JP2709235B2 - Polyester crimped fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll made of an aliphatic polyester having biodegradability, a practically sufficient high molecular weight and specific melting characteristics, and having good crimpability and elastic recovery. Concerning the compressed fiber.

[0002]

2. Description of the Related Art In recent years, synthetic (plastic) fibers have been used instead of animal and vegetable fibers in clothing and residential interiors. Has the potential to contaminate the oceans and soil, and has become a major social problem. For the prevention of this pollution, the emergence of biodegradable plastics has been anticipated and has already been manufactured, for example, by fermentation using microorganisms. A blend of starch, which is poly (3-hydroxybutyrate) or a blend-type natural polymer, and a general-purpose plastic is known. However, the former has a drawback in that since the thermal decomposition temperature of the polymer is close to the melting point, the molding processability is inferior, and microorganisms create the raw material unit, which is very poor.
In the latter, since the natural polymer itself is not thermoplastic, there is a difficulty in moldability, and the use range is greatly restricted.
On the other hand, although aliphatic polyesters are known to have biodegradability, they have hardly been used because a high molecular weight product sufficient for obtaining practical molded article properties cannot be obtained. Recently, ε-caprolactone has been found to have a high molecular weight by ring-opening polymerization, and has been proposed as a biodegradable resin. However, the melting point is as low as 62 ° C. ing. Glycolic acid and lactic acid also have high molecular weights by ring-opening polymerization of glycolide and lactide, and are slightly used for medical fibers, etc. Or, it has not been used in large quantities for residential interiors.

[0003] As one of these materials for clothing and housing interiors, high molecular weight polyesters generally used for forming crimped fibers (the high molecular weight polyester referred to herein has a number average molecular weight of 10,000 or more) Refers to
Is limited to polyethylene terephthalate, which is a condensate of terephthalic acid (including dimethyl terephthalate) and ethylene glycol. In some cases, 2,6-naphthalenedicarboxylic acid is used in place of terephthalic acid, but in any case, no attempt has been made to impart biodegradability. Therefore,
Conventionally, there is no thought to form a crimped fiber using a biodegradable aliphatic polyester using an aliphatic type dicarboxylic acid and put it into practical use.
One of the reasons why this idea of practical use has not been born is that even if the crimped fiber is crystalline even though special molding conditions and physical properties of the molded article are required, the aliphatic polyester In most cases, the melting point of the polyester is less than 100 ° C., and furthermore, the thermal stability at the time of melting is poor, and more importantly, the properties of this aliphatic polyester, particularly the mechanical properties represented by tensile strength, are low. However, even at the same level of the number average molecular weight as the above polyethylene terephthalate, the compound showed a remarkably inferior value, and it is considered that it was difficult to make a concept of obtaining a molded product requiring strength or the like.
Further, it is inferred that one of the reasons is that the study for further improving the physical properties by further increasing the number average molecular weight of the aliphatic polyester has not sufficiently progressed due to poor thermal stability.

[0004]

SUMMARY OF THE INVENTION The present invention uses these aliphatic polyesters as components, has a practically sufficient high molecular weight, and is excellent in mechanical properties represented by thermal stability and tensile strength. Also, it is an object of the present invention to provide a crimped fiber which is biodegradable as one of disposal means, that is, can be decomposed by microorganisms and the like, is easy to dispose after use, and has excellent crimpability and elastic recovery. Make it an issue.

[0005]

Means for Solving the Problems The present inventors have studied various reaction conditions for obtaining a polyester having a high molecular weight and sufficient practicality and having crimped fiber moldability. While obtaining a specific aliphatic polyester having a practically sufficient high molecular weight, the crimped fiber molded from this has not only the above-mentioned biodegradability, but also has excellent crimpability, elastic recovery properties, and excellent texture. It was completed.

That is, the gist of the present invention is that (A) a glycol and a polybasic acid (or an anhydride thereof) are mainly used as constituents at a temperature of 190 ° C. and a shear rate of 1,000 sec ^−1.
A melt viscosity of 1.0 × 10 ^{2 to} 1.0 × 10 ⁴ poise, and a crimped fiber extruded from an aliphatic polyester having a melting point of 70 to 190 ° C. as a main component;
(B) The aliphatic polyester has a number average molecular weight of 10,000.
The crimped fiber (A) containing a urethane bond in an amount of 0.03 to 3.0% by weight and (C) having a number average molecular weight of 5,000
(A) or (B) using an aliphatic polyester obtained by reacting 0.1 to 5 parts by weight of a diisocyanate with 100 parts by weight of an aliphatic polyester prepolymer having a melting point of 0 or more and 60 ° C. or more. ) Crimped fiber,
(D) The crimped fiber of (A), (B) or (C) having a tensile strength of 2.0 to 10.0 g / d and a tensile elongation of 10 to 120%. Hereinafter, the contents of the present invention will be described in detail.

[0007] The aliphatic polyester referred to in the present invention is a polyester containing a polyester synthesized from a glycol and a polybasic acid (or an acid anhydride thereof) as a main component. A relatively high molecular weight polyester prepolymer having a group was selected and further reacted with a coupling agent.

Conventionally, a low molecular weight polyester prepolymer having a number average molecular weight of 2,000 to 2,500 having a hydroxyl group as a terminal group is reacted with a diisocyanate as a coupling agent to form a polyurethane, Foams, paints and adhesives are widely used. However, polyester prepolymers used for these polyurethane foams, paints and adhesives are:
The maximum number average molecular weight that can be synthesized without a catalyst is 2,0
It is a low molecular weight prepolymer of 100 to 2,500, and in order to obtain practical physical properties as a polyurethane with respect to 100 parts by weight of the low molecular weight prepolymer, the amount of diisocyanate used is 10 to 20 parts by weight. When such a large amount of diisocyanate is added to a low-molecular-weight polyester melted at 150 ° C. or higher, gelation occurs and a normal melt-moldable resin cannot be obtained.
Therefore, a polyester obtained by using such a low molecular weight polyester prepolymer as a raw material and reacting a large amount of diisocyanate cannot be used as the raw material for crimped fibers of the present invention.

As in the case of polyurethane rubber, a method of converting a hydroxyl group into an isocyanate group by adding a diisocyanate and further increasing the number average molecular weight with a glycol may be considered. As described above, the amount is 10 parts by weight or more based on 100 parts by weight of the prepolymer, so that practical properties are obtained. If a polyester prepolymer having a relatively high molecular weight is to be used, the heavy metal catalyst required for the synthesis of the prepolymer significantly promotes the reactivity of the isocyanate group used in the above amount, resulting in poor storage stability, crosslinking reaction, and branching. Since it is not preferable to use a polyester prepolymer synthesized without a catalyst as a polyester prepolymer, the number average molecular weight is limited to about 2,500 at the highest even if it is high.

The polyester prepolymer for obtaining the aliphatic polyester used in the present invention has a relatively high molecular weight as described above containing a catalyst for the synthesis thereof,
A saturated aliphatic polyester having a terminal group substantially a hydroxyl group, a relatively high molecular weight having a number average molecular weight of 5,000 or more, preferably 10,000 or more, and a melting point of 60 ° C. or more; And a polybasic acid (or an anhydride thereof) in a catalytic reaction. When the number average molecular weight is less than 5,000, for example, about 2,500, a small amount of coupling agent of 0.1 to 5 parts by weight used in the present invention can provide a polyester for crimped fiber having good physical properties. Can not do. A polyester prepolymer having a number average molecular weight of 5,000 or more has a hydroxyl value of 3
0 or less, and by using a small amount of coupling agent, even under severe conditions such as a molten state, it is not affected by the remaining catalyst, so that a high molecular weight polyester can be synthesized without generating a gel during the reaction. .

The glycols used include, for example, ethylene glycol, 1,4-butanediol, 1,6
-Hexanediol, decamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like. Ethylene oxide can also be used. These glycols may be used in combination.

Polybasic acids (or their anhydrides) which react with glycols to form aliphatic polyesters include:
Succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, succinic anhydride, adipic anhydride, and the like are generally commercially available and can be used in the present invention. Polybasic acids (or acid anhydrides thereof) may be used in combination.

These glycols and polybasic acids are mainly composed of aliphatic compounds, but may be used in combination with small amounts of other components such as aromatic compounds. However, if other components are introduced, the biodegradability deteriorates, so the content is 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less.

The polyester prepolymer for aliphatic polyester used in the present invention has a terminal group substantially a hydroxyl group. For this purpose, glycols and polybasic acids (or acid anhydrides thereof) used in the synthesis reaction are used. Requires that the glycols be used in some excess.

In order to synthesize a relatively high molecular weight polyester prepolymer, it is necessary to use a deglycol-reaction catalyst during the deglycolization reaction following the esterification. Examples of the deglycol-reaction catalyst include titanium compounds such as acetoacetoyl-type titanium chelate compounds and organic alkoxytitanium compounds. These titanium compounds can be used in combination. Examples of these include diacetacetoxyoxytitanium ("Narcem Titanium" manufactured by Nippon Chemical Industry Co., Ltd.), tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium and the like. The use ratio of the titanium compound is 0.001 to 100 parts by weight of the polyester prepolymer.
1 part by weight, desirably 0.01 to 0.1 part by weight.
The titanium compound may be added from the beginning of the esterification, or may be added immediately before the deglycolization reaction.

Furthermore, the number average molecular weight is 5,000 or more,
Desirably, a coupling agent is used to further increase the number average molecular weight of the polyester prepolymer in which 10,000 or more terminal groups are substantially hydroxyl groups. Examples of the coupling agent include diisocyanates, oxazolines, diepoxy compounds, acid anhydrides, and the like.
Particularly, diisocyanate is preferable. In the case of an oxazoline or diepoxy compound, it is necessary to react a hydroxyl group with an acid anhydride or the like and convert the terminal to a carboxyl group before using a coupling agent. The type of diisocyanate is not particularly limited, and examples thereof include the following types. 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, Hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, particularly hexamethylene diisocyanate, are preferred from the viewpoint of the hue of the formed resin, the reactivity when adding polyester, and the like.

The amount of the coupling agent to be added is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight based on 100 parts by weight of the polyester prepolymer. If the amount is less than 0.1 part by weight, the coupling reaction is insufficient. If the amount exceeds 5 parts by weight, gelation is liable to occur.

The addition is desirably carried out under conditions where the polyester prepolymer is in a homogeneous molten state and can be easily stirred. It is not impossible to add to the solid polyester prepolymer and melt and mix through an extruder, but it is added to the aliphatic polyester production equipment or to the molten polyester prepolymer (for example, in a kneader). It is practical to do.

The aliphatic polyester used in the present invention is required to have a specific melting property in order to extrude into a fiber having crimpability. That is, the melt viscosity at a temperature of 190 ° C. and a shear rate of 1,000 sec ⁻¹ is 1.0 ×
10 ^{2 to} 1.0 × 10 ⁴ poise, preferably 2.
0 × 10 ^{2 to} 6.0 × 10 ³ poise, 3.0 × 10 ² to
4.0 × 10 ³ poise is particularly preferred. 1.0 × 10 ²
If it is less than poise, operability is poor and crimped fibers having sufficient strength cannot be obtained. If it exceeds 1.0 × 10 ⁴ poise, thread breakage at the nozzle occurs, making spinning difficult. The melt viscosity was measured with a nozzle diameter of 1.0 mm and L / D = 1.
From the graph of the relationship between the shear rate measured at a resin temperature of 190 ° C. and the apparent viscosity using a nozzle No. 0, the shear rate was 1,000 s.
The viscosity at ec ^-1 was determined.

Further, the melting point of the aliphatic polyester used in the present invention needs to be 70 to 190 ° C, more preferably 70 to 150 ° C, and particularly preferably 80 to 135 ° C. If it is lower than 70 ° C., the heat resistance is insufficient, and if it is higher than 190 ° C., it is difficult to manufacture.
If the melting point is 70 ° C. or more and the crystallinity is obtained, it is possible to obtain a crimped fiber excellent in crimpability, elastic recovery property and texture, and can be used for carpets, clothing and the like. 70
In order to obtain a melting point of not lower than 60 ° C., the melting point of the polyester prepolymer needs to be not lower than 60 ° C.

When the aliphatic polyester used in the present invention contains a urethane bond, the amount of the urethane bond is from 0.03 to 3.0% by weight, preferably from 0.05 to 2.0% by weight, more preferably from 0.1 to 2.0% by weight. Particularly preferred is 1 to 1.0% by weight.
The urethane bond amount is measured by C ₁₃ NMR and agrees well with the charged amount. If it is less than 0.03% by weight, the effect of increasing the molecular weight by the urethane bond is small, and the molding processability is poor,
If it exceeds 3.0% by weight, a gel is generated.

When using the above-mentioned aliphatic polyester for forming the crimped fiber according to the present invention, a lubricant, a wax, a coloring agent, etc., as necessary, in addition to an antioxidant, a heat stabilizer, an ultraviolet absorber, etc. Of course, a crystallization accelerator or the like can be used in combination. That is, examples of the antioxidant include hindered phenol-based antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole, and sulfur-based antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate. Agents, heat stabilizers such as triphenyl phosphite, trilauryl phosphite, trisnonyl phenyl phosphite, and ultraviolet absorbers such as pt-butylphenyl salicylate;
2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like,
Lubricants such as calcium stearate, zinc stearate, barium stearate and sodium palmitate; antistatic agents such as N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate, alkyl sulfonate, etc. Hexabromocyclododecane, Tris- (2,3
-Dichloropropyl) phosphate, pentabromophenyl allyl ether and the like.

The raw material containing aliphatic polyester as a main component used in the present invention is usually melt-spun, air-cooled,
Fiberized by hot drawing. Spinning temperature is 170-240
° C, preferably 180 to 210 ° C. If the melting point is close to the melting point, the spinning is likely to occur. The stretching is performed by a heating roll. Stretching temperature is 5
The temperature is 0 to 100 ° C, preferably 70 to 90 ° C. 50 ℃
If it is less than 10, the stretchability is extremely reduced. On the other hand, when the temperature is 100 ° C. or more, not only the stretchability is extremely lowered, but also the stretch breakage easily occurs. The crimping temperature is 60 to 100 ° C, preferably 75 to 90 ° C. If the temperature is lower than 60 ° C., a crimped fiber having a sufficient crimp rate cannot be obtained.

[0024]

The present invention will be described below with reference to examples and comparative examples.

Example 1 A reactor of 700 L was purged with nitrogen and charged with 183 kg of 1,4-butanediol and 224 kg of succinic acid. Raise the temperature under a nitrogen stream and
3.0 hours at 95 to 210 ° C.
The esterification reaction by dehydration condensation was performed under reduced pressure of 5 to 5 mmHg for 3.5 hours. The collected sample is
Acid value is 6.3 mg / g, number average molecular weight (Mn) is 5.2
The weight average molecular weight (Mw) was 10,100. Subsequently, 34 g of tetraisopropoxy titanium as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature,
The deglycol-reaction was performed at a temperature of 215 to 220 ° C. under a reduced pressure of 5 to 0.2 mmHg for 7.5 hours. The collected sample had a number average molecular weight (Mn) of 18,600 and a weight average molecular weight (Mw) of 50,300. The yield of this polyester (A1) is 339 kg excluding condensed water.
Met.

To a reactor containing 339 kg of polyester (A1), 4.07 kg of hexamethylene diisocyanate was added, and a coupling reaction was carried out at 180 to 200 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Then, Irganox 1010 was used as an antioxidant.
1.70 kg (manufactured by Ciba Geigy) and 1.70 kg of calcium stearate as a lubricant were added, and stirring was further continued for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. The yield of the polyester (B1) after vacuum drying at 90 ° C. for 6 hours was 270 kg.

The obtained polyester (B1) is a slightly ivory white wax-like crystal having a melting point of 110.
° C, the number average molecular weight (Mn) is 29,500, the weight average molecular weight (Mw) is 127,000, the MFR (190 ° C) is 9.2 g / 10 min, the viscosity of a 10% solution of orthochlorophenol is 170 poise, Temperature 190 ° C, shear rate 10
The melt viscosity at 00 sec ^-1 was 3.0 × 10 ³ poise. The average molecular weight is measured by Shodex GPC
System-11 (Showa Denko KK gel chromatography), solvent of CF ₃ COONa HFIPA5mm
ol solution, concentration 0.1% by weight, calibration curve is Showa Denko KK
PMMA standard sample Shodex Standard
d Performed on M-75.

The polyester (B1) was melt-spun from a 68-hole extruder having a screw diameter of 40 mmφ, a nozzle diameter of 0.6 mmφ and a screw temperature of 190 ° C., a head temperature of 200 ° C., and a nozzle temperature of 205 ° C. After applying the sizing agent to the extruded undrawn multifilament by a roller,
The film was stretched 6 times at a temperature of 80 ° C., and was crimped using heated air at a temperature of 80 ° C. using a crimp nozzle to obtain a crimped yarn. When the strength and elongation of the obtained crimped yarn were measured, the strength was 4.0 g / d,
The elongation was 45%. Note that JIS L1036 and J
When the crimp rate and the crimp modulus were measured by IS L1074, the crimp rate was 13.2 and the crimp modulus was 80.5. This crimp did not change even after the heat treatment at 60 ° C. for 30 minutes. When this crimped fiber was buried in the soil for 5 months, the shape of the crimped fiber was decomposed and changed to such an extent that it did not stop.

Example 2 Using polyester (B1), a screw diameter of 40 mmφ, a nozzle diameter of 0.6 mmφ,
Melt spinning was performed from a 68-hole extruder at a screw temperature of 190 ° C, a head temperature of 200 ° C, and a nozzle temperature of 205 ° C. The extruded undrawn multifilament was stretched 4 times at 70 ° C. after applying a sizing agent with a roller, and then subjected to crimping using a crimp nozzle with heated air at 80 ° C. to obtain a crimped yarn. . When the strength and elongation of the obtained crimped yarn were measured, the strength was 2.9 g / d and the elongation was 70%. JIS L
When the crimp rate and the crimp modulus were measured according to 1036 and JIS L1074, the crimp rate was 10.7 and the crimp modulus was 7
1.5. This crimp did not change even after the heat treatment at 60 ° C. for 30 minutes. When the crimped fiber was buried in the soil for 5 months, the crimped fiber was decomposed and changed to such an extent that the practical strength and the crimp modulus were lost.

Example 3 Using polyester (B1), a screw diameter of 40 mmφ, a nozzle diameter of 0.6 mmφ,
Melt spinning was performed from a 128-hole extruder at a screw temperature of 200 ° C, a head temperature of 210 ° C, and a nozzle temperature of 200 ° C. The extruded undrawn multifilament was stretched 6-fold at 70 ° C. after applying a sizing agent with a roller, and then subjected to crimping using a crimp nozzle with heated air at 80 ° C. to obtain a crimped yarn. . When the strength and elongation of the obtained crimped yarn were measured, the strength was 4.3 g / d and the elongation was 42%. JIS
When the crimping rate and the crimping modulus were measured according to L1036 and JIS L1074, the crimping rate was 17 and the crimping rate was 9
0.4. This crimp did not change even after the heat treatment at 60 ° C. for 30 minutes. When this crimped fiber was buried in the soil for 5 months, it was found that both the high elongation and the crimp elasticity were decomposed and changed to such a degree that they did not have practical values.

(Comparative Example 1) Using polyester (A1), spinning and stretching were performed under the same conditions as in (Example 1).
Crimping was carried out with heated air at a temperature of ° C. Thread breakage occurred during crimping, and stable crimped fibers could not be obtained.

[0032]

According to the present invention, a temperature of 190 ° C. and a shear rate of 1,
The melt viscosity at 000 sec ^-1 is 100 × 10 ² to
A monofilament having 1.0 × 10 ⁴ poises and a main component of an aliphatic polyester having a melting point of 70 to 190 ° C., particularly a number average molecular weight of 5,000 or more and a melting point of 60
A monofilament made of an aliphatic polyester obtained by reacting 0.1 to 5 parts by weight of a diisocyanate with 100 parts by weight of an aliphatic polyester prepolymer at a temperature of 100 ° C. or more is biodegradable when buried in soil or the like. Even if incinerated, the calorific value of combustion is lower than that of polyethylene or polypropylene, and it is excellent in crimpability and elastic recovery, and is useful for carpets and clothing.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08G 63/16 C08G 63/16 63/685 63/685 63/91 63/91 D01F 6/84 306 D01F 6/84 306B // B29K 67:00 (56) References JP-A-61-41321 (JP, A) JP-A-4-108331 (JP, A) JP-A-59-59419 (JP, A) Kaihei 3-200859 (JP, A)

Claims (4)

(57) [Claims] A melt viscosity of 1.0 × 1 at a temperature of 190 ° C. and a shear rate of 1,000 sec ⁻¹ mainly comprising glycols and a polybasic acid (or an anhydride thereof) as constituents.
0 ^{2 to} 1.0 × 10 ⁴ poises and a melting point of 70 to 19
A crimped fiber extruded mainly from an aliphatic polyester at 0 ° C. 2. An aliphatic polyester having a number average molecular weight of 1
The crimped fiber according to claim 1, which has a urethane bond of not less than 000 and 0.03 to 3.0% by weight. 3. A fat obtained by reacting 0.1 to 5 parts by weight of a diisocyanate with 100 parts by weight of an aliphatic polyester prepolymer having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more. 3. The crimped fiber according to claim 1, which is made of an aromatic polyester. 4. The crimped fiber according to claim 1, which has a tensile strength of 2.0 to 10 g / d and a crimp rate of 3 to 20.