JP3231483B2 - Method for producing modified polyester 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 method for producing a modified polyester fiber to which a function-imparting agent is added and blended. More specifically, using a liquid modifier in which an aromatic monocarbodiimide is added to a liquid polyester dispersion medium in addition to a function-imparting agent, a method for producing a modified polyester fiber having excellent fiber physical properties and small unevenness in quality extremely stably. About.

[0002]

2. Description of the Related Art Polyesters represented by polyethylene terephthalate are widely used as various molded articles such as fibers, films and bottles because of their excellent heat resistance, light resistance and mechanical properties. Conventionally, in order to impart various properties to such molded articles, various functionalizing agents have been added and blended, and various adding methods have been proposed. For example, taking a case where a coloring agent is compounded as a function imparting agent,
A method in which a colorant is directly added to and blended into polyester, a master chip is prepared by blending in high concentration in polyester,
A method of adding this to the polyester during molding, or a method of dispersing it in a liquid dispersion medium in advance and adding it in a liquid state to the polyester (for example, JP-A-63-11)
7071, JP-A-60-45690) and the like. The method of using a substance in which a colorant is dispersed in a liquid dispersion medium in advance (liquid colorant) is easy to handle, less contamination during premixing (when the colorant is dispersed in the liquid dispersion medium), and is colored. It has been widely used in recent years because it can be easily compounded at the time of molding fibers, films, and other molded products in addition to the feature that the time required for switching the liquid colorant during the production of molded products is short.

[0003]

However, the dispersion medium proposed in the prior art 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. Highly reactive with the polyester, the dispersion medium reacts with the polyester before the mixture is formed into the polyester and molded, thereby deteriorating the mechanical properties of the molded product obtained, or insufficiently kneading with the polyester However, there is a problem that the mixture 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 such circumstances, and an object of the present invention is to produce a modified polyester fiber having good mechanical properties and no unevenness in quality while using a liquid modifier. It is to provide a method that can be performed.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, by adding a specific amount of carbodiimide in advance to a polyester-based liquid dispersion medium, the mechanical properties of the resulting fiber are improved. The present inventors have found that the properties are improved, and that the dispersibility of the function-imparting agent in the polyester is improved, thereby reducing unevenness in quality.

That is, according to the present invention, a functionalizing agent such as a pigment, a dye, an antibacterial agent, and an ultraviolet absorber is added to 100 parts by weight of a liquid polyester dispersion medium that is liquid at room temperature in a polyester melt. A method for producing a modified polyester fiber, comprising: adding and mixing a liquid modifier containing 0.1 to 100 parts by weight and 1 to 20 parts by weight of an aromatic monocarbodiimide, followed by melt-spinning. You.

Hereinafter, the present invention will be described in detail. In the present invention, as a medium for dispersing the functionality imparting agent,
It is not particularly limited as long as it is a polyester which exhibits a liquid state at normal temperature, for example, adipic acid, sebacic acid, aliphatic dicarboxylic acid such as azelaic acid, phthalic acid, aromatic dicarboxylic acid such as naphthalenedicarboxylic acid as an acid component, ethylene glycol, Examples include polyesters containing propylene glycol, tetramethylene glycol, neopentyl glycol, diethylene glycol, cyclohexane dimethanol, or the like as a glycol component. Further, these polyesters are copolymerized with polyfunctional components such as trimellitic acid, glycerin, pentaerythritol and sorbitol, and are terminated with monohydric alcohols such as n-octyl alcohol, 2-ethylhexyl alcohol, n-decyl alcohol or olein. Acids, those blocked with monovalent carboxylic acids such as lauric acid, further polyethylene glycol,
Those obtained by copolymerizing polyalkylene glycol such as polypropylene glycol can also be used. Above all,
Aliphatic polyesters such as polypropylene sebacate are preferred because of the great effect of the present invention.

Such a liquid polyester is relatively stable even at the melt spinning temperature of a fiber-forming polyester represented by polyethylene terephthalate, and has a low viscosity, so that it can flow at room temperature even when various functionalizing agents are blended. In addition, the polymer has good compatibility with polyester and has good dispersibility of the function-imparting agent in the polyester resin.

As the function-imparting agent to be added to the dispersion medium, any function-imparting agent conventionally used for modifying polyester fibers can be used. For example, an antistatic agent, a fluorescent whitening agent, UV absorbers, light stabilizers, matting agents, coloring pigments,
Dyes and the like can be mentioned. In particular, when a coloring pigment or dye is blended, generally even very slight dispersion spots are easily detected as colored spots, but according to the method of the present invention, the liquid modifier is very easily dispersed uniformly in the polyester. It is particularly preferable because it is possible.

Examples of pigments or dyes preferably used include organic pigments such as azo, phthalocyanine, quinacridone, anthraquinone, dioxazine, perylene / perinone, iron oxide, titanium oxide, ultramarine, carbon black and the like. And azo, anthraquinone, perylene, phthalocyanine, and heterocyclic dyes.These may be used alone or in combination, or in combination with pigment and dye. You may.

[0011] The proportion of the function-imparting agent in the liquid dispersion medium varies depending on the type of agent used and the degree of modification of the polyester.
It is preferably 0.1 to 100 parts by weight based on parts by weight. If the amount is less than 0.1 part by weight, the amount of the liquid modifier required for modifying the polyester increases, and the mechanical properties and the like of the obtained fiber are undesirably reduced. On the other hand, if it exceeds 100 parts by weight, it becomes difficult to disperse the liquid modifier in the polyester, and it is not preferable because fibers of uniform quality cannot be obtained.

In the present invention, when the above-mentioned function-imparting agent is added to the liquid dispersion medium, the aromatic monocarbodiimide is further added to the dispersion medium (liquid polyester) in an amount of 1 to 20 parts by weight, preferably 1 to 10 parts by weight. It is important to mix parts by weight. If the compounding amount is less than 1 part by weight, the mechanical properties of the obtained fiber and the kneading property of the fiber will deteriorate, and the condition of the yarn-making process will deteriorate. On the other hand, when the amount exceeds 20 parts by weight, it is not preferable because coloring of the obtained fiber is promoted and heat resistance is deteriorated.

The aromatic monocarbodiimide used here includes, for example, 2,2'-dimethyldiphenylcarbodiimide, 2,2'-diisopropylcarbodiimide, 2,2'-diethoxydiphenylcarbodiimide,
2,6,2 ', 6'-tetraisopropyldiphenylcarbodiimide, 2,4,6,2', 4 ', 6'-hexaisopropyldiphenylcarbodiimide, and the like, and especially 2,6,2', 6 '-Tetraisopropyldiphenylcarbodiimide has good heat resistance and hardly generates decomposition gas at the time of spinning, and the detailed reason is unknown, but the viscosity of the liquid modifier obtained when blended with the liquid dispersion medium is increased. Even if the amount of the function-imparting agent in the liquid modifier is increased, the dispersion in the polyester melt becomes easy, and the modified polyester fiber having good mechanical properties and little unevenness in quality is stable. It is not preferred because it has the characteristic of being obtained.

The viscosity of the liquid modifier containing the function-imparting agent and the aromatic monocarbodiimide is 2,000 poise or less at room temperature, preferably 1500 poise, depending on the handleability and the measuring accuracy when adding and mixing into the molten polyester. It is desirable to be less than poise. When it exceeds 2,000 poise, not only does the flowability decrease, the handleability deteriorates, but also the weighing accuracy decreases, and quality unevenness tends to occur.

The method for 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 three-roll mill can be used, and these can be used in combination. Also, the order of mixing is not particularly limited, and the function-imparting agent and the carbodiimide may be mixed simultaneously or separately. Above all, it is preferable to mix the carbodiimide first because the viscosity of the mixture is reduced and the kneading of the function-imparting agent is often facilitated.

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

It is not necessary to employ any 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 metered by a gear pump or the like. Mixing using a static mixer or the like, and then discharging from a spinneret. Here, the addition amount of the liquid modifier varies depending on the amount of the function-imparting agent incorporated in the liquid modifier and the required degree of modification, but usually 100 parts by weight of the molten polyester. Is preferably 1 to 11 parts by weight with respect to

When the amount of the liquid modifier to be added is less than 1 part by weight with respect to 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, when it exceeds 11 parts by weight, the mechanical properties of the obtained fiber are often deteriorated and the yarn-making process is often failed.

The polymer discharged from the spinneret may be drawn according to a conventional method, for example, at a drawing speed of 1000 m / min, and then stretched at a magnification capable of obtaining a desired elongation.

[0020]

The reason why the above-described production method of the present invention can stably provide a modified polyester fiber having good mechanical properties and no unevenness in quality has not been elucidated in detail. It is estimated as follows. That is,
The aromatic monocarbodiimide used in the present invention blocks the liquid polyester dispersion medium and the molecular chain terminal functional groups of the polyester, so that the thermal decomposition of the dispersion medium and the reaction between the dispersion medium and the polyester are suppressed. Also, in order to increase the degree of polymerization by partially bonding 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 is improved even if the amount of the functionalizing agent is increased. as a result,
Problems such as reduced mechanical properties of the fibers due to thermal decomposition and thermal reaction of the dispersion medium and yarn breakage during yarn reduction are reduced, and problems such as uneven quality due to dispersion of the functionalizing agent and reduced yarn production stability are also encountered. It will decrease.

[0021]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In addition, each characteristic value in an Example was measured by the following method.

(Strong elongation) Using an Instron type tensile tester, a sample length of 25 cm and a tensile speed of 30 cm / mi
n.

(Quality unevenness) The drawn yarn is knitted on a sock knitted fabric,
The drawn yarn of the reference color was visually compared with a knitted yarn in the same manner, and a yarn having a distinct color difference was defined as a quality plaque and expressed as a ratio of the quality plaque to the total number of visual comparisons.

(Light fastness) A colored polyester fiber is made into 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 determined by gray scale (grade).

(Spun yarn breakage rate) The yarn was spun at a winding speed of 1100 m / min and expressed as the number of yarn breaks per winding length of 10 ⁶ m.

(Stretched Thread Breakage Rate) Stretching was performed at a stretching speed of 1000 m / min and expressed as the number of times of thread breakage per 3 × 10 ⁵ m of the drawn yarn length.

[0027]

Example 1 5 parts by weight of carbodiimide was added to 100 parts by weight of the liquid polyester shown in Table 1, then 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 0.6 melted by heating at 290 ° C.
In polyethylene terephthalate No. 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. Thereafter, it was extruded from a spinneret having 24 discharge holes at a discharge rate of 30 g / min and wound at a speed of 1100 m / min. The obtained undrawn yarn is 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 little modification unevenness, and the process condition during the yarn production was good.

[0030]

Examples 2 to 9 and Comparative Examples 1 to 4 A liquid modifier was obtained in the same manner as in Example 1 except that the liquid polyester and the function-imparting agent were changed to those shown in Table 1.

The obtained liquid modifier was added to and mixed with molten polyethylene terephthalate in the same manner as in Example 1, followed by spinning to obtain a modified polyester fiber. The results are summarized in Table 1.

[0032]

[Table 1]

In the table, dispersant A is a polypropylene sebacate having an average molecular weight of 8000, an acid value of 2 mg KOH / g and a hydroxyl value of 15 mg KOH / g, and dispersant B is an average molecular weight of 400.
0, acid value 1.5 mg KOH / g, hydroxyl value 12 mg KO
H / g polypropylene sebacate, dispersant C
―Bis (4- (β-palmitoxyethoxy) phenyl)
Represents propane, and monocarbodiimide (a) is 2,
6,2 ', 6'-tetraisopropyldiphenylcarbodiimide and monocarbodiimide (b) represent 2,2'-dimethyldiphenylcarbodiimide, and the functionalizing agent a is 8 parts by weight of phthalocyanine blue, 2 parts by weight of quinacridone red, The mixed blue pigment of 0.2 parts by weight of carbon black and the function-imparting agent b were added to the above-mentioned blue pigment as an ultraviolet absorber, 2 parts by weight of Tinuvin 320 manufactured by Ciba-Geigy, and a light stabilizer, Chimassorb 994 manufactured by Ciba-Geigy
2 parts by weight are mixed.

[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, and the modified polyester has excellent mechanical properties and little unevenness in quality. Fibers can be produced very stably.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI D01F 1/10 D01F 1/10 (56) References JP-A-6-341017 (JP, A) JP-A-3-104919 (JP, A) JP-A-58-132115 (JP, A) JP-A-2-264069 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6/92 301-309 C08K 5/3415 C08L 67/02 D01F 1/00-1/10

Claims (3)

(57) [Claims] 1. In a polyester melt, 100 parts by weight of a liquid polyester dispersion medium which is liquid at room temperature is
A pigment, a dye, an antibacterial agent, 0.1 to 100 parts by weight of a functionalizing agent such as an ultraviolet absorber, and 1 to 20 parts by weight of an aromatic monocarbodiimide are added and mixed with a liquid modifier. A method for producing a modified polyester fiber, comprising spinning. 2. The method for producing a modified polyester fiber according to claim 1, wherein the amount of the liquid modifier is 1 to 11 parts by weight based on 100 parts by weight of the polyester melt. 3. The method according to claim 1, wherein the aromatic monocarbodiimide is 2,6,6.
The method for producing a modified polyester fiber according to claim 1, wherein the modified polyester fiber is 2 ', 6'-tetraisopropyldiphenylcarbodiimide.