JP3254826B2 - Polyester nonwoven fabric and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester nonwoven fabric and a method for producing the same. More specifically, the present invention has a moderate strength useful for clothing, gas or liquid filtration materials, oil / water separation materials, and the like. The present invention relates to a method for producing a polyester nonwoven fabric in which a polyester nonwoven fabric and a polyester copolymer are produced without a drying step.

[0002]

2. Description of the Related Art A polyester nonwoven fabric and a method for producing the same are conventionally known as a method for obtaining a nonwoven fabric by discharging a molten polymer from an orifice using an extruder. For example, Japanese Patent Application Laid-Open No. 55-142775 discloses a method for producing a polyester ultrafine fiber web.

[0003]

However, the conventional polyester is easily hydrolyzed, and when hydrolyzed, the polyester undergoes molecular cleavage. For this reason, the change in the intrinsic viscosity before spinning and the intrinsic viscosity of the nonwoven fabric was large, the change in molecular weight and the change in melt viscosity were large, and the nonwoven fabric manufacturing method was unstable.
To stabilize the nonwoven fabric manufacturing method, a drying step was essential. The hydrolyzed polyester nonwoven fabric had a reduced fiber strength, and a nonwoven fabric having stable nonwoven fabric performance and good texture could not be obtained.

An object of the present invention is to solve the problems described above, and the present invention provides a polyester nonwoven fabric useful for a filter material, an oil-water separator, a clean room garment, a base fabric for artificial leather, and a method for producing the same. What you want to do.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a polyester copolymer comprising a specific alkyl-substituted 1,3-propanediol having 2 or more carbon atoms of 2 or more is used. The present inventors have found that the polyester nonwoven fabric and the method for producing the same exhibit excellent effects on the above-mentioned problems, and have completed the present invention. That is, the gist of the present invention is: 1: terephthalic acid, ethylene glycol and 2,2-
A polyester nonwoven fabric characterized by using a polyester copolymer comprising an alkyl-substituted-1,3-propanediol having 2 or more carbon atoms, and 2: an alkyl-substituted 2,2-carbon atom having 2 or more carbon atoms in a diol component. The molar ratio of 1,3-propanediol is 3 to 50 mol%, and the alkyl-substituted 1,3- having 2,2-carbon atoms of 2 or more.
The alkyl of propanediol is ethyl group, propyl group,
The polyester nonwoven fabric as described above, comprising a butyl group and a pentyl group, and 3: terephthalic acid, ethylene glycol and 2,2-
An alkyl-substituted-1,3-propanediol having 2 or more carbon atoms is polycondensed with a catalyst to have an intrinsic viscosity of 0.2 to 1.0.
Polyester copolymer of, obtained by heating and melting the polyester copolymer in an extruder without drying, using a single component type, parallel type, sheath core type, multi-segment type or sea-island type die, regular method, This is a method of producing the above-mentioned polyester nonwoven fabric by spinning using a melt blow method or a spun bond method, and using an adhesive, self-heating melting or papermaking method.

[0006] The diol component of the polyester copolymer of the present invention is a specific diol component, and includes ethylene glycol and alkyl-substituted-1,2,2- or more having 2 or more carbon atoms.
Consists of 3-propanediol. This specific diol is
In the diol component, the molar ratio of 2,2-alkyl-substituted-1,3-propanediol having 2 or more carbon atoms is preferably 3 to 50 mol%. That is, when the molar ratio of the alkyl-substituted-1,3-propanediol having 2,2-carbon number of 2 or more is less than 3 mol%, the thinning effect for sufficiently lowering the melt viscosity is poor, the spinning is not stable, and the fibers in the web Are easily scattered, making collection difficult. On the other hand, if the molar ratio exceeds 40 mol%, the fiber strength becomes low, and the dimensional stability under heat is lost. 2,2-carbon number 2
As the above alkyl-substituted-1,3-propanediol, those whose alkyl is selected from the group consisting of an ethyl group, a propyl group, a butyl group and a pentyl group are preferable, and specifically, 2,2-diethyl-1 , 3-propanediol (hereinafter referred to as DMP), 2-butyl-2-ethyl-1,3-propanediol (hereinafter referred to as DMH), 2-pentyl-2-propyl-1,3-propanediol (hereinafter referred to as DMN) .) Can be exemplified. These can be used alone or in any combination depending on the purpose of use.

[0007] The polyester copolymer in the present invention comprises terephthalic acid, ethylene glycol and 2,2.
2- Other components of alkyl-substituted-1,3-propanediol having 2 or more carbon atoms, for example, isophthalic acid, 1,2-bis (4-carbophenoxy) ethane, 2,6 -Naphthalene dicarboxylic acid, aromatic polycarboxylic acids such as trimellitic acid and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, oxalic acid, propylene glycol, butylene glycol, bisphenol A, neopentyl glycol, polyethylene glycol, polypropylene glycol, Glycerin,
A polyol such as pentaerythritol may be contained as a copolymer component.

As the polymerization method of the polyester copolymer in the present invention, various ordinary methods can be used. For example, a method of performing a transesterification reaction of a dimethyl ester of a dicarboxylic acid and a diol to distill methanol and then performing a polycondensation method under a reduced pressure and a high vacuum gradually, or an esterification reaction of a dicarboxylic acid and a diol is formed. After distilling water, gradually depressurizing and under high vacuum, performing polycondensation, or when using dimethyl ester of dicarboxylic acid and dicarboxylic acid in combination as raw materials, perform transesterification of dimethyl ester of dicarboxylic acid and diol Further, there is a method of performing an esterification reaction by adding a dicarboxylic acid and then performing polycondensation under a high vacuum. As a transesterification catalyst, manganese acetate, calcium acetate, zinc acetate, etc., and as a polycondensation catalyst, antimony trioxide, germanium oxide,
Known materials such as dibutyltin oxide and titanium tetrabutoxide can be used.

Phosphorus compounds such as trimethyl phosphate and triphenyl phosphate as stabilizers, Irganox 101
A hindered phenolic compound such as 0 may be used. It may also contain a matting agent and other additives. Various conditions such as a polymerization method, a catalyst, and a stabilizer are not limited to the above examples.

The intrinsic viscosity of the polyester copolymer in the present invention is preferably from 0.2 to 1.0, more preferably from 0.5 to 1.0.
-0.8, particularly preferably 0.55-0.75. If the intrinsic viscosity is more than 0.8, the melt viscosity becomes too high, so that the orifice is liable to be stained. On the other hand, if the intrinsic viscosity is less than 0.5, sufficient fiber strength cannot be obtained.

The polyester copolymer of the present invention surprisingly has no decrease in intrinsic viscosity due to hydrolysis when melted at 300 ° C. even if it absorbs moisture at 3000 ppm. No need to dry until. Therefore, spinning can be performed even when the water content of the polyester copolymer in the present invention is 3000 ppm or less, preferably 2000 ppm or less. However, it is stored for a long time in the air and 3000pp due to condensation etc.
If it exceeds m, the hydrolysis resistance may suddenly decrease.

The fiber diameter of the polyester used for the nonwoven fabric of the present invention may be a thick denyl, a fine denyl, or an ultrafine fiber of 10 μ or less. A high strength nonwoven fabric can be obtained. The smaller the average fiber diameter, the better the filter performance, dust absorption, liquid absorption, and heat insulation.

The apparatus for producing a polyester nonwoven fabric for carrying out the method of the present invention does not require any special improvement, and can be carried out by using a conventionally used general one. Further, it is preferable that the melting temperature of the polyester copolymer and the temperature of the spinneret are lower as long as the purpose is satisfied.
Further, the polyester nonwoven fabric obtained by the method of the present invention may be used alone, or may be used in a state of being laminated or laminated and integrated with another nonwoven fabric, woven or knitted material or a mesh-like material. Various spinning methods such as a single-component type, a side-by-side type, a sheath-core type, a multi-split type, and a sea-island type can be applied to the polyester spinning method of the present invention. For example, there are a regular method, a melt blow method, a spun bond method and the like, and a non-woven fabric can be formed by an adhesive, self-heating melting or papermaking method. In particular, the melt-blow spinning method is preferable because an ultrafine nonwoven fabric can be easily produced. The polyester nonwoven fabric of the present invention may be composed of long fibers or short fibers, but long fibers do not have a cutting step, and can be easily manufactured by melt-blowing or spunbonding by direct connection. The web may be formed by needle locking or a combination thereof.

[0014]

EFFECT OF THE INVENTION Conventional polyester nonwoven fabrics are liable to be hydrolyzed by the raw material polyester, and the nonwoven fabric manufacturing method in which the raw materials are not dried causes hydrolysis and molecular cutting. On the other hand, since the polyester nonwoven fabric manufacturing method of the present invention uses a polyester using a specific diol having a long side chain, the change in the intrinsic viscosity before spinning and the intrinsic viscosity of the nonwoven fabric is small, and it has been found that the nonwoven fabric does not hydrolyze. did. Since it does not hydrolyze, the method for producing the polyester nonwoven fabric of the present invention is:
The drying step could be omitted, the change in molecular weight was small even without the drying step, the change in melt viscosity was small, and the nonwoven fabric manufacturing method was stable. Since the polyester nonwoven fabric of the present invention is not easily hydrolyzed, the fiber strength is maintained, the performance is stable,
Excellent nonwoven fabric performance, good texture and moderate strength. For this reason, the polyester nonwoven fabric of the present invention can be effectively used for applications such as filter materials, oil / water separation materials, clean room clothing, and base fabrics for artificial leather.
Therefore, the industrial significance of the method of the present invention is very large.

[0015]

EXAMPLES Next, the present invention will be specifically described with reference to examples. The various characteristic values shown in the examples and comparative examples were measured as follows.

(1) The molar ratio of the diol component of the polyester copolymer The molar ratio of the diol component was determined by measuring a nuclear magnetic resonance spectrum.

(2) Intrinsic Viscosity Using phenol / tetrachloroethane (6/4) as a solvent, the viscosity was measured at 30 ° C. and calculated by extrapolation.

(3) Moisture content Trace moisture analyzer VA-06 / VA- manufactured by Mitsubishi Kasei Corporation
05 using the Karl Fischer method.

(4) Average Fiber Diameter The nonwoven fabric was observed with a scanning electron microscope, and after taking a photograph, the average fiber diameter was randomly measured from the enlarged and baked photograph, and the average value was calculated.

(5) Non-woven fabric strength A sample having a width of 2 cm and a length of 15 cm was prepared in the longitudinal direction and the transverse direction.
0, effective sample length 10cm, chuck margin 2.5c
The elongation strain was recorded until breakage at 100% elongation as m, and the unit weight per unit of 1 cm from the maximum strain stress point (1 g /
m ² ).

(6) Filter Performance Using a light scattering type automatic particle counter KC-01C of Rion Co., Ltd., 0.3 by air suction method.
The dust of μ or more was measured at an average suction air volume of 488 ml / min. Collection Efficiency The number of particles with and without the nonwoven fabric (blank) was read by a particle counter and calculated by the following formula. (Number of blank particles−Number of particles with nonwoven fabric) / (Number of blank particles) × 100 Pressure loss The differential pressure before and after the nonwoven fabric was measured with a fine differential pressure gauge.

Examples and Comparative Examples 2,2-carbon atoms having a molar ratio of about 1.3 times that of dimethyl terephthalate (DMT) and DMT shown in [Table 1] are 2,2.
The above alkyl-substituted 1,3-propanediol was mixed, and as a catalyst, 7.0 × 10 ⁻⁴ mol of zinc acetate / mol of acid component and 2.5 × 10 ⁻⁴ mol of antimony trioxide / mol of acid component were used. The mixture was heated at 200 to 205 ° C. for 1 hour under a nitrogen stream. Next, ethylene glycol (EG) was added so that the total amount of the diol was in a molar ratio of 1: 5 with respect to DMT,
Heated for an additional 2 hours. Then, the mixture is heated at 270 to 275 ° C. for 1 hour to distill off the excess diol, and furthermore, about 0.3 to
The polycondensation was performed at 280 to 285 ° C. under a reduced pressure of 0.5 Torr so as to have a predetermined intrinsic viscosity.

After the obtained polyester copolymer was stored in the form of pellets in the air for 3 months, the intrinsic viscosity and moisture content of the pellets were measured, and the pellets were directly heated and melted by an extruder without drying. .3mmφ orifice is 501
Discharged from a melt blow nozzle with a die width of 600 mm arranged in a row at a pitch of 1 mm, and a slit width of 0.5 mm
Heated air was injected from the slits to collect the fine fibers on a wire mesh belt conveyer running therebelow to collect a melt blown web. The characteristic values of the obtained nonwoven fabric are shown in Table 1. As can be seen from Table 1, according to the present invention, even in the case of pellets containing water, the difference between the intrinsic viscosity of pellets and the intrinsic viscosity of nonwoven fabric is small without a drying step, and the pellets are not hydrolyzed. Turns out,
Excellent spinning stability. A polyester non-woven fabric having strong fiber retention, excellent filter performance and good texture was obtained.

[0024]

[Table 1]

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI D04H 3/00 D04H 3/00 (58) Investigated field (Int.Cl. ⁷ , DB name) D04H 1/00-18/00 D01F 1/00-6/96 C08G 63/183

Claims (3)

(57) [Claims] 1. A polyester nonwoven fabric comprising a polyester copolymer comprising terephthalic acid, ethylene glycol and alkyl-substituted 1,3-propanediol having 2,2-carbon atoms of 2 or more. 2. A diol component wherein the molar ratio of the alkyl-substituted-1,3-propanediol having 2,2-carbon number of 2 or more in the diol component is 3 to 50 mol%, and the alkyl-substituted -1,2-propanediol of 2 or more in number is 2 2. The polyester nonwoven fabric according to claim 1, wherein the alkyl of 2,3-propanediol comprises a group selected from an ethyl group, a propyl group, a butyl group and a pentyl group. 3. Polycondensation of terephthalic acid, ethylene glycol and 2,2-alkyl-substituted-1,3-propanediol having 2 or more carbon atoms together with a catalyst to give an intrinsic viscosity of 0.1.
A polyester copolymer of 2 to 1.0 is obtained, and the polyester copolymer is heated and melted by an extruder as it is without drying, and is a single component type, a parallel composite type, a sheath-core composite type, a multi-segment composite type or a sea-island. 3. The method for producing a polyester nonwoven fabric according to claim 1, wherein the polyester composite nonwoven fabric is spun by a regular method, a melt blow method or a spun bond method using a mold composite die, and an adhesive, a heating self-melting method or a papermaking method.