JPH073527A - Production of modified polyester fiber - Google Patents

Abstract

PURPOSE:To stably produce a modified polyester fiber having good dynamic characteristic and free from unevenness of quality regardless of using liquid modifier. CONSTITUTION:A liquid modifier obtained by blending 100 pts.wt. of a liquid polyester dispersing medium with 0.1-100 pts.wt. of a functionality-providing agent and 1-20 pts.wt. of an aromatic monocarbodiimide is added to a melt of polyester and then the mixture is melt-spun.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified polyester fiber to which a functionalizing agent is added and compounded. More specifically, a method of using a liquid modifier in which an aromatic monocarbodiimide is blended in a liquid polyester dispersion medium in addition to a functionality-imparting agent, which is capable of extremely stably producing a modified polyester fiber having excellent fiber physical properties and small quality unevenness. Regarding

[0002]

2. Description of the Related Art Polyester typified by polyethylene terephthalate is widely used as various molded products such as fibers, films, bottles and the like because of its excellent heat resistance, light resistance and mechanical properties. In order to impart various properties to such molded articles, various functional imparting agents have been conventionally added and blended, and various addition methods have been proposed. For example, taking as an example the case of incorporating a colorant as a functionality-imparting agent,
A method of directly adding a colorant to polyester, blending it in polyester at a high concentration to produce a master chip,
A method of adding this to the polyester at the time of molding, or a method of dispersing it in a liquid dispersion medium in advance and adding it to the polyester in a liquid state (for example, JP-A-63-11).
7071, JP-A-60-45690, etc.) have been proposed. The method of using a material in which a colorant is previously dispersed in a liquid dispersion medium (a liquid colorant) is easy to handle, there is little contamination during premixing (when the colorant is dispersed in the liquid dispersion medium), and coloring is performed. It has been widely used in recent years because it has a feature that the time required for switching a liquid colorant at the time of manufacturing a molded product is short and that it can be easily compounded at the time of molding a molded product such as a fiber, a film and the like.

[0003]

However, the conventionally proposed dispersion medium has insufficient heat resistance and deteriorates the color tone and mechanical properties of the molded product obtained by thermal decomposition at the melt molding temperature of polyester, It has high reactivity with polyester and deteriorates the mechanical properties of the molded product obtained by reacting the dispersion medium with polyester before mixing into polyester and molding, or insufficient kneadability with polyester. However, there is a problem that the quality is not uniformly mixed and the quality unevenness becomes large, and the modified polyester fiber which is practically satisfactory has not yet been obtained.

The present invention has been made in view of the above circumstances, and an object thereof is to produce a modified polyester fiber having good mechanical properties and free from quality unevenness while using a liquid modifier, in an extremely stable manner. To provide a way to do it.

[0005]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that by adding a specific amount of carbodiimide to a polyester liquid dispersion medium in advance, the mechanical properties of the fiber obtained can be improved. The inventors have found that the characteristics are improved, and that the dispersibility of the function-imparting agent in the polyester is improved to reduce quality unevenness, and thus the present invention has been achieved.

That is, according to the present invention, 100 parts by weight of a liquid polyester dispersion medium which is liquid at room temperature in a polyester melt is provided with a functional agent such as a pigment, a dye, an antibacterial agent and an ultraviolet absorber. Provided is a method for producing a modified polyester fiber, characterized in that 0.1 to 100 parts by weight and a liquid modifier containing 1 to 20 parts by weight of an aromatic monocarbodiimide are added and mixed, followed by melt spinning. It

The present invention will be described in detail below. In the present invention, as a medium for dispersing the functionalizing agent,
It is not particularly limited as long as it is a liquid polyester at room temperature, for example, adipic acid, sebacic acid, aliphatic dicarboxylic acids such as azelaic acid, phthalic acid, aromatic dicarboxylic acids such as naphthalene dicarboxylic acid as an acid component, ethylene glycol, Examples of the polyester include propylene glycol, tetramethylene glycol, neopentyl glycol, diethylene glycol and cyclohexanedimethanol as a glycol component. In addition, copolymers of these polyesters with polyfunctional components such as trimellitic acid, glycerin, pentaerythritol, and sorbitol, mono-alcohols such as n-octyl alcohol, 2-ethylhexyl alcohol, and n-decyl alcohol at the terminals or olein. Acid, lauric acid or other monovalent carboxylic acid blocked, polyethylene glycol,
It is also possible to use a copolymer of polyalkylene glycol such as polypropylene glycol. Above all,
Aliphatic polyesters such as polypropylene sebacate are preferable because the effect of the present invention is great.

Such a liquid polyester is relatively stable even at the melt spinning temperature of a fiber-forming polyester typified by polyethylene terephthalate, and has a low viscosity, so that it flows at room temperature even when various functional additives are blended. In addition, it has a good compatibility with polyester, and therefore has a feature that the dispersibility of the function-imparting agent in the polyester resin is good.

As the function-imparting agent to be added to the above-mentioned dispersion medium, any function-imparting agent conventionally used for modifying polyester fibers can be used. For example, an antistatic property-imparting agent, a fluorescent whitening agent, UV absorber, light stabilizer, matting agent, coloring pigment,
Examples thereof include dyes. In particular, when a coloring pigment or dye is blended, in general, even a very slight dispersion unevenness is easily detected as a colored unevenness, but according to the method of the present invention, the liquid modifier is uniformly dispersed in the polyester. It is particularly preferable because it is possible.

Examples of pigments or dyes that are preferably used include organic pigments such as azo, phthalocyanine, quinacridone, anthraquinone, dioxazine, and perylene / perinone, iron oxide, titanium oxide, ultramarine, carbon black and the like. Inorganic pigments and dyes such as azo-based, anthraquinone-based, perylene-based, phthalocyanine-based, and heterocyclic-based dyes, which may be used alone or in combination, and the pigment and dye may be used in combination. May be.

The proportion of the functional-imparting agent mixed in the liquid dispersion medium varies depending on the type of the agent used and the degree of modification of the polyester, but usually the dispersion medium 100 is used.
0.1 to 100 parts by weight is preferable with respect to parts by weight. If the blending amount is less than 0.1 parts by weight, the amount of the liquid modifier necessary for modifying the polyester increases, and the mechanical properties of the resulting fiber deteriorate, which is not preferable. On the other hand, if the amount exceeds 100 parts by weight, it becomes difficult to disperse the liquid modifier in the polyester, and it becomes impossible to obtain fibers of uniform quality, which is not preferable.

In the present invention, when the above-mentioned functionality-imparting agent is added to the liquid dispersion medium, 1 to 20 parts by weight, preferably 1 to 10 parts by weight of aromatic monocarbodiimide is added to 100 parts by weight of the dispersion medium (liquid polyester). It is essential to blend in parts by weight. If the blending amount is less than 1 part by weight, the mechanical properties of the resulting fiber and the kneading property are deteriorated, so that the tone of the spinning process is deteriorated. On the other hand, when it exceeds 20 parts by weight, coloring of the obtained fiber is promoted and heat resistance is deteriorated, which is not preferable.

Examples of the aromatic monocarbodiimide used here include 2,2'-dimethyldiphenylcarbodiimide, 2,2'-diisopropylcarbodiimide, 2,2'-diethoxydiphenylcarbodiimide,
2,6,2 ', 6'-tetraisopropyldiphenylcarbodiimide, 2,4,6,2', 4 ', 6'-hexaisopropyldiphenylcarbodiimide and the like can be mentioned, particularly 2,6,2', 6 ′ -Tetraisopropyldiphenylcarbodiimide has good heat resistance and does not easily generate decomposition gas during spinning, and the detailed reason for this is unknown, but the viscosity of the liquid modifier obtained when mixed in the liquid dispersion medium is large. Therefore, even if the amount of the functional-imparting agent in the liquid modifier is increased, it becomes easy to disperse it in the polyester melt, and the modified polyester fiber having good mechanical properties and less quality unevenness is stable. It is not preferable because it has the characteristic of being obtained.

The viscosity of the liquid modifier compounded with the functionality-imparting agent and the aromatic monocarbodiimide is 2,000 poise or less at room temperature, preferably 1500 at the normal temperature in view of the handling property and the measurement accuracy when it is added and mixed into the molten polyester. It is desirable to be less than or equal to poise. When it exceeds 2000 poise, not only the fluidity is deteriorated and the handleability is deteriorated, but also the measurement accuracy is deteriorated and the quality unevenness is apt to occur.

The method of blending the functionalizing agent and the aromatic monocarbodiimide into the liquid dispersion medium is not particularly limited,
It can be compounded by a usual method. For example, a dispersing / kneading machine such as a kneader, a ball mill, a sand mill, or a triple roll can be used, and these can be used together. The order of compounding is not particularly limited, and the functionalizing agent and the carbodiimide may be compounded simultaneously or separately. Above all, it is preferable to mix carbodiimide first, because the viscosity of the mixture is lowered and the kneading of the functionalizing agent is facilitated in many cases.

In the present invention, the polyester to which the above-mentioned liquid modifier is added is mainly composed of a polyester whose repeating unit is mainly ethylene terephthalate, but the third component other than the terephthalic acid component and / or the ethylene glycol component. A small amount (usually 20 mol% or less with respect to the terephthalic acid component) may be copolymerized. The intrinsic viscosity of the polyester is preferably 0.6 or more, more preferably 0.8 or more from the viewpoint of the mechanical performance of the obtained fiber.

It is not necessary to employ a special method for adding and blending the liquid modifier into the molten polyester. For example, after the liquid modifier is injected and added into the molten polyester before spinning while being measured by a gear pump or the like. , A static mixer, and the like, and then discharging from a spinneret. Here, the amount of the liquid modifier added varies depending on the amount of the function-imparting agent blended in the liquid modifier and the required degree of modification, but usually 100 parts by weight of molten polyester is used. It is desirable that the amount is 1 to 11 parts by weight.

When the amount of the liquid modifier to be added is less than 1 part by weight based on 100 parts by weight of the molten polyester, the desired degree of modification cannot be obtained, or dispersion becomes difficult and quality unevenness occurs. It tends to occur easily. On the other hand, if the amount exceeds 11 parts by weight, the mechanical properties of the obtained fiber are often deteriorated and the yarn-making process is sick.

The polymer discharged from the spinneret may be drawn by a conventional method, for example, at a drawing speed of 1000 m / min, and then drawn at a draw ratio at which a desired elongation can be obtained.

[0020]

The reason why the modified polyester fiber having good mechanical properties and no quality unevenness can be stably obtained by the above-described production method of the present invention has not been clarified in detail, but It is estimated as. That is,
Since the aromatic monocarbodiimide used in the present invention blocks the functional groups at the molecular chain terminals of the liquid polyester dispersion medium and the polyester, the thermal decomposition of the dispersion medium and the reaction between the dispersion medium and the polyester are suppressed. Further, in order to increase the degree of polymerization by partially binding the molecular chain ends of the polyester,
Deterioration of the degree of polymerization is also suppressed. Furthermore, since the viscosity of the dispersion medium is reduced, the dispersibility in the molten polyester becomes good even if the amount of the functionalizing agent is increased. as a result,
Trouble such as deterioration of mechanical properties of fiber due to thermal decomposition / thermal reaction of dispersion medium or breakage during spinning is reduced, and problems such as quality unevenness due to dispersion unevenness of the function-imparting agent and deterioration of spinning stability are also caused. It will decrease.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The characteristic values in the examples were measured by the following methods.

(Strength and Elongation) Using an Instron type tensile tester, sample length 25 cm, tensile speed 30 cm / mi
It was measured by n.

(Quality unevenness) Stretched yarn is knitted on a sock knitted fabric,
A drawn yarn of a standard color was visually compared with a similarly knitted yarn, and a yarn in which a clear color difference was observed was defined as a quality fluff yarn, which was expressed as a ratio of the quality fluff yarn to the total number of visually compared.

(Lightfastness) Pigmented polyester fiber is used as a tubular knitted fabric and a carbon arc fade-o-meter FAL-3H type manufactured by Suga Test Instruments Co., Ltd. is used at a black panel temperature of 83 ± 3 ° C. for 400 hours. UV irradiation,
The degree of discoloration was judged on a gray scale (grade).

(Spinning Breakage Rate) Spinning was performed at a winding speed of 1100 m / min, and the number of breaks per 10 ⁶ m of winding length was expressed.

(Drawing breakage rate) The drawing breakage was drawn at a drawing speed of 1000 m / min, and expressed by the number of breaks per drawn yarn length of 3 × 10 ⁵ m.

[0027]

Example 1 After adding 5 parts by weight of carbodiimide to 100 parts by weight of the liquid polyester shown in Table 1, 8 parts by weight of phthalocyanine blue, 2 parts by weight of quinacridone red,
0.2 parts by weight of carbon black was kneaded with a three-roll mill to obtain a liquid modifier having a viscosity of 400 poise.

Intrinsic viscosity of 0.6 at 290 ° C.
In polyethylene terephthalate of 5, the above liquid modifier was quantitatively supplied by a gear pump at a ratio of 5 parts by weight to 100 parts by weight of the molten polyester, and then mixed in a pipe having a static mixer manufactured by Kenix. Then, it was extruded from a spinneret having 24 discharge holes at a discharge rate of 30 g / min and wound up at a speed of 1100 m / min. The obtained undrawn yarn was drawn 3.6 times according to a conventional method,
A blue colored polyester fiber was obtained.

As shown in Table 1, the obtained colored polyester fiber was a uniform yarn with few modified spots, and the process condition at the time of yarn production was good.

[0030]

Examples 2 to 9 and Comparative Examples 1 to 4 In Example 1, the liquid polyester and the function-imparting agent were replaced with those shown in Table 1, and a liquid modifier was obtained in the same manner as in Example 1.

The obtained liquid modifier was added to and mixed with molten polyethylene terephthalate in the same manner as in Example 1 and then spin-drawn to obtain a modified polyester fiber. The results are summarized in Table 1.

[0032]

[Table 1]

In the table, the dispersant A is polypropylene sebacate having an average molecular weight of 8000, an acid value of 2 mgKOH / g and a hydroxyl value of 15 mgKOH / g, and the dispersant B is an average molecular weight of 400.
0, acid value 1.5 mgKOH / g, hydroxyl value 12 mgKO
H / g polypropylene sebacate, dispersant C is 2,2
-Bis (4- (β-palmitoxyethoxy) phenyl)
Represents propane, monocarbodiimide (a) is 2,
6,2 ′, 6′-tetraisopropyldiphenylcarbodiimide, monocarbodiimide (II) represent 2,2′-dimethyldiphenylcarbodiimide, and the functionalizing agent a is 8 parts by weight of phthalocyanine blue, 2 parts by weight of quinacridone red, A mixed blue pigment containing 0.2 part by weight of carbon black, and the function-imparting agent b are 2 parts by weight of the above blue pigment, Tinubin 320 manufactured by Ciba-Geigy as an ultraviolet absorber, and Chimassorb 994 manufactured by Ciba-Geigy as a light stabilizer.
It is a mixture of 2 parts by weight.

[0034]

As is apparent from the above, according to the production method of the present invention, various functionalizing agents are uniformly dispersed in the polyester, which is a homogeneous modified polyester excellent in mechanical properties and having less quality unevenness. The fibers can be manufactured extremely stably.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location D01F 1/10 7199-3B

Claims (3)

[Claims] 1. A polyester melt containing 100 parts by weight of a liquid polyester dispersion medium which is liquid at room temperature,
Melt after adding and mixing a liquid modifier containing 0.1 to 100 parts by weight of a functionalizing agent such as a pigment, a dye, an antibacterial agent, and an ultraviolet absorber, and 1 to 20 parts by weight of an aromatic monocarbodiimide. A method for producing a modified polyester fiber, which comprises spinning. 2. The method for producing a modified polyester fiber according to claim 1, wherein the compounding amount of the liquid modifier is 1 to 11 parts by weight based on 100 parts by weight of the polyester melt. 3. The aromatic monocarbodiimide is 2,6.
The method for producing a modified polyester fiber according to claim 1, which is 2 ', 6'-tetraisolopyrdiphenylcarbodiimide.