JP2520664B2 - Heat fusible fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Purpose of the Invention [Field of Industrial Application] The present invention relates to a heat-fusible fiber having excellent heat resistance. The heat-fusible fiber can be used as a binder for the base fiber by being mixed with the base fiber and then heated, and the fiber structure bonded and molded using the heat-fusible fiber is a building material, automobile, etc. Can be used in the fields of interior materials, various felts, futons, paddings such as cushions, base fabrics such as carpets, various filters, civil engineering materials and paper diapers, sanitary materials such as sanitary products.

[Conventional technology]

Non-woven fabrics, paddings, rugs, etc. The fiber binders used in the molding of the fiber structures that have been used in the above-mentioned fields include emulsions such as synthetic rubber and acrylic ester polymers, and solvent type binders. Although many have been used, the percentage of using hot-melt type heat-fusible fibers is increasing from the viewpoint of energy saving, pollution prevention, rationalization and the like.

As the heat-fusible fiber used as a fiber binder, those composed of conventional polyester fibers (for example, JP-A-57-66117), those containing polyvinyl alcohol as a main component (for example, JP-A-51-96533), etc. In addition, a fiber having a two-layer structure of a core and a sheath is formed by using two kinds of polyesters whose shapes are not single fibers but different in melting point (for example, JP-A-58-41912), and polypropylene and polyethylene are juxtaposed. Fibers having a composite structure (for example, Japanese Patent Publication No. 52-370)
97), etc., and has been industrially put to practical use.

[Problems to be solved by the invention]

Among products such as non-woven fabrics and cushions formed by using heat-fusible fibers, especially those used in the fields of automobiles, building materials, etc., it is not uncommon to find that the environment temperature in which they are used is high. The fusible fiber is also required to have a considerable heat resistance. The heat resistance in this case has a wide meaning depending on the application, such as that the binding force is retained at high temperature and the restoring force of the molded cushion or the like is retained even at high temperature, but in any case, It is required that the characteristics of the product molded using the heat-fusible fiber at room temperature do not significantly deteriorate even at high temperatures. In this case, the change in the characteristics due to the temperature greatly depends on the type of the heat-fusible fiber. Conventionally studied and industrialized heat-fusible fibers are made from thermoplastic resins such as polyester and polyolefin as described above, so for applications requiring heat resistance, use a high melting point resin that corresponds to the operating temperature. Although it is unavoidable to use such a high melting point resin, a high temperature equal to or higher than the melting point is required both during spinning and when using the obtained fiber as a binder, which is disadvantageous in terms of energy saving. In addition, there is a drawback that a special device such as a high-pressure pot is required, and the base fiber is damaged and deteriorated by heat. There is a method of adding a crosslinking component to improve heat resistance, but spinning is generally difficult with a resin having a crosslinking portion. In particular, melt spinning, which has a high spinning speed and is advantageous from the viewpoint of pollution-free, is difficult, and conversely, if there are few crosslinking components and spinnability is good, heat resistance is insufficient. JP-A-50-20073 is one of such attempts, but the heat resistance cannot be said to be sufficient, and when a fiber other than nylon resin is used as the base fiber mixed with the heat-fusible fiber, I am worried about bonding.

Therefore, the object of the present invention is to perform melt-spinning at a low temperature as a binder for fibers, have good fixability and formability with base fibers, and provide heat fusion properties that enable good heat resistance of the fiber structure after shaping. It's about getting fiber.

(B) Structure of the Invention [Means for Solving Problems] The heat-fusible fiber of the present invention, that is, a polyester resin having a melting point of 60 ° C. to 150 ° C., an epoxy resin having a normal temperature solid, and a carboxylic acid having a melting point of 170 ° C. or more. The heat-fusible fiber characterized by comprising hydrazide solves the above-mentioned problems.

(Polyester resin) The polyester resin in the present invention is used for imparting spinnability during melt spinning, for efficiently promoting the spinning operation, and for improving the texture of the fiber structure obtained by fixing the base fiber. And the melting point is 60 ° C or higher and 150
It is a polyester resin of ℃ or less. A polyester resin having a melting point of less than 60 ° C. has a poor unwinding property during spinning and winding.
On the other hand, if the melting point exceeds 150 ° C., the spinning temperature and the temperature at the time of fusion molding as a binder become high, which is contrary to the purpose.

The component constituting the polyester resin is composed of a saturated dibasic acid and a saturated dihydric alcohol, or a composition obtained by adding some trifunctional or higher functional saturated carboxylic acid and saturated alcohol to them. That is, a saturated polyester resin is preferably used.

Further, a polylactone obtained by ring-opening polymerization of a lactone which is a cyclic polyester can also be preferably used.

(Epoxy compound) The epoxy compound which is solid at room temperature (25 ° C) in the adhesive composition of the present invention is specifically a bisphenol type epoxy resin represented by the following formula- (1) or a formula- (2). Examples thereof include the epoxy novolac resin represented, the glycidyl amine type epoxy compound represented by the formula- (3), and the alicyclic epoxy compound represented by the formula- (4).

Bisphenol type epoxy resin However, in the formula- (1), A: hydrogen or an alkyl group Y: represents a halogen atom, hydrogen, etc.

Epoxy novolac resin Glycidylamine type epoxy compound (R in formulas (2) and (3): alkyl, araalkyl, aromatic hydrocarbon, etc.) Alicyclic epoxy compound (R ': hydrocarbon group containing alkyl group, ester group, ether group, oxirane group, etc. l: natural number, m and n: an integer of 0 or more) The epoxy compound preferable for the present invention is 1 in one molecule.
A resin with more than one oxirane group and a melting point of 50 ° C or higher 16
It is below 0 ° C.

Those having a melting point of less than 50 ° C. are difficult to spin, and have tackiness when formed into fibers, which may cause problems in blending and crimping. Also, 160
Those having a melting point exceeding 0 ° C. may have high spinning temperatures and high heating temperatures when they are fixed as binders, and the effects intended by the present invention may be difficult to achieve.

(Carboxylic Acid Hydrazide) The carboxylic acid hydrazide having a melting point of 170 ° C. or higher in the heat-fusible fiber of the present invention serves as a curing agent for an epoxy compound, and is obtained by a reaction between an organic carboxylic acid and hydrazide. To be It is represented by the structure of the following formula- (5).

RCONHNH ₂ ) _n (5) (R: alkyl, araalkyl, aromatic hydrocarbon, etc. n: natural number) The carboxylic acid dihydrazide of the present invention does not react with an epoxy compound during melt mixing and spinning performed at a low temperature.
It cures by reacting at a temperature of around 0 ° C.

Preferred carboxylic acid hydrazides include dihydrazides of dibasic acids from the viewpoint of effectively improving the heat resistance of the target fiber structure by effectively curing the epoxy compound, and specific examples thereof include: There are dihydrazides of saturated or unsaturated aliphatic dibasic acids such as adipic acid dihydrazide, sebacic acid dihydrazide, and dodecanedioic acid dihydrazide, and aromatic dibasic acid dihydrazides such as isophthalic acid dihydrazide.

The carboxylic acid hydrazide having a melting point of less than 170 ° C.
It is not used in the present invention because it produces scale in the extruder during spinning and makes the molten state and fineness of the fiber unstable.

Since the particle size of the carboxylic acid dihydrazide affects the spinnability, it is preferable for the present invention that the particle size be as small as possible, for example, several μm or less.

(Blending ratio) The blending amount of the polyester resin in the heat-fusible fiber of the present invention is 3: 7 to 9: 1 (weight ratio) with respect to the thermosetting component composed of the epoxy compound and carboxylic acid hydrazide. Is desirable. That is, if the amounts of polyester resin, epoxy compound and carboxylic acid hydrazide are A, B and C, A is A + B
30 to 90% by weight of + C, that is, It is desirable that

When the proportion of the polyester resin is higher than the above range, the heat resistance may not be improved to an effective degree even after the post-curing operation, and conversely, when it is low, the spinnability is poor and the texture of the obtained fiber structure is deteriorated. May cause

Further, the compounding amount of carboxylic acid hydrazide is preferably set to the following ratio. That is, the amount of the carboxylic acid hydrazide compound in the composition is preferably blended so that the ratio of the acid hydrazide group is 0.45 to 2.0 with respect to one oxirane group in the epoxy compound. If the number of acid hydrazide groups is less than 0.45 per one oxirane group, the epoxy compound may not be sufficiently cured and good heat resistance may not be obtained. On the other hand, when the number exceeds 2.0, the amount of carboxylic acid hydrazide dispersed in the solid state during spinning increases,
It is difficult to obtain fibers having a uniform composition, and problems such as easy clogging of the spinneret are likely to occur.

(Other Additives) The heat-fusible fiber of the present invention may be blended with various compounds other than the above-mentioned components. For example, a latent curing accelerator for accelerating and improving the curing rate, various resins for improving the characteristics, and further components that are blended with ordinary heat-fusible fibers, that is, organic and inorganic feelers, viscosity modifiers, It may be a mixture of flame retardants, pigments, dyes, stabilizers and the like.

Examples of latent curing accelerators include high-melting point tertiary amine compounds, high-melting point imidazole compounds, phosphine compounds, alkyl metal compounds, guanidine compounds, supercoordinating silicate compounds, and group 5B element compounds of the periodic table. Ionic addition compounds, sulfonium compounds, iodonium compounds and the like can be mentioned. Such a latent curing accelerator shows almost no curing-accelerating action at a low temperature with respect to the reaction between the above-mentioned carboxylic acid hydrazide which is a curing agent and an epoxy compound, but in a high temperature state necessary for curing. It can be said that it exhibits a remarkable effect that it has a characteristic of rapidly exhibiting a hardening promoting action, and is preferable as an additive in the practice of the present invention.

In addition, for the purpose of improving workability during melt mixing, improving spinnability, improving the texture of molded products, and reducing raw material costs, polyolefin, polyamide, polyvinyl chloride, polyvinylidene chloride, poly (ethylene-vinyl acetate), Various rubbers such as polyethylene alkyl acrylate, polyurethane, polybutadiene and polyisoprene, and resins such as epoxy resin, phenol resin, urea resin and melamine resin are added. Various organic and inorganic filler viscosity modifiers, flame retardants, pigments, dyes, stabilizers, etc. can also be applied.

(Fiber manufacturing method and application method) The heat-fusible fiber of the present invention uses a heatable reactor equipped with a stirrer, a single-screw or twin-screw extruder, etc. for the blending components, and the epoxy resin causes a curing reaction substantially. At a temperature below a certain temperature, melted, mixed, pelletized and fiberized according to a usual melt spinning method, but the spinning temperature is a temperature below which the epoxy resin and the carboxylic acid hydrazide do not substantially react,
It is carried out at a temperature above the temperature at which the entire composition becomes fluid, that is, generally at 60 ° C to 150 ° C.

The fiber of the present invention can be used not only as a single fiber having a uniform composition in the cross-sectional direction but also as a composite fiber using the composition constituting the fiber of the present invention as a part of the constitution. The core / sheath type composite fiber in which other fiber having a higher melting point than the fiber of (1) is used as the core, and the composition constituting the fiber of the present invention is superposed on the core / sheath type composite fiber, and the fiber of the present invention. Side-by-Side juxtaposed with other fibers
It can also be used in the form of type composite fibers. In the case of a single fiber, a yarn having a diameter of 1 to 30 denier, preferably 2 to 15 denier can be used. Further, the ratio of the fiber of the present invention in the composite fiber is in the range of 20 to 80%. The spun fiber may be applied with a spinning oil agent, stretched, etc., if necessary.
After being crimped, it is cut into a staple shape.
The staple length is 10 to 200 mm, preferably 30 to 100 mm. The staples thus obtained are mixed and spun with a base fiber and a card by an ordinary method, and then superposed to have an appropriate thickness. This is heat-treated at a temperature of 130 ° C. to 200 ° C., preferably 140 ° C. to 180 ° C. to melt-bond the fibers and crosslink the epoxy resin to obtain a heat-resistant non-woven fabric or a molded product such as a cushion or an interior material. be able to. By slightly applying pressure at the time of joining, the bond strength is further increased.

(Function) The heat-fusible fiber of the present invention has a melting point of 60 to 150 ° C. and a normal temperature solid epoxy compound having a thermosetting performance of a polyester resin and a melting point of 170 ° C. or more, which is composed of a carboxylic acid hydrazide. Carboxylic acid hydrazide acts as a latent curing agent for epoxy compounds and cures it. It maintains stable melt spinnability for a long time, and stable spinnability and thermal fusion make it possible to form a fiber structure with good heat resistance. Enables manufacturing.

In addition, carboxylic acid hydrazides with a melting point of 170 ° C or higher do not exert their effect during melt spinning at low temperatures, and react with the epoxy compound at the heat fusion temperature during the production of the fiber structure at around 150 ° C to cure them. Show. Therefore, the heat-fusible fiber of the present invention can be stably melt-spun and can be stored at room temperature, for example, melt-spun in a temperature range of 100 ° C to 150 ° C. Further, for example, it can be cured at a temperature of around 150 ° C., and a fibrous structure having good heat resistance at a high temperature can be produced.
Thus, by the action of carboxylic acid hydrazide as a latent curing agent, it has an excellent action of stability at room temperature, good melt spinning at an appropriate temperature, and production of a fiber structure having good heat resistance. is there.

〔Example〕

Hereinafter, examples of the present invention will be described together with comparative examples.

Example 1 Bisphenol A-type epoxy resin Epicoat 1007 (produced by Yuka Shell Epoxy Co., melting point 128 ° C. epoxy equivalent 1750-2
200 g / equivalent) 100 parts by weight and terephthalic acid / isophthalic acid /
60 parts by weight of copolymerized polyester (melting point 90-110 ° C, Viccard softening point 50 ° C) consisting of adipic acid / butanediol / neopentyl glycol = 50/25/25/50/56 (molar ratio) and terephthalic acid / isophthalate Copolymerized polyester consisting of acid / ethylene glycol / neopentyl glycol = 50/50/50/50 (molar ratio) 45 parts by weight (melting point 120 ° C.), ethylene consisting of acetic acid / ethylene = 20/80 (weight ratio) 15 parts by weight of vinyl acetate copolymer resin (Vicat softening point 59 ° C.) and 5 parts by weight of isophthalic acid dihydrazide (melting point 212 ° C., molecular weight 194) crushed to an average particle size of 2 μm are mixed in a twin-screw extruder (cylinder temperature 95 ° C.). ， Outlet resin temperature 120 to 125
℃), after forming a 4 mmφ straddle, it was pelletized using a pelletizer. Pellets with a pore size of 0.1 at a temperature of 125 ° C
Melt-spinning was performed from a nozzle having 0 mm and the number of holes was 3 to obtain a filament of 7d. The strength after stretching this filament three times
It was 3 g / d. After the drawn filaments are cut into staples with a length of 35 mm, they are mixed at a ratio of 20/80 (weight ratio) to 50 cm long, 13d polyester fibers, and then made into a nonwoven fabric with a density of 0.025 g / cm ³ by a card and placed in a hot air oven. At 150 ° C. for 2 minutes, the fibers were fused together to form a 50 mm thick cushion-like sheet.

This cushion was sandwiched between the presses and compressed to a thickness of 25 mm, left in an atmosphere at 110 ° C for 22 hours and then removed.
When the thickness was measured after standing for 30 minutes at room temperature, the thickness recovered to 42.5 mm. In this case, the compression residual strain rate C according to JIS K6401 was C = 15.0%.

Example 2 Bisphenol A type epoxy resin Epicoat 1009 (produced by Yuka Shell Epoxy Co., Ltd., melting point 148 ° C., epoxy equivalent 240)
0-3300 g / equivalent) and ε-caprolactone obtained by ring-opening polymerization of Placcel H-4 (manufactured by Daicel Chemical Industries Ltd., number average molecular weight 40,000, melting point 60 ° C.) 80:20
(Weight ratio) and mixed and reacted for 3 hours at 160 ° C. to obtain a modified epoxy resin. 100 parts by weight of this modified epoxy resin, 20 parts by weight of polyurethane elastomer Pandex F5201 (Dainippon Ink, Vicat softening point 100 ° C), copolyester resin PES140 (Toa Gosei Chemical Industry Co., Ltd., melting point)
80 parts by weight (135 to 145 ° C.) and 5 parts by weight of dodecanedioic acid dihydrazide (melting point 185 ° C., molecular weight 258) were mixed in the same manner as in Example 1 and further spun. However, the temperature of the twin-screw extruder was 120 ° C for the cylinder temperature, 140-145 ° C for the outlet resin temperature, and 140 ° C for the spinning temperature. When a cushion sheet was prepared in the same manner as in Example 1 and the compressive residual strain rate was measured, C = 14.0%.

Example 3 68 parts by weight of bisphenol A type epoxy resin Epicoat 1002 (manufactured by Yuka Shell Epoxy, melting point 83 ° C., epoxy equivalent 650 g / equivalent) and isophthalic acid dihydrazide (melting point 212 ° C.)
Molecular weight 194) 15 parts by weight, copolyester resin PES110
Toa Gosei Chemical Industry Co., Ltd., melting point 105-115 ° C) 70 parts by weight,
Polyurethane elastomer Desmocol 406 (Sumitomo Bayer Urethane Co., Ltd., Vicat softening point 31 ° C) 25 parts by weight, vinylidene chloride copolymer resin UL-321 (Toa Gosei Chemical Co., Ltd., Vicat softening point 60 ° C) 15 parts by weight were mixed by an extruder and pelletized by the same method as in Example 1. Coated polyester resin PES170 (manufactured by Toagosei Chemical Industry Co., Ltd., melting point 170)
(° C) as the core component, using a core-sheath type composite spinneret, spinning was performed at a pellet-side spinning temperature of 125 ° C, a copolyester PES170-side spinning temperature of 200 ° C, and a spinneret temperature of 170 ° C. The obtained composite fiber had a composite ratio of 50:50 and a fineness of 8d. This fiber was cut into 6 cm, and this was mixed with polyester fiber having a fiber length of 5 cm and a fineness of 10 d at a weight ratio of 40:60 to make a nonwoven fabric with a density of 0.03 g / cm ³ by a card, and heat-treated in a hot air oven at 150 ° C for 3 minutes to 60 mm. A thick cushion-like sheet was formed. The compressive residual strain rate of the obtained cushion was 16.5%.

Comparative Example 1 When a copolymerized polyester resin having a melting point of 50 ° C. was used in place of the copolymerized polyester used in Example 1, and spinning was carried out in the same manner as in Example 1 except that the tack remained on the yarn and unwound. The filament could not be obtained due to poor property.

Comparative Example 2 When a copolyester resin having a melting point of 165 ° C. was used instead of the two types of copolyester used in Example 1, an extrusion temperature (exit temperature) of 170 ° C. or higher was required.

Comparative Example 3 Instead of the drawn filament obtained in Example 1, commercially available polyester-based heat-bonding binder fiber (melting point) was used.
A cushion-like sheet was formed by mixing and spinning in the same manner as in Example 1 using 115 ° C., fineness 3d, length 70 mm). When the compression residual strain rate was measured by the same method as in Example 1, it was C = 50%.

Comparative Example 4 Spinning was performed under exactly the same conditions except that succinic acid dihydrazide (melting point 163 ° C., molecular weight 146) was used in place of isophthalic acid hydrazide in Example 1, but the fineness changed with time and yarn breakage occurred. It was impossible to continue spinning for more than an hour.

Comparative Example 5 In Example 1, vinylidene chloride copolymer resin UL-321 (manufactured by Toagosei Kagaku Kogyo Co., Ltd., Vicat softening point 60 ° C., melting point 90 ° C.) 105 was used instead of the two types of copolymerized polyester.
Spinning was carried out in the same manner as in Example 1 using parts by weight, but the strength of the filament was low and it was impossible to continue spinning.

(C) Effect of the Invention As described above, the heat-fusible fiber according to the present invention can be produced by the melt spinning method at a low temperature, and the obtained heat-fusible fiber is used for a nonwoven fabric, a cushion, etc. It is also possible to perform molding at a low temperature. Furthermore, the heat resistance of the structure obtained by molding is extremely good, and it is most suitable for the fiber structure for automobiles and building materials, which requires heat resistance, and contributes greatly to those industries. is there.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location D04H 1/54 D04H 1/54 H J (72) Inventor Hiroyuki Kondo Funami Town, Minato-ku, Aichi Prefecture 1-1, Toagosei Chemical Industry Co., Ltd. (72) Inventor Yoshiaki Fujimoto 1-1-1, Funami-cho, Minato-ku, Nagoya, Aichi Prefecture In-laboratory, Toagosei Chemical Industry Co., Ltd. (72) Takashi Nakatani Nagoya, Aichi Prefecture 1-1, Funami-cho, Minato-ku, Toagosei Chemical Industry Co., Ltd. (72) Inventor Toshio Okuyama 1-1-1, Funami-cho, Minato-ku, Nagoya City, Aichi Prefecture Toagosei Chemical Industry Co., Ltd.

Claims (1)

(57) [Claims] 1. A polyester resin having a melting point of 60 ° C. to 150 ° C.,
A heat-fusible fiber comprising an epoxy compound at room temperature and a carboxylic acid hydrazide having a melting point of 170 ° C. or higher.