Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
  • D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
  • D01F8/06—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyolefin as constituent
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/07—Addition of substances to the spinning solution or to the melt for making fire- or flame-proof filaments

Definitions

• This invention relates to fire retardant composite fibres and a process for producing them. More particularly it relates to polyolefin composite fibres comprising two kinds of polyolefin polymers having - different melting points and having the same or different fire retardants in the two components.
• Polyolefin composite fibres have superior heat adhesive properties and also physical and chemical properties and further are of light weight and cheap; hence they have been used as a fibre material for non-woven fabrics in various applications fields. For example, they are suitable as a material for thin products such as fabric bases, hygienic materials, napkins, paper diapers, and for thick products such as quilting goods, various felts, filters, fibre-shaped products, materials for public works, etc. In general, fire retardant properties have been used indoors for fibre materials.. As a process for making polyolefin fibres fire retardant, there is first a process of adding a fire retardant to raw material polymers, followed by spinning.
• the present inventors have made various studies on such problems and found that when the higher melting and lower melting components of composite fibres respectively contain a fire retardant having a decomposition temperature higher than the melting points of the respective components by 100°C or more and also having a particle size of 62 microns or less, it is possible to produce superior fire retardant and heat adhesive composite fibres of a small denier having a relatively large amount of the fire retardant blended also with the lower melting component, with a good spinnability.
• One aspect of the present invention resides in:
• composite fibres are characterized in that a fire retardant having a decomposition temperature higher than the melting points of the respective components by 100°C or more and also having a particle size of 62 microns or less, is contained in the respective components in an amount of 3 to 15% by weight, and the total of the respective amounts of the fire retardant contained in .
• the whole of the composite fibres is 5 to 10% by weight.
• Another aspect of the present invention resides in:
• Composite fibres of the present invention also have various application fields, and it is particularly preferable for them to be a side by side or a sheath and core type, so that the lower melting component can have a percentage fibre-cross-sectional circumference of 50% or higher, thereby to provide the composite fibres provided with heat adhesive properites by way of the lower melting component.
• the composite ratio (higher melting component: lower melting component) is preferably in the range of 5:5 to 3:7 in view of the thickness of the lower melting component in the fibre section.
• the higher melting component is preferably polypropylene or copolymers composed mainly of propylene having a fibre formability.
• the lower melting component is preferably polyethylene, ethylene-vinyl acetate copolymers, abbreviated to EVA, having a vinyl acetate content of, eg 1 to 10% by weight, their saponified products., blends of polyethylene with EVA or saponified EVA.
• the respective contents of the fire retardant in the high melting component and the lower melting component of the composite fibres are suitably in the range of 3 to 15% by weight, and the total content of the fire retardant in the whole of the composite fibres is suitably in the range of 5 to 10% by weight. If the contents of the fire retardant are lower than the above ranges, the fire retardant effectiveness is small, and if.the contents exceed the above ranges, the spinnability of the fibres becomes inferor thereby to make their production difficult and degrade their quality.
• the fire retardant used in the present invention may be suitably selected from known materials.
• organic halogen compounds are preferable, and concretely preferable examples thereof are decabromodiphenyl oxide (decomposition temperature: 350°C; the temperatures inside the following parentheses likewise indicating decomposition temperature), perchloropentacyclododecane (650°C), ethylenediamine dihydrobromide (355°C), hexabromobenzene (340°C), 2,2-bis[4-(2,3-dibromo- propoxy)-3,5-dibromophenyl]propane (270°C), tris(2,3-dibromopropyl)phosphate (260°C), bis[3,5-dibrom-4-di- bromopropyloxyphenyl]sulfone (280°C), etc.
• fire retardants are also preferably used in admixture with Sb 2 0 3 in a ratio of retardant to Sb 2 0 3 in a ratio of 1.5:1 to 3:1.
• the fire retardants used in the present invention have a particle size of 62 microns or less. If the fire retardants contain particles larger than 62 microns, this causes reduction in their productivity or quality, due to, eg, clogging of spinning nozzle, fibre breakage at the time of stretching, forming of rough surface on fibres which lowers their heat adhesive properties.
• the fire retardants having a particle size of 62 microns or less may be obtained by grading commercially available fire retardants by way of a known method such as a precipitation method, cyclone method, etc, and as a simpler method, by grading them through sieves indicated in JIS Z 8801 (nominal diameter 62 or 53 microns).
• the fire retardant composite fibres of the present invention may be produced according to a conventional melt-composite-spinning process and the apparatus employed may also be a conventional apparatus.
• a powdery raw material polymer having a fire retardant mixed is melted and extruded by a melt-extruder and the resulting melt is passed through a temperature- controlled heating zone to heat it to a definite temperature (hereinafter often referred to as spinning temperature).
• the melting and temperature adjustment of the polymer are carried out in separate passages for each of the commosite components, and the respective composite components each having a definite temperature are fed in a composite ratio into spinning nozzles through the holes of which they are composite-spun.
• a fire retardant having a decomposition temperature higher than the melting piont of the components by 100°C or more, preferably higher than the spinning temeratures by 40°C or more, thereby to prevent the decomposition and consumption of the fire retardant at the time of spinning.
• Unstretched filaments obtained by the composite spinning are stretched in an appropriately chosen ratio depending on application fields. Usually the stretching is carried out very often in a stretch ratio of 4 or more.
• the stretching temperature temperatures in the range of from the softening point of the lower melting component up to a temperature lower than the melting point by 10°C may be employed, but the effect of the extent of the stretching temperature upon the fire retardant properties is little.
• the process of the present invention it is possible to produce composite fibers containing a large amount of a fire retardant and having a small fineness, with small frequencies of fiber breakage due to clogging of spinning nozzles and exchange of spinning die, in a stabilized manner and over an extremely long term.
• the fire retardant composite fibers of the present invention are not only provided with fire retardant properties, but also, in spite of a large amount of fire retardant contained therein, have a smooth surface and superior heat adhesive properties.
• Sb 2 0 3 is regarded as an additive other than fire retardants.
• JIS method method according to JIS L1091, Al (45° microburner).
• a polypropylene (PP) having a MFR of 4 (according to JIS K7210, condition 14) and a melting point of 160°C were used.
• a fire retardant (decabromodiphenyl oxide) having passed through a definite sieve as indicated in the Table shown later, in definite amounts relative to the PE and PP, respectively, as indicated in the Table, and Sb 2 0 3 in 1 / 2 of the respective amounts of the fire retardant were added to the PE and PP, separately.
• Composite spinning was then carried out in a composite ratio of 1:1, at a spinning temperature on the PE side of 230°C and at that on the PP side of 300°C to obtain unstretched side-by-side composite filaments having percentages fiber-cross-sectional circumference of the._PE component of 78 to 85%. These filaments were stretched to 4 times the original lengths and cut to obtain staple fibers of 18d/f (deniers per filament) x 64 mm, which were then carded to prepare a web of 2 50 g /m 2 .
• This web was subjected to heat treatment at 140°C for 5 minutes to obtain a sheet of non-woven fabric of 15 mm thick, partially adhered on the PE side.
• This sheet was allowed to cool in a desicator for 3 - 4 hours, followed by carrying out combustion test according to the above JIS method to measure flame-remaining time (seconds) and carbonized area (cm 2 ). Further, the same sheet of non-woven fabric was subjected to the above combustion test according to the match method. The results of blending of fire retardants, spinning test and combustion tests are shown in the Table.
• Example 1 and 2 are compared with Comparative examples 1 and 2,and Example 3 is compared with Comparative examples 3 and 4, even if the contents of a fire retardant in the whole of the fibers are the same, if the fire retardant is contained only in an amount less than 3% inside one of the composite components, the fire retardant effectiveness is inferior, and this is remarkable particularly in the evaluation according to the match method. Further, if the fire retardant is contained in an amount exceeding 15% inside one of the composite components, the spinning nozzle life becomes shorter and also the frequency of fiber breakage increases; hence such amount is also undesirable.
• an ethylene-vinyl acetate copolymer (EVA) having a melting point of 110°C, a content of vinyl acetate component of 5% and a MFR of 25 (according to JIS K7210, condition 2) was used, and as a higher melting component, a polypropylene (PP) having a MFR of 4 was used.
• EVA ethylene-vinyl acetate copolymer
• PP polypropylene
• a blend of perchloropentacyclododecane as a fire retardant to Sb 2 0 3 in a ratio of 2:1 was added in a definite amount to the PP and a blend of bis(3,5-dibrom -4-dibromopropyloxyphenyl)sulfone to Sb 2 0 3 in a ratio of 1.5:1 was added in a definite amount to the EVA, as indicated in the Table.
• Composite spinning was then carried out in a composite ratio of 1:1 at a temperature of the lower melting component of 200°C and at that of the higher melting component of 280°C to obtain unstretched filaments which were then stretched to 4 times the original length and cut to prepare staple fibers (6d/f ⁇ 64 mm) of sheath and core type composite fibers having a percentage fiber-cross-sectional circumference of the lower melting component of 100%, from which a sheet of non-woven fabric was prepared, followed by subjecting it to a combustion test as in Examples 1 and 2 to evaluate its fire retardant properties. The results are shown in the Table.
• a polyethylene (MFR: 10) (PE) was used and as a higher melting component, a polypropylene (MFR: 8) (PP) was used-Blends of tris(2,3-dibromopropyl)phosphate, 1,2-dibrom -3-chloropropane or pentadibromomonochloro- cyclohexane as a fire retardant, each in a definite amount, to Sb 2 0 3 in an amount in a ratio of the fire retardant to Sb 2 O 3 of 3:1 were respectively added in a definite amount to PE, while a blend of ethylenediamine dihydrobromide to Sb 2 0 3 in a ratio of 2:1 was added in a definite amount to PP, as indicated in the Table.
• Composite spinning was then carried out at a temperature on the lower melting component side of 210°C and at that on the higher melting component side of 300°C, in a composite ratio of l:l to obtain unstretched filaments which were then stretched to 4 times the original length and cut to obtain staple fibers of side by side composite fibers (3d/f x64 mm) having a percentage fiber-cross-sectional circumference of the lower melting component of 49 -50%.
• a sheet of non-woven fabric was prepared from the staple fibers as in Examples 1 and 2 to evaluate the fire retardant properties. The results are shown in the Table.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Multicomponent Fibers (AREA)
• Nonwoven Fabrics (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=12545555

Family Applications (1)

Country Status (7)

Cited By (7)

Families Citing this family (1)

Citations (1)

• 1982
  • 1982-03-12 JP JP57039167A patent/JPS58156019A/ja active Pending
• 1983
  • 1983-02-09 EP EP83300640A patent/EP0089113B1/de not_active Expired
  • 1983-02-09 DE DE8383300640T patent/DE3371545D1/de not_active Expired
  • 1983-02-25 DK DK089583A patent/DK155803C/da not_active IP Right Cessation
  • 1983-03-09 FI FI830779A patent/FI75875C/fi not_active IP Right Cessation
  • 1983-03-11 KR KR1019830000980A patent/KR880000376B1/ko not_active IP Right Cessation
  • 1983-03-11 AU AU12424/83A patent/AU555246B2/en not_active Ceased

Patent Citations (1)

Non-Patent Citations (3)

Also Published As

Similar Documents

Legal Events