with an expansion start temperature of about 150.degree. C. to
300.degree. C., and an expansion volume of about 30 to 300 ml/g,
with a particle size of about 30 to 300 mesh.
[0025] Said expandable graphite may be added to said fiber sheet by
dispersing said expandable graphite in a synthetic resin binder in
a case where said synthetic resin binder is emulsion or latex type,
impregnating said fiber sheet with said resin binder, or said resin
binder is impregnated into said fiber sheet, after which a water
solution of a water soluble synthetic resin or an emulsion of an
alkali soluble synthetic resin, in which expandable graphite is
dispersed, is prepared to coat or impregnate into said fiber sheet,
said water soluble synthetic resin being such as polysodium
acrylate, partially saponified product of polyacrylic ester,
polyvinyalcohol, carboxymethyl cellulose, methyl cellulose, ethyl
cellulose, hydroxyethyl cellulose, and the like, said alkali
soluble synthetic resin being such as copolymer of acrylic ester
and/or methacrylic ester, and acrylic acid and/or methacrylic acid,
said copolymer being slightly cross-linked.
[0026] Said expandable graphite is preferably dispersed in said
synthetic resin binder, synthetic resin emulsion, or synthetic
resin water solution with a homogenizer, ultrasonic emulsifying
apparatus, or the like.
[0027] In a case where said ultrasonic emulsifying apparatus is
used, said expandable graphite is very finely and uniformly
dispersed in said water solution or said emulsion, and in a case
where said synthetic resin binder in which said expandable graphite
is uniformly dispersed, is impregnated into said fiber sheet, said
expandable graphite may easily penetrate deeply said fiber sheet,
improving the fire resistance of said fiber sheet.
[Thermally Expandable Particles]
[0028] In the present invention, thermally expandable particles may
be added to said fiber sheet if desired. Said thermally expandable
particles consist of a thermoplastic resin having a low softening
point, and a solvent having a low boiling point. Said thermoplastic
resin having a low softening point may include, a (co)polymer of
one or more kinds of monomer, for example, aliphatic or cyclic
acrylate such as methyl acrylate, ethyl acrylate, n-propyl
acrylate, iso-propyl acrylate, n-buthyl acrylate, iso-buthyl
acrylate, t-buthyl acrylate, 2-ethyl-hexyl acrylate, cyclohexyl
acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl
methacrylate, n-propyl methacrylate, iso-propyl methacrylate,
n-buthyl methacrylate, iso-buthyl methacrylate, 2-ethyl hexyl
methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl
methacrylate, stearyl methacrylate, lauryl methacrylate, and the
like; and/or methacrylate; vinyl ether such as methyl vinyl ether,
ethyl vinyl ether, n-propyl vinyl ether, n-buthyl vinyl ether,
iso-buthyl vinyl ether, and the like; a styrenic monomer such as
styrene, .alpha.-methyl styrene, and the like; a nitrile group
monomer such as acrylonitrile, methacrylonitrile, and the like; a
halogen aliphatic acid vinyl monomer such as vinyl acetate,
propionic acid vinyl, and the like; a halogen containing vinyl
monomer such as vinyl chloride, vinylidene chloride, vinyl
fluoride, vinylidene fluoride, and the like; an olefin group
monomer such as ethylene, propylene, and the like; a diene group
monomer such as isoprene, chloroprene, butadiene, and the like;
.alpha.,.beta.-unsaturated carboxylic acid such as acrylic acid,
methacrylic acid, itaconic acid, maleic acid, crotonic acid,
atropic acid, citraconic acid, and the like; a hydroxyl group
cotaining monomer such as 2-hydroxy ethyl methacrylate, 2-hydroxy
ethyl acrylate, 2-hydroxy propyl methacrylate, 2-hydroxy propyl
acrylate, allyl alcohol, and the like; an amide group vinyl monomer
such as acrylic amide, methacrylamide, diaceton acrylic amide, and
the like; an amino group containing vinyl monomer such as
dimethylamino ethyl methacrylate, dimethylamino ethyl acrylate,
dimethylamino propyl methacrylate, dimethylamino propyl acrylate,
and the like; an epoxy group containing vinyl monomer such as
glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether, and
the like; further, water soluble vinyl monomer such as vinyl
pyrrolidone, vinyl pyridine, vinyl carbazole and the like ; a
hydrolyzable silyl group containing vinyl monomer such as
.gamma.-methacryloxy propyl tri methoxysilane, vinyl tri
acetoxysilane, p-tri methoxy cyril styrene, p-tri ethoxy cyril
styrene, p-tri methoxy cyril-.alpha.-methyl styrene, p-tri ethoxy
cyril-.alpha.-methyl styrene, .gamma.-acryloxy propyl tri
methoxysilane, vinyl tri methoxysilane, N-.beta.(N-vinyl benzyl
amino ethyl-.gamma.-amino propyl) tri methoxysilane, hydrochloride,
and the like; and crosslinked (co)polymer of said (co)polymer
crosslinked with a cross-linking agent such as divinyl benzene,
polyvalent acrylate such as diethyleneglycol diacrylate and the
like; metacrylate, diathylphthelate, allyl glycidyl ether, and the
like; thermoplastic resin having softening point desirably below
180.degree. C., such as a low softening point polyamid, low
softening point polyester, and the like.
[0029] Said low boiling point solvent may include organic solvents
having a boiling point below 150.degree. C., such as n-hexane,
cyclohexane, n-pentane, iso-pentane, n-butane, iso-butane,
n-heptane, n-octane, iso-octane, gasoline, ethyether, acetone,
benzene, and the like.
[0030] Said thermally expandable particles are made of expandable
beads, wherein said low boiling point solvent is impregnated into
said thermoplastic resin beads, microcapsules, wherein said low
boiling point solvent is sealed in a shell of said thermoplastic
resin, having a low softening point, and the like. Commonly, said
particles have a diameter in the range of between 0.5 and 1000
.mu.m.
[0031] Further, thermoexpandable inorganic particles such as
vermiculite perlite, shirasu balloon, and the like may be used as
said thermally expandable particles of the present invention.
[Fiber Sheet]
[0032] Said fiber sheet of the present invention may be
manufactured by a method in which sheet or mat of fiber web is
intertwined by the needle punching, a method in which sheet or mat
of fiber web is bound by mixing low melting point fibers into said
sheet or mat or impregnating a synthetic resin binder into said
sheet or mat, or a method in which sheet or mat of fiber web is
intertwined by the needle punching, after which said synthetic
resin binder is impregnated into said needle punched sheet or mat,
or a method in which fibers are knitted or woven, or the like.
[0033] Said expandable graphite or thermally expandable particles
may be mixed into said fibers before sheet or mat is made from said
fibers, or in a case where said synthetic resin binder is
impregnated or mixed into said sheet or mat, said expandable
graphite or said thermally expandable particles may be mixed into
said synthetic resin binder. The mixing ratio of said expandable
graphite or thermally expandable particles may be arbitrary, but
usually, said expandable graphite is added to said fibers in an
amount in the range of between 0.5 and 50% by mass, and in a case
where said thermally expandable particles are used together with
said expandable graphite, said particles may be added to said
fibers in an amount in the range of between 0.1 to 50% by mass.
[0034] After said synthetic resin solution is impregnated or mixed
into said fiber sheet, said fiber sheet may be dried. In a case
where said synthetic resin binder contained in said fiber sheet is
a thermosetting resin, when said thermosetting resin is put in
B-stage, said fiber sheet can be stored for a long time and
moreover, said fiber sheet can be molded at a low temperature in a
short time.
[Synthetic Resin Binder]
[0035] Synthetic resin used as a binder for said fibers includes,
for example, thermoplastic synthetic resin such as polyethylene,
polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate
copolymer, polyvinylchloride, polyvinylidenechloride, polystyrene,
polyvinylacetate, fluoric resin, acrylic acid resin, thermoplastic
polyester, thermoplastic polyamide, thermoplastic urethane resin,
acrylonitrile-butadiene copolymer, styrene-butadiene copolymer,
acrylonitrile-butadiene-styrene copolymer, ethylene-propylene
copolymer, ethylene-propylene terpolymer, ethylene vinyl acetate
copolymer, and the like; thermosetting resins such as urethane
resin, melamine resin, heat hardening type acrylic acid resin, urea
resins, phenolic resin, epoxy resin, heat hardening type polyester,
and the like, and further, a synthetic resin precursor which
produces said synthetic resin such as prepolymer, oligomer monomer,
and the like may be used. Said prepolymer, ologomer or monomer may
include urethane resin prepolymer, epoxy resin prepolymer, melamine
resin prepolymer, urea resin prepolymer, phenol resin prepolymer,
diallyl phthalate prepolymer, acrylic oligomer, polyisocyanate,
methacryl ester monomer, diallyphthalated monomer, and the
like.
[0036] Said synthetic resin binder may be used singly or two or
more kinds of said synthetic resin may be used together, and said
synthetic resin binder may be commonly provided as an emulsion,
latex, water solution, organic solvent solution, and the like.
[0037] In a case where said synthetic resin binder is water
solution, water soluble resin is preferably dissolved in said water
solution. Said water soluble resin may include such as polysodium
acrylate, partial saponified polyacrylate, polyvinylalcohol,
carboxy methyl cellulose, methyl cellulose, ethyl cellulose,
hydroxyl ethyl cellulose, and the like. Further, an alkali soluble
resin such as copolymer of acrylic acid ester and/or methacrylic
acid ester and acrylic acid and/or methacrylic acid or a slightly
cross-linked copolymer of the above mentioned copolymer, and the
like may be used as said water soluble resin of the present
invention. Said copolymer or said slightly cross-linked copolymer
is commonly provided as an emulsion.
[0038] In a case where said water soluble resin is dissolved in
said synthetic resin water solution, said water solution may be
thickened to improve the stability of dispersion so that said
expandable graphite may become difficult to sediment, and uniform
dispersion can be prepared.
[0039] Further, the adhesiveness of said expandable graphite to
said fibers may be improved by said water soluble resin, to prevent
the release of said expandable graphite from said fiber sheet.
[0040] Said water soluble resin may be commonly added to said water
solution in an amount in the range of between 0.1 and 20% by mass
as a solid.
[0041] To impregnate said synthetic resin into said fiber sheet,
said fiber sheet is usually dipped into liquid synthetic resin or
synthetic resin solution, or said liquid synthetic resin or said
synthetic resin solution is coated on said fiber sheet by spraying,
or by using a knife coater, roll coater, flow coater, or the
like.
[0042] To adjust the synthetic resin content in said fiber sheet
into which said synthetic resin is impregnated or mixed, said sheet
may be squeezed using a squeezing roll or press machine after said
synthetic resin has been impregnated or mixed into said fiber
sheet. As a result of said squeezing process, the thickness of said
fiber sheet may be reduced but in a case where said hollow fibers
are contained in said fiber sheet, said fiber sheet has high
rigidity, so that the thickness of said fiber sheet may be restored
elastically after squeezing, to ensure adequate thickness of said
fiber sheet. In particular, in a case where said low melting point
fibers are contained in said fiber sheet, it is desirable to heat
said fiber sheet and melt said low melting point fibers, so as to
bind the fibers with said melted fibers. Thus, the rigidity and
strength of said fiber sheet is improved, so that the workability
of said fiber sheet during the process of impregnating it with said
synthetic resin may be improved, resulting in a remarkable
restoration of the thickness of said fiber sheet after
squeezing.
[0043] As described above, in a case where said hollow fibers are
contained in said fiber sheet, said fiber sheet may be rigid, so
that the content of said synthetic resin binder in said fiber sheet
can be reduced, compared with said fiber sheet containing no-hollow
fibers.
[0044] In a case where said synthetic binder is an aqueous
synthetic resin emulsion, it is desirable to disperse said
expandable graphite into said aqueous synthetic resin emulsion
using an ultra sonic effect. In this case, said ultrasonic wave's
length is desirably in the range of between 10 and 700 kH.sub.2.
When said ultrasonic wave is effected on said aqueous synthetic
resin emulsion, said expandable graphite may become very fine, and
said very fine graphite can be impregnated into the inside of said
fiber sheet.
[0045] A desirable synthetic resin binder used in the present
invention is phenol group resin. Said phenol group resin used in
the present invention is described below.
[0046] A phenol group resin is produced by the condensation
reaction between phenolic compound and an aldehyde and/or aldehyde
donor. Said phenol group resin may be sulfoalkylated and /or
sulfialkylated to improve its water solubility.
[0047] Said phenol group resin is impregnated into a green fiber
sheet in the form of a precondensation polymer. Commonly, said
precondensation polymer is prepared as a water solution, but if
desired, a water-soluble organic solvent can also be used in the
present invention. Said water-soluble organic solvent may be an
alcohol such as methanol, ethanol, isopropanol, n-propanol,
n-butanol, isobutanol, sec-butanol, t-butanol, n-amyl alcohol,
isoamyl alcohol, n-hexanol, methylamyl alcohol, 2-ethyl butanol,
n-heptanol, n-octanol, trimethylnonylalcohol, cyclohexanol, benzyl
alcohol, furfuryl alcohol, tetrahydro furfuryl alcohol, abiethyl
alcohol, diacetone alcohol, and the like; ketones such as acetone,
methyl acetone, methyl ethyl ketone, methyl-n-propyl ketone,
methyl-n-butyl ketone, methyl isobutyl ketone, diethyl ketone,
di-n-propyl ketone, diisobutyl ketone, acetonyl acetone, methyl
oxido, cyclohexanone, methyl cyclohexanone, acetophenon, camphor,
and the like; glycols such as ethylene glycol, diethylene glycol,
triethylene glycol, propylene glycol, trimethylene glycol,
polyethylene glycol, and the like; glycol ethers such as ethylene
glycol mono-methyl ether, ethylene glycol mono-ethyl ether,
ethylene glycol isopropyl ether, diethylene glycol mono-methyl
ether, triethylene glycol mono-methyl ether, and the like; esters
of the above mentioned glycols such as ethylene glycol diacetate,
diethylene glycol mono-ethyl ether acetate, and the like, and their
derivatives; ether such as 1,4-dioxane, and the like; diethyl
cellosolve, diethyl carbitol, ethyl lactate, isopropyl lactate,
diglycol diacetate, dimethyl formamide, and the like.
(Phenol Group Compound)
[0048] The phenolic compound used to produce said phenolic resin
may be monohydric phenol, or polyhydric phenol, or a mixture of
monohydric phenol and polyhydric phenol, but in a case where only
monohydric phenol is used, formaldehyde is apt to be emitted when
or after said resin composition is cured, so that polyphenol or a
mixture of monophenol and polyphenol is desirably used.
(Monohydric Phenol)
[0049] The monohydric phenols include alkyl phenols such as
o-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol,
xylenol, 3,5-xylenol, butylphenol, t-butylphenol, nonylphenol and
the like; monohydric derivatives such as o-fluorophenol,
m-fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol,
p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol,
o-iodophenol, m-iodophenol, p-iodophenol, o-aminophenol,
m-aminophenol, p-aminophenol, o-nitrophenol, m-nitrophenol,
p-nitorophenol, 2,4-dinitorophenol, 2,4,6-trinitorophenol and the
like; monohydric phenols of polycyclic aromatic compounds such as
naphthol and the like. Each monohydric phenol can be used singly,
or as a mixture thereof.
(Polyhydric Phenol)
[0050] The polyhydric phenols mentioned above, include resorsin,
alkylresorsin, pyrogallol, catechol, alkyl catechol, hydroquinone,
alkyl hydroquinone, fluoroglrsin, bisphenol, dihydroxynaphthalene
and the like. Each polyhydric phenol can be used singly, or as a
mixture thereof. Resorsin and alkylresorsin are more suitable than
other polyhydric phenols. Alkylresorsin is in particular the most
suitable polyhydric phenols because alkylresorsin can react with
aldehydes more rapidly than resorsin.
[0051] The alkylresorsins include 5-methyl resorsin, 5-ethyl
resorsin, 5-propyl resorsin, 5-n-butyl resorsin, 4,5-dimethyl
resorsin, 2,5-dimethyl resorsin, 4,5-diethyl resorsin, 2,5-diethyl
resorsin, 4,5-dipropyl resorsin, 2,5-dipropyl resorsin,
4-methyl-5-ethyl resorsin, 2-methyl-5-ethyl resorsin,
2-methyl-5-propyl resorsin, 2,4,5-trimethyl resorsin,
2,4,5-triethyl resorsin, and the like.
[0052] A polyhydric phenol mixture produced by the dry distillation
of oil shale, which is produced in Estonia, is inexpensive and said
polyhydric phenol mixture includes 5-metylresorcin, along with many
other kinds of alkylresorcin, being highly reactive, making said
polyhydric phenol mixture an especially desirable raw polyphenol
material.
[0053] In the present invention, said phenolic compound and
aldehyde and/or aldehyde donor (aldehydes) are condensed together.
Said aldehyde donor refers to a compound or a mixture which emits
aldehyde when said compound or said mixture decomposes. The
aldehydes include formaldehyde, acetoaldehyde, propionaldehyde,
chloral, furfural, glyoxal, n-butylaldehyde, caproaldehyde,
allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, phenyl
acetoaldehyde, o-tolualdehyde, salicylaldehyde and the like. The
aldehyde donors include paraformaldehyde, tiroxane,
hexamethylenetetramine, tetraoxymethylene, and the like.
[0054] As described above, said phenolic resin is desirably
sulfoalkylated and/or sulfialkylated, to improve the stability of
said water soluble phenolic resin.
(Sulfomethylation Agent)
[0055] The sulfomethylation agents used to improve the stability of
the aqueous solution of phenol resins, include such as water
soluble sulfites prepared by the reaction between sulfurous acid,
bisulfurous acid, or metabisulfirous acid, and alkaline metals,
trimethyl amine, quaternary ammonium (e.g.
benzyltrimethylammonium); and aldehyde additions prepared by the
reaction between said water soluble sulfites and aldehydes.
[0056] The aldehyde additions are prepared by the addition reaction
between aldehydes and water soluble sulfites as mentioned above,
wherein the aldehydes include formaldehyde, acetoaldehyde,
propionaldehyde, chloral, furfural, glyoxal, n-butylaldehyde,
caproaldehyde, allylaldehyde, benzaldehyde, crotonaldehyde,
acrolein, phenyl acetoaldehyde, o-tolualdehyde, salicylaldehyde,
and the like. For example, hydroxymethane sulfonate, which is one
of the aldehyde additions, is prepared by the addition reaction
between formaldehyde and sulfite.
(Sulfimethylation Agent)
[0057] The sulfimethylation agents used to improve the stability of
the aqueous solution of phenol resins, include alkaline metal
sulfoxylates of aliphatic or aromatic aldehyde such as sodium
formaldehyde sulfoxylate (a.k.a. Rongalit), sodium benzaldehyde
sulfoxylate, and the like; hydrosulfites (a.k.a. dithionites) of
alkaline metal or alkaline earth metal such as sodium hydrosulfite,
magnesium hydrosulfite and the like; hydroxyalkanesulfinate such as
hydroxymethanesulfinate and the like.
[0058] In the case of producing said phenol resins, if necessary,
additives may be mixed in with said phenol resins as a catalyst or
to adjust the pH. Such additives include acidic compounds and
alkaline compounds. Said acidic compounds include inorganic acid or
organic acid such as hydrochloric acid, sulfuric acid,
orthophosphoric acid, boric acid, oxalic acid, formic acid, acetic
acid, butyric acid, benzenesulfonic acid, phenolsulfonic acid,
p-toluenesulfonic acid, naphthalene-.alpha.-sulfonic acid,
naphthalenes-.beta.-sulfonic acid, and the like; esters of organic
acid such as dimethyl oxalate, and the like; acid anhydrides such
as maleic anhydride, phthalic anhydride, and the like; salts of
ammonium such as ammonium chloride, ammonium sulfate, ammonium
nitrate, ammonium oxalate, ammonium acetate, ammonium phosphate,
ammonium thiocyanate, ammonium imidosulfonate, and the like;
halogenated organic compounds such as monochloroacetic acid, the
salt thereof, organic halogenides such as
.alpha.,.alpha.'-dichlorohydrin, and the like; hydrochloride of
amines such as triethanolamine hydrochloride, aniline
hydrochloride, and the like; urea adducts such as the urea adduct
of salicylic acid, urea adduct of stearic acid, urea adduct of
heptanoic acid, and the like; and N-trimethyl taurine, zinc
chloride, ferric chloride, and the like.
[0059] Alkaline compounds include ammonia, amines; hydroxides of
alkaline metal and alkaline earth metal such as sodium hydroxide,
potassium hydroxide, barium hydroxide, calcium hydroxide, and the
like; oxide of alkaline earth metal such as lime, and the like;
salts of alkaline metal such as sodium carbonate, sodium sulfite,
sodium acetate, sodium phosphate, and the like.
(Method of Producing The Phenol Resins)
[0060] The phenol resins (the precondensation polymers) can be
prepared using the usual method. The usual methods include method
(a) comprising the condensation of a monohydric phenol and/or a
polyhydric phenol and aldehydes; method (b) comprising the
condensation of a precondensation polymer and a monohydric phenol
and/or a polyhyrdric phenol, wherein said precondensation polymer
comprises a monohydric phenol and aldehydes; method (c) comprising
the condensation of a precondensation polymer and a monohydric
phenol and/or a polyhydric phenol, wherein said precondensation
polymer comprises a monohydric phenol, a polyhydric phenol and
aldehydes; method (d) comprising the condensation of a
precondensation polymer consisting of a monohydric phenol and
aldehydes, and said precondensation polymer consisting of a
polyhydric phenol and aldehydes; and method (e) comprising the
condensation of a precondensation polymer consisting of a
monohydric phenol and aldehydes and/or precondensation polymers
consisting of a polyhydric phenol resin and aldehydes, and said
precondensation polymer consisting of monohydric phenol and
polyhydric phenol and aldehydes.
[0061] In the present invention, the desirable phenolic resin is
phenol-alkylresorcin cocondensation polymer. Said
phenol-alkylresorcin cocondensation polymer provides a water
solution of said cocondensation polymer (pre-cocondensation
polymer) having good stability, and being advantageous in that it
can be stored for a longer time at room temperature, compared with
a condensate consisting of a phenol only (precondensation polymer).
Further, in a case where said sheet material is impregnated with
said water solution by precuring, said material has good stability
and does not lose its moldability after longtime storage. Further,
since alkylresorcin is highly reactive to aldehyde, and catches
free aldehyde to react with it, the content of free aldehyde in the
resin can be reduced.
[0062] Said phenol-alkylresorcin cocondensation polymer is also
advantageous in that the content of free aldehyde in said polymer
is reduced by the reaction with alkylresorcin.
[0063] The desirable method for producing said phenol-alkylresorcin
cocondensation polymer is first to create a reaction between phenol
and aldehyde to produce a phenolic precondensation polymer, and
then to add alkylresorcin, and if desired, aldehyde, to said
phenolic precondensation polymer to create reaction.
[0064] In the case of method (a), for the condensation of
monohydric phenol and/or polyhydric phenol and aldehydes, the
aldehydes (0.2 mole to 3 moles) are added to said monohydric phenol
(1 mole), then said aldehydes (0.1 mole to 0.8 mole) are added to
the polyhydric phenol (1 mole) as usual. If necessary, additives
may be added to the phenol resins (the precondensation polymers).
In said method(s), there is a condensation reaction from heating at
55.degree. C. to 100.degree. C. for 8 to 20 hours. The addition of
aldehydes may be made at one time at the beginning of the reaction,
or several separate times throughout the reaction, or said
aldehydes may be dropped in continuously throughout the
reaction.
[0065] In the case of sulfomethylation and/or sulfimethylation, the
sulfomethylation agents and/or sulfimethylation agents may be added
to the precondensation at an arbitrary time.
[0066] The addition of the sulfomethylation agents and/or
sulfimethylation agents may be made any time, such as before,
during, or after condensation.
[0067] The total amount of said sulfomethylation agent and/or
sulfimethylation agent added is usually in the range of between
0.001 and 1.5 moles per lmole of phenol. In a case where said
amount added is less than 0.001 mole, the hydrophile of the
resulting sulfomethylated and/or sulfimethylated phenolic resin is
not adequate, and in a case where said amount added is more than
1.5 moles, the water resistance of the resulting sulfomethylated
and/or sulfimethylated phenolic resin degrades. To provide
excellent curing properties in the resulting precondensate and
excellent physical properties in the cured resin, said amount to be
added is preferably in the range of between 0.01 and 0.8 mole per 1
mole of phenol.
[0068] The sulfomethylation agents and/or sulfimethylation agents
for sulfomethylation and/or sulfimethylation react with the
methylol groups and/or aromatic groupes, so that the sulfomethyl
group and/or sulfimethyl group are introduced to the
precondensation prepolymers.
[0069] The solution of precondensation polymers of sulfomethylated
and/or sulfimethylated phenol resins is stable even in a wide range
of acidic condition (e.g. pH=1.0) or alkaline condition, so that
the solution can be cured in any conditions such as acid, neutral
or alkaline. In the case of curing the precondensate under acidic
condition, there is a decrease in the remaining methylol groups, so
that no formaldehydes from the decomposed cured phenol resins
appear.
[0070] Further, if necessary, the phenol resins and/or
precondensation polymers thereof may be copolycondensed with amino
resin monomers such as urea, thiourea, melamine, thiomelamine,
dicyandiamine, guanidine, guanamine, acetoguanamine,
benzoguanamine, 2,6-diamino-1.3-diamine, and the like.
[0071] Further, curing agents such as an aldehyde and/or an
aldehyde donor or an alkylol triazone derivative, and the like, may
be added to said phenolic precondensation polymer (including
precocondensation polymer).
[0072] As said aldehyde and/or aldehyde donor, the same aldehyde
and/or aldehyde donor as used in the production of said phenolic
precondensation polymer is (are) used, and an alkylol triazone
derivative is produced by the reaction between urea group compound,
amine group compound, and aldehyde and/or aldehyde donor. Said urea
group compound used in the production of said alkylol triazoned
derivative may be such as urea, thiourea, an alkylurea such as
methylurea, an alkylthiourea such as methylthiourea; phenylurea,
naphthylurea, halogenated phenylurea, nitrated alkylurea, and the
like, or a mixture of two or more kinds of said urea group
compounds. In particular, desirable urea group compound may be urea
or thiourea. As amine group compounds, aliphatic amine such as
methyl amine, ethylamine, propylamine, isopropylamine, butylamine,
amylamine and the like, benzylamine, farfuryl amine, ethanol amine,
ethylmediamine, hexamethylene diamine hexamethylene tetramine, and
the like, as well as ammonia are illustrated, and said amine group
compound is used singly or two or more amine group compounds may be
used together.
[0073] The aldehyde and/or aldehyde donor used for the production
of said alkylol triazone derivative is (are) the same as the
aldehyde and/or aldehyde donor used for the production of said
phenolic precondensation polymer.
[0074] To synthesize said alkylol triazone derivatives, commonly
0.1 to 1.2 moles of said amine group compound(s) and/or ammonia,
and 1.5 to 4.0 moles of aldehyde and/or aldehyde donor are reacted
with 1 mole of said urea group compound.
[0075] In said reaction, the order in which said compounds are
added is arbitrary, but preferably, first the required amount of
aldehyde and/or aldehyde donor is (are) put in a reactor, then the
required amount of amine group compound(s) and/or ammonia is (are)
gradually added to said aldehyde and/or aldehyde donor, the
temperature being kept at below 60.degree. C., after which the
required amount of said urea group compound(s) is (are) added to
the resulting mixture at 80 to 90.degree. C., for 2 to 3 hours,
being agitated to react together. Usually, 37% by mass of formalin
is used as said aldehyde and/or aldehyde donor, but some of said
formalin may be replaced with paraform aldehyde to increase the
concentration of the reaction product.
[0076] Further, in a case where hexamethylene tetramine is used,
the solid content of the reaction product obtained is much higher.
The reaction between said urea group compound, said amine group
compound and/or ammonia and said aldehyde and/or aldehyde donor is
commonly performed in a water solution, but said water may be
partially or wholly replaced by one or more kinds of alcohol(s)
such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol,
diethlene glycol, and the like, and one or more kinds of other
water soluble solvent(s) such as a ketone group solvent like
acetone, methylethyl ketone, and the like can also be used as
solvents.
[0077] The amount of said curing agent to be added is, in the case
of an aldehyde and/or aldehyde donor, in the range of between 10
and 100 parts by mass to 100 parts by mass of said phenolic
precondensation polymer (precocondensation polymer), and in the
case of alkylol triazone, 10 to 500 parts by mass to 100 parts by
mass of said phenolic precondensation polymer (precocondensation
polymer).
[0078] Into said synthetic resin binder used in the present
invention, further, inorganic fillers such as calcium carbonate,
magnesium carbonate, barium sulphate, calcium sulphate, sulfurous
acid calcium, calcium phosphate, calcium hydroxide, magnesium
hydroxide, aluminium hydroxide, magnesium oxide, titanium oxide,
iron oxide, zinc oxide, alumina, silica, diatomaceous earth,
dolomite, gypsum, talc, clay, asbestos, mica, calcium silicate,
bentonite, white carbon, carbon black, iron powder, aluminum
powder, glass powder, stone powder, blast furnace slag, fly ash,
cement, zirconia powder, and the like; natural rubber or its
derivative; synthetic rubber such as styrene-butadiene rubber,
acrylonitrile-butadiene rubber, chloroprene rubber,
ethylene-propylene rubber, isoprene rubber, isoprene-isobutylene
rubber, and the like; water-soluble macromolecule and natural gum
such as polyvinyl alcohol, sodium alginate, starch, starch
derivative, glue, gelatin, powdered blood, methyl cellulose,
carboxymethylcellulose, hydroxy ethyl cellulose, polyacrylate,
polyacrylamide, and the like; fillers such as calcium carbonate,
talc, gypsum, carbon black, wood flour, walnut powder, coconut
shell flour, wheat flour, rice flour, and the like; surfactants;
higher fatty acid such as stearic acid, palmitic acid, and the
like; fatty alcohol such as palmityl alcohol, stearyl alcohol, an d
the like; fatty acid ester such as butyryl stearate, glycerin mono
stearate and the like; fatty acid amide; natural wax or composition
wax such as carnauba wax, and the like; mold release agents such as
paraffin, paraffin oil, silicone oil, silicone resin, fluoric
resin, polyvinyl alcohol, grease, a nd the like; organic blowing
agents such as azodicarbonamido, dinitroso pentamethylene
tetramine, P,P'-oxibis(benzene sulfonylhydrazide),
azobis-2,2'-(2-methylglopionitrile), and the like; inorganic
blowing agents such as sodium bicarbonate, potassium bicarbonate,
ammonium bicarbonate and the like; hollow particles such as shirasu
balloon, perlite, glass balloon, foaming glass, hollow ceramics,
and the like; foaming bodies or particles such as foaming
polyethylene, foaming polystyrene, foaming polypropylene, and the
like; pigment; dye; antioxidant; antistatic agent; crystallizer;
fire retardants such as a phosphorus compound, nitrogen compound,
sulfur compound, boron compound, bromine compound, guanidine
compound, phosphate compound, phosphate ester compound, amino
resin, and the like; flameproof agent; water-repellent agent;
oil-repellent agent; insecticide agent; preservative; wax;
lubricants; antioxidants, ultraviolet stabilizers; plasticizers
such as phthalic ester (ex. dibutyl phthalate(DBP), dioctyl
phthalate(DOP), dicyclohexyl phthalate) and others(ex. tricresyl
phosphate), can be added or mixed.
[0079] Said fiber sheet of the present invention is molded in a
flat panel shape or other prescribed shape, and commonly hot-press
molding is applied for said molding, and in a case where thermally
expandable particles are contained in said fiber sheet, said
thermally expandable particles may expand with restricting the
thickness of said fiber sheet during hot-press molding In a case
where said thermally expandable particles are heated at a
temperature higher than the expansion temperature of said thermally
expandable particles, restricting the thickness of said fiber
sheet, said thermally expandable particles may expand. Since the
thickness of said fiber sheet is restricted as described above,
expanding particles may push the fibers surrounding said expanding
particles, compressing said fibers, resulting in the density of
said fiber sheet becoming higher, improving the rigidity of said
fiber sheet. The air space ratio of whole fiber sheet, however, may
not change, so that the weight of said fiber sheet may also remain
the same.
[0080] Said fiber sheet of the present invention may be hot-pressed
into a prescribed shape after said fiber sheet is hot-pressed into
a flat panel, and further, in a case where fibers having a low
melting point, or a thermoplastic resin binder is contained in said
fiber sheet, said fiber sheet may be heated to soften said low
melting point fibers or said thermoplastic resin, after which said
fiber sheet may be cold-pressed into a prescribed shape. A plural
number of said sheets are laminated upon molding.
[0081] Said sheet of the present invention is useful as a base
panel for the interior of a car, such as a head lining, dash
silencer, hood silencer, engine under cover silencer, cylinder head
cover silencer, dashouter silencer, floor mat, dash board, door
trim or reinforcement that is laminated on said base panel or sound
insulating material, heat insulating material, or building
material. The ventilation resistance of said molded sheet made of
said fiber sheet is preferably 0.1 to 100 kPas/m, wherein said
ventilation resistance R (Pas/m) is a barometer expressing the
degree of ventilation of said porous material. To measure said
ventilation resistance R, a stationary current pressure difference
method may be applied. As shown in FIG. 1, a test piece is arranged
in a cylindrical duct W, air being put in said duct at a constant
flow, as shown by an arrow, to measure the difference of the
pressure in said duct between inlet side P1, and outlet side
P2.
[0082] Ventilation resistance is calculated by the following
formula. R=.DELTA.P/V Wherein .DELTA.P is the difference in the
pressure Pa(.DELTA.P=P1-P2), and V represents the flowing volume of
the air for said unit cross section area of said duct
(m.sup.3/m.sup.2S). Said ventilation resistance R (Pas/m) has the
following relationship with the ventilation degree C(m/Pas) of
C=1/R
[0083] Said ventilation resistance can be measured with such as the
ventilation tester (Tester Name: KES-F8-AP1, KATO TEC Co., Ltd. The
stationary current pressure difference method).
[0084] Said molded fiber sheet having a ventilation resistance in
the range of between 0.1 and 100 kPas/m has an excellent sound
absorption property.
[0085] Said fiber sheet may be laminated on to other sheet material
such as the surface sheet, back sheet, core sheet and the like and
further, other sheet(s) may be laminated on to one or both side(s)
of said fiber sheet of the present invention, intermediating a
porous thermoplastic resin film.
[0086] Said porous plastic sheet may be a film made of, for
example, polyolefine group resin such as polyethylene,
polypropylene, ethylene-vinyl acetate copolymer,
ethylene-ethylacrylate copolymer and the like (including modified
polyolefine group resin), polyvinylchloride, polyurethane,
polyester, polyester copolymer, polyamide, polyamide copolymer, and
the like, or a mixture of two or more kinds of said resins.
[0087] Said laminated sheet is manufactured by such as extrusion
molding a thermoplastic resin film using a T-die, and laminating
said thermoplastic resin film on a fire resistant fiber sheet,
further laminating other fiber sheet on said fiber sheet, then
hot-pressing said laminated sheet into a prescribed shape.
[0088] Said thermoplastic resin film may be porous, or may be
needled after laminating with said fire resistant fiber sheet to be
a porous thermoplastic resin film, but when said thermoplastic
resin film which has been extruded from the T-die, and softened by
heating, is laminated on said fiber sheet, and pressed, said
thermoplastic resin film may become porous, having a lot of fine
holes. Said holes in said thermoplastic resin film may be formed by
the shag on the surface of said fiber sheet. In this method, no
process is necessary to form holes in said film, and fine holes may
give the product an improved sound absorption property.
[0089] The ventilation resistance of said molded laminated sheet
manufactured by the molding of said laminated sheet is preferably
in the range of between 0.1 and 100 kPas/m. Said molded laminated
sheet has an excellent sound absorption property.
[0090] EXAMPLES of the present invention are described below.
However, the scope of the present invention should not be limited
by only said EXAMPLES.
EXAMPLE 1
[0091] A fiber sheet (unit weight: 500 g/m.sup.2, thickness: 15 mm)
was manufactured by the needle punching method, using a fiber web
containing 80% by mass of polyester fiber (fiber fineness: 12 dtex
fiver length : 52 mm) and 20% by mass of low-melting point
polyester fiber (softening point: 110.degree. C., fiber fineness: 8
dtex, fiber length : 54 mm). A treatment solution was prepared by
adding and mixing 20 parts by mass of expandable graphite
(expansion start temperature 300 to 320.degree. C., expansion rate:
100 times) to 80 parts by mass of phenol-formaldehyde
precondensation polymer (solid content 50% by mass). The viscosity
of said treatment solution was 100 mPas.
[0092] Said treatment solution was impregnated into said fiber
sheet in an amount of 50% by mass solid content, after which said
fiber sheet into which said treatment solution was impregnated, was
then dried in a drying chamber with decompression, at 100 to
120.degree. C. for 3 minutes, to precure said fiber sheet. Said
precured fiber sheet was then hot-pressed at 200.degree. C. for 60
seconds, to obtain a molded fiber sheet having a thickness of 10
mm. The ventilation resistance of the resulting molded fiber sheet
was measured using a ventilation tester (Tester Name: KES-F8-AP1,
KATO TECH Co., Ltd. V=4.times.10.sup.-2 (m/s). As a result, the
ventilation resistance of said molded fiber sheet was
3.5kPas/m.
EXAMPLE 2
[0093] A treatment solution was prepared by adding and mixing 20
parts by mass of polyvinylalcohol water solution (10% by mass of
solid content, saponification degree 98.5 mol %) and 20 parts by
mass of expandable graphite (expansion start temperature : 300 to
320.degree. C., expansion rate, 100 times) into 60 parts by mass of
phenol formaldehyde precondensation polymer (50% by weight solid
content). The viscosity of said treatment solution was 250 mPas.
Using said treatment solution, a molded fiber sheet having a
thickness of 10 mm was manufactured in the same manner as EXAMPLE
1. The ventilation resistance of the resulting molded fiber sheet
was measured using the same tester as used in EXAMPLE 1 was 4.1
kPas/m.
EXAMPLE 3
[0094] A treatment solution was prepared by adding and mixing 15
parts by mass of polyvinyl alcohol water solution (10% by mass
solid content, saponification degree 98.5 mol %), 4parts by mass of
PRIMAL, ASE-60 (Rohm and Haas Co., Trade Name) which is an emulsion
of slightly cross-linked ethyl acrylate-methacrylic acid copolymer
as an alkali soluble thickener, 20 parts by mass of expandable
graphite (expansion start temperature: 300 to 320.degree. C.,
expansion rate: 130 times), and 1 part by mass of ammonia water
(27% by mass) into 60 parts by mass of phenol-folmaldehyde
precondensation polymer water solution (50% by mass solid content).
The viscosity of the resulting treatment solution was 950
mPas/m.
[0095] By using said treatment solution, a molded fiber sheet
(thickness 10 mm) was manufactured in the same manner as EXAMPLE 1.
The ventilation resistance of the resulting molded fiber sheet was
measured using the same tester as used in EXAMPLE 1 was 4.6
kPas/m.
COMPARISON 1
[0096] In EXAMPLE 1, a molded fiber sheet having a thickness of 10
mm was manufactured in the same manner as in EXAMPLE 1, excepting
that a flame retardant containing phosphorous and nitrogen was used
instead of expandable graphite. The ventilation resistance of the
resulting molded fiber sheet was 3.3 kPas/m. A stability test and a
fire resistance test were carried out on said molded fiber sheets
manufactured in EXAMPLE 1, 2 and 3, and COMPARISON 1. Test methods
were as follows. [0097] The fire resistance test [0098] UL94: Using
a test piece having a length of 125 mm, and a thickness of 10 mm
using a method according to UL94 standard. [0099] FMVSS-302: Using
a test piece having a length of 350 mm, a width of 100 mm, and a
thickness of 10 mm using a method according to the FMVSS-302
method. [0100] Stability test of treatment solutions. Each
treatment solution was kept at a room temperature, and stability
being optically determined. The evaluation indicator is as follows.
.circleincircle.: stable uniform solution after 7 days standing.
.largecircle.: expandable graphite separates after 2 to 3 days
standing.
[0101] X: expandable graphite sediments and separates 10 to 20
minutes after the preparation of said treatment solution
TABLE-US-00001 TABLE 1 Fire retardancy Stability test of UL94
FMVSS-302 treatment solutions EXAMPLE 1 V-0 Nonflammability X
EXAMPLE 2 V-0 Nonflammability .largecircle. EXAMPLE 3 V-0
Nonflammability .circleincircle. EXAMPLE 4 Not passed
Nonflammability .circleincircle.
EXAMPLE 4
[0102] A fiber sheet (unit weight: 450 g/m.sup.2, thickness: 15 mm)
was manufactured by the needle punching method, using a fiber web
containing 50% by mass of hollow polyester fiber (hollow ratio:
20%, (fiber fineness: 7 dtes, fiber length: 60 mm), 20% by mass of
vinylon fiber (fiber fineness: 12 dte, fiber length: 45 mm) and 30%
by weight of hemp fiber (fiber fineness: 20 dtex, fiber length: 40
mm).
[0103] A treatment solution was prepared by mixing 50 parts by mass
of phenol-alkylresorcin-folmaldehyde precocondensation polymer (50%
by mass solid content), 17 parts by mass of carboxymethylcellulose
(1% by mass water solution), 5 parts by mass of PRIMAL ASE-60 as a
thickener, 27 parts by mass of expandable graphite (expansion start
temperature: 300.degree. C., expansion rate: 150 times), and 1 part
by mass of ammonia water (27% by mass), the viscosity of said
treatment solution being 200 mPas.
[0104] Said treatment solution was then impregnated into said fiber
sheet in an amount of 40% by mass solid content, after which said
fiber sheet into which said treatment solution was impregnated, was
then dried in the drying chamber at 100.degree. C. for 3 minutes
with decompression, to precure said fiber sheet. Said precured
fiber sheet was then hot-pressed at 220.degree. C. for 60 seconds,
to precure a molded fiber sheet having a thickness of 10 mm. The
fire resistance of the resulting molded sheet was V-0 according to
UL94 standard. Further, said treatment solution had excellent
workability without the sedimentation of the expandable graphite.
The ventilation resistance of said molded fiber sheet was 7.5
kPas/m.
EXAMPLE 5
[0105] A fiber sheet (unit weight: 400 g/m.sup.2, thickness 25 mm)
was manufactured by the needle punding method, using a fiber web
containing 60% by mass of hollow polyester fiber (hollow rate: 20%,
fiber fineness: 25 dtex, fiber length: 50 mm), 10% by mass of kenaf
fiber (fiber fineness 30 dtex, fiber length: 45 mm) and 30% by mass
of low melting point polyester fiber (softening point: 120.degree.
C., fiber fineness: 7 dtex, fiber length: 45 mm).
[0106] Twenty parts by mass of sulfomethylated phenol-alkyl
resorcin-formaldehyde precocondensation polymer (55% by mass solid
content), 1 part by mass of carbon black dispersion (30% by mass
solid content), 3 parts by weight of zirconium group water
repellent agent (40% by mass solid content), 20 parts by mass of
polyvinylalcohol (6% by mass solid content, saponification degree:
99 mol %), 5 parts by mass of PRIMAL, TT-65 (Rohm and Haas Co.,
Trade Name) as a thickener, 3 parts by mass of expandable graphite
(expansion start temperature: 220.degree. C., expansion rate: 200
times), 0.5 parts by mass of ammonia water, and 47.5 parts by mass
of water were mixed together to prepare a treatment solution. The
viscosity of the resulting treatments solution was 840 mPas.
[0107] Said treatment solution was then impregnated into said fiber
sheet, in an amount of 40% by mass solid content, after which said
fiber sheet into which said treatment solution was impregnated, was
dried at 100 to 120.degree. C. for 3 minutes in the drying chamber,
with decompression to obtain a precured fiber sheet.
[0108] A nonwoven fiber surface sheet was manufactured by
impregnating a treatment solution into a nonwoven spunbonded
polyester (unit weight 30 g/m.sup.2), said treatment solution
containing 30 parts by mass of sulfomethylated phenol-alkyl
resorcin-formaldehyde precocondensation polymer (55% by mass solid
content), 1 part by mass of carbon black dispersion (30% by mass
solid content) 2 parts by mass of a fluorine group water-oil
repellant agent (20% by mass solid content), 3 parts by mass of a
flame retardant containing phosphorus and nitrogen, and 64 parts by
mass of water, then drying and precuring said nonwoven spunbonded
polyester into which said treatment solution was impregnated in an
amount of 30% by mass solid content, at 130 to 150.degree. C. for 2
minutes in the drying chamber with decompression.
[0109] The resulting precured nonwoven fiber surface sheet was then
put on said fiber sheet, after which the resulting laminated fiber
sheet was hot-pressed at 200.degree. C. for 60 seconds in a
prescribed shape, to obtain a molded laminated fiber sheet, having
excellent shape stability, high rigidity and excellent water-oil
repellency. Further, when said laminated fiber sheet is molded or
finished, fine fibers do not scatter, improving its to workability,
while in a case of a traditional molded laminated sheet, fine glass
fibers stick into the skin of the workers. Further, the fire
resistance of said molded laminated fiber sheet was V-0 according
to UL94 standard, and said molded laminated fiber sheet was useful
as an engine hood silencer. The ventilation resistance of said
molded laminated fiber sheet was 20.5 kPas/m.
EXAMPLE 6
[0110] A fiber sheet (unit weight: 400 g/m2, thickness: 30 mm) was
manufactured by heating a fiber web containing 80% by mass of
hollow polyester fiber (hollow rate: 25%, fiber fineness: 6 dtex,
fiber length: 55 mm), and 20% by mass of low melting point
polyester fiber (softening point: 120, fiber fineness: 6 dtex,
fiber length: 4.5 mm) at 180.degree. C., to melt said low melting
point polyester fiber, wherein the fibers in said fiber sheet were
bound together with said low melting point polyester fiber.
[0111] A treatment solution was prepared by mixing 30 parts by mass
of sulfimethylated phenol-alkylresorcin-formaldehyde
precocondensation polymer (50% by mass solid content), 0.5 parts by
mass of a carbon black dispersion (30% by mass solid content), 2
parts by mass of a fluorine group water-oil repellent agent (20% by
weight solid content), 5 parts by mass of acrylic resin emulsion
(50% by mass solid content), 3 parts by mass of PRIMAL ASE-60 used
in EXAMPLE 3, 5 parts by mass of thermally expandable particles
(capsule type Matsumoto Microsphere F-100: Matsumoto Yushi Seiyaku
Co., Ltd. Trade Name, softening point of shell 135 to 145.degree.
C.), 3 parts by mass of expandable graphite (expansion start
temperature: 200.degree. C., expansion ratio: 150 times), 0.1 parts
by mass of colloidal silica, 0.5 parts by mass of ammonia water
(27% by mass) and 50.9 parts by mass of water. The viscosity of
said treatment solution was 850 mPas. Said treatment solution was
then impregnated into said fiber sheet in an amount of 40% by mass
solid content, and said fiber sheet into which said treatment
solution was impregnated, was then dried at 100 to 110.degree. C.
for 3 minutes in the drying chamber with decompression, to precure
a fiber sheet. The resulting precured fiber sheet was then
hot-pressed at 180.degree. C. for 60 seconds into a prescribed
shape, to expand said thermally expandable particles under the
thickness restrictions, to obtain a molded fiber sheet. The
resulting molded sheet had excellent sound absorbing property, high
rigidity, and excellent water-oil repellency. The fire resistance
of said molded fiber sheet was V-0 according to the UL94 standard,
and said molded fiber sheet was useful as a dash silencer and outer
dash silencer for an automobile. The ventilation resistance of said
molded fiber sheet was 30.3 kPas/m.
EXAMPLE 7
[0112] Sixty parts by mass of phenol-alkylresorcin-formaldehyde
precocondensation polymer (55% by mass solid content), 2 parts by
mass of a fluorine group water-oil repellant agent (15% by mass
solid content), 1 part by mass of a carbon black dispersion (30% by
mass solid content), 0.5 parts by mass of expandable graphite
(expansion start temperature: 200.degree. C., expansion rate: 150
times), 10 parts by mass of methylcellulose (4% by mass water
solution), and 26.5 parts by mass of water were mixed together to
prepare a treatment solution. Said treatment solution was then
impregnated into a needle punched nonwoven polyester fabric sheet
(unit weight 80 g/m.sup.2), in an amount of 25% by mass solid
content. Polyamide powder (200 mesh pass) as a hot-melt adhesive,
having a melting point of 120.degree. C., was scattered on to the
backside of said nonwoven polyester fabric sheet, into which said
treatment solution was impregnated, in an amount of 5 g/m.sup.2,
after which said nonwoven polyester fabric sheet was dried at 130
to 140.degree. C. for 2 minutes in the drying chamber, with said
polyamide powder (hot-melt adhesive) being softened to stick to
said nonwoven polyester fabric sheet, to produce a surface
sheet.
[0113] Said surface sheet was put on said precured fiber sheet,
manufactured in EXAMPLE 6, and the resulting laminated sheet was
then hot-pressed into a prescribed shape at 180 for 60 seconds
under thickness restrictions to expand said thermally expandable
particles, and produce a molded laminated sheet. The resulting
molded laminated sheet had an excellent sound absorbing property,
high rigidity and excellent water-repellency, with a flame
resistance of V-0 according to UL94 standard, so that said molded
laminated sheet was useful as a head lining for an automobile. The
ventilation resistance of said molded laminated sheet was 31.0
kPas/m.
EXAMPLE 8
[0114] A fiber sheet (unit weight: 350 g/m2, thickness: 20 mm)was
manufactured by the needle punching method using a fiber web
containing 60% by mass of polyester fiber (fiber fineness: 1.5 dtx,
fiber length: 45 mm), 10% by mass of low melting point polyester
(softening point: 110.degree. C., fiber fineness: 3 dtex, fiber
length: 54 mm) and 30% by mass of hollow polyester fiber (hollow
ratio: 25%, fiber fineness: 3 dtex, fiber length: 50 mm).
[0115] A treatment solution was prepared by mixing 40 parts by mass
of sulfomethylated phenol-alkylresorcin-formaldehyde
precocondensation polymer (50% by mass solid content), 0.5 parts by
mass of a carbon black dispersion (30% by mass solid content), 3
parts by mass of a fluorine group water-oil repellent agent(15% by
mass solid content), 20 parts by mass of polyvinylalcohol (8% by
mass solid content, saponification degree: 99.5 mol %), 2 parts by
mass of PRIMAL, ASE-60 (Rohm and Hass Co., Trade Name) as a
thicknener, 1 part by mass of PRIMAL, TT-615 (Rohm and Haas Co.,
Trade Name) as a thickener, 0.2 parts by mass of expandable
graphite A (expansion start temperature: 130 to 150.degree. C.,
expansion ratio: 150 times), 7 parts by mass of expandable graphite
B (expansion start temperature: 300 to 320.degree. C., expansion
ratio: 150 times), 0.5 parts by mass of ammonia water (27% by mass)
0.1 parts by mass of 2.6-di-tertiarybutyl-p-cresol group
antioxidant, and 25.7 parts by mass of water. The viscosity of the
resulting treatment solution was 1200 mPas.
[0116] Said treatment solution was impregnated into said fiber
sheet in an amount of 40% by mass solid content and said fiber
sheet, into which said treatment solution was impregnated, was
dried at 100 to 110.degree. C. for 3 minutes in the drying chamber
with decompression, to produce a precured fiber sheet.
[0117] On the other hand, a surface sheet was manufactured by
impregnating a treatment solution into a nonwoven fabric sheet of
meta type aramid fiber (unit weight: 40 g/m.sup.2, fiber fineness:
5 dtex), in an amount of 20% by mass solid content, said treatment
solution containing 40 parts by mass of sulfomethylated
phenol-alkyl resorcin-formaldehyde precocondensation polymer (55%
by mass of solid content), 1 part by mass of a carbon black
dispersion (30% by mass solid), and 2 parts by mass of a fluorine
type water-oil repellent agent (15% by mass), and then precuring
said nonwoven fabric sheet into which said treatment solution was
impregnated at 140 to 150.degree. C., for 2 minutes in the drying
chamber.
[0118] The resulting surface sheet was laminated on to said fiber
sheet, then the resulting laminated sheet was hot-pressed into a
prescribed shape at 210.degree. C., for 60 seconds restricting the
thickness of said laminated sheet, and expanding said expandable
graphite A to produce a molded product. Said molded laminated sheet
has excellent sound absorption property, and high rigidity, as well
as excellent heat resistance and water-oil repellency, the flame
resistance of said molded laminated sheet being V-0 according to
UL94 standard, and is useful as a hood silencer, and engine under
cover silencer of an automobile. The ventilation resistance of said
molded laminated sheet was 10.2 kPas/m.
EXAMPLE 9
[0119] Said treatment solution prepared in EXAMPLE 4 was
impregnated into a felt, wherein recycled fibers were bound with a
synthetic resin (unit weight: 800 g/m.sup.2, thickness: 25 mm) in
an amount of 10% by mass solid content, and then said felt into
which said treatment solution was impregnated, was dried at 100 to
130.degree. C., for 2 minutes in the drying chamber to remove the
water, and then molded at 200 to 230.degree. C. for 3 minutes to
produce a molded fiber sheet. Said molded fiber sheet has excellent
flame resistance and is useful as the floor mat and the like for an
automobile. The ventilation resistance of said molded fiber sheet
was 6.6 kPas/m.
EXAMPLE 10
[0120] A fiber web containing 70% by mass of kenaf fiber (fiber
fineness: 30 dtex, fiber length: 40 mm) and 30% by mass of
polypropylene fiber (softening point: 140.degree. C., fiber
fineness: 1.5 dtex, fiber length: 40 mm) was heated at 180.degree.
C. to melt said polypropylene fiber in said fiber web and bind said
fibers each other with said melted polypropylene fiber, to produce
a fiber sheet (unit weight: 500 g/m.sup.2, thickness: 15 mm).
[0121] A treatment solution was prepared by mixing 85 parts by
weight of an acrylic emulsion (50% by mass solid content), 5 parts
by mass of expandable graphite (expansion start temperature:
300.degree. C., expansion ratio: 150 times) and 10 parts by mass of
a polyvinyl alcohol water solution (10% by mass solid content,
saponification degree: 85 mol %). Said treatment solution was
impregnated into said fiber sheet in an amount of 30% by mass solid
content, and then said fiber sheet into which said treatment
solution was impregnated, was dried at 100 to 130.degree. C. in the
drying chamber to prepare a moldable fiber sheet. Said moldable
fiber sheet was left standing in the drying chamber, at a
temperature of 150 to 180.degree. C. for 5 minutes, to melt said
polypropylene fiber in said fiber sheet, then cold-pressed to
obtain a molded fiber sheet whose-thickness was 5 mm. Said molded
fiber sheet has high rigidity and excellent flame resistance, and
is useful as the doorboard for an automobile. The ventilation
resistance of said molded fiber board was 90.5kPas/m.
EXAMPLE 11
[0122] A fiber sheet (unit weight: 80 g/m.sup.2, thickness: 2 mm)
was manufactured by the needle punching a fiber web containing 95%
by mass of polyester fiber (fiver fineness: 1.5 dtex, fiber length:
36 mm) and 5% by mass of a low melting point polyester fiber
(softening point: 110.degree. C., fiver fineness: 4 dtex, fiber
length: 40 mm).
[0123] A treatment solution was then prepared by mixing 65 parts by
mass of a phenol-alkylresorcin-formaldehyde precocondensation
polymer (50% by mass solid content), 10 parts by mass of a water
soluble epoxy resin (60% by mass solid content), 3 parts by mass of
a an expandable graphite (expansion start temperature: 300.degree.
C., expansion ratio: 150 times), and 22 parts by mass of a
polyvinyl alcohol water solution (5% by mass solid content,
saponification degree: 99.5 mol %). The resulting treatment
solution was then coated on to said fiber sheet by spraying in an
amount of 40% by mass solid content, and then said fiber sheet on
to which said treatment solution was coated, was dried at 150 to
180.degree. C. for 2 minutes in the drying chamber, to obtain a
fiber sheet containing synthetic resin. Said fiber sheet containing
synthetic resin was used as reinforcement for the base of a molded
head lining for an automobile, said base consisting of a hard-type
formed polyurethane, and a surface sheet. Said fiber sheet
containing synthetic resin has high rigidity and excellent flame
resistance.
EXAMPLE 12
[0124] Thirty parts by mass of an acrylic emulsion (50% by mass of
solid content), 15% by mass of a polyvinylalcohol (10% by mass
solid content, saponification degree: 98.5 mol %), 10 parts by mass
of PRIMAL ASE-60 (Rohm and Haas Co., Trade Name), 20 parts by mass
of expandable graphite (expansion start temperature: 300 to
320.degree. C., expansion ratio: 130 times, particle size: 80
mesh), 1 part by mass of ammonia water, and 24 parts by mass of
water were mixed and stirred by effecting an ultrasonic wave
(frequency: 30 kH2) for 5 minutes, to minimize and disperse said
expandable graphite, and prepare a treatment solution. The
viscosity of the resulting treatment solution was 840 mPas. Said
treatment solution was then impregnated into said fiber sheet
manufactured in EXAMPLE 1 (unit weight-50 g/m.sup.2, thickness 15
mm) with said expandable graphite adhering deeply to the inside of
said fiber sheet. It seems that said expandable graphite was
minimized by the effecting ultrasonic wave effect, which improved
dispersability, so that said minimized expandable graphite could
adhere deeply to the inside of said fiber sheet.
EXAMPLE 13
[0125] A fiber web containing 40% by mass of a polyester fiber
(fiber fineness: 5 dtex, fiber length: 25 mm), 20% by mass of low
melting point polyester fiber (softening point: 110.degree. C.,
fiber fineness: 2.5 dtex, fiber length: 20 mm) and 40% by mass of
kenaf fiber (fiber fineness: 40 dtes, fiber length: 30 mm) was
used. Said fiber web was heated to melt said low melting point
polyester fiber and bind said fibers each other with said melted
polyester fiber, and produce a fiber sheet (unit weight: 250
g/m.sup.2, thickness: 30 mm).
[0126] A treatment solution containing 40 parts by mass of a
sulfomethylated phenol-alkylresorcin-formaldehyde precocondensation
polymer (50% by mass solid content), 1 part by mass of a carbon
black dispersion (30% by mass solid content), 2 parts by mass of a
fluorine group water-oil repellent agent (20% by mass solid
content) and 57 parts by mass of water was prepared. Said treatment
solution was then impregnated into said fiber sheet in an amount of
40% by mass solid content, and said fiber sheet into which said
treatment solution was impregnated, was then dried and precured at
140 to 150.degree. C. for 10 minutes in the drying chamber.
Further, said expandable graphite dispersion prepared in EXAMPLE 12
was coated on to said precured fiber sheet by spraying in an amount
of 40 g/m.sup.2 per side, then dried at 140 to 150.degree. C. for 5
minutes to manufacture an expandable graphite coated, precured
fiber sheet. On the other hand, a polyethylene sheet having a
thickness of 20 .mu.m was extruded and laminated on to the back
side of a nonwoven spunbonded fabric (unit weight: 50 g/m.sup.2)
made of a polyester fiber, to produce a nonwoven polyethylene sheet
laminated fiber sheet. Two parts by mass of a phosphorus * nitrogen
group fire retardant was added and mixed into 98 parts by mass of
said treatment solution, and said treatment solution containing
said fire retardant was impregnated into said nonwoven fabric in an
amount of 45% by mass solid content, and said nonwoven fabric in
which said treatment solution was impregnated was dried at 140 to
150.degree. C. for 30 seconds in the drying chamber, to produce a
surface sheet. Said surface sheet was then put on said precured
fiber sheet, after which the resulting laminated fiber sheet was
hot-pressed at 200.degree. C. for 45 seconds, to obtain a molded
laminated sheet. The ventilation resistance of said molded
laminated sheet was 58.3 kPas/m, and flame resistance of said
molded laminated sheet was V-0 according to UL94 standard, so that
said molded laminated sheet has excellent sound absorbing property
and is used as a dashsilencer and outerdash silencer for an
automobile body.
POSSIBILITY OF INDUSTRIAL USE
[0127] Said fiber sheet of the present invention has a high flame
resistance, and is harmless, so that said fiber sheet is useful for
automobile or building interiors, and the like. TABLE-US-00002
TABLE 1 Fire retardancy Stability test of UL94 FMVSS-302 treatment
solutions EXAMPLE 1 V-0 Nonflammability X EXAMPLE 2 V-0
Nonflammability .largecircle. EXAMPLE 3 V-0 Nonflammability
.circleincircle. EXAMPLE 4 Not passed Nonflammability
.circleincircle.
* * * * *