JPH038377B2 - - Google Patents

Description

[Detailed description of the invention]

a Field of Application The present invention relates to a method for producing polyester. More specifically, particle dispersibility is improved, and when made into a film, it has excellent transparency and slipperiness, and when made into a fiber and subjected to alkali weight loss, extremely fine irregularities are formed on the fiber surface, making it excellent when dyed. The present invention relates to a method for producing polyester that exhibits color depth and clarity and is suitable for use in producing fibers or films. b. Prior Art Polyester has many excellent properties and is therefore widely used as fibers and films.
However, compared to natural fibers such as wool and silk, cellulose fibers such as rayon and acetate, and acrylic fibers, polyester fibers lack the depth of color and are inferior in color development and clarity when colored. There is. Conventional methods for improving the color, which is a drawback of polyester fibers, include (1) forming a transparent thin film of low refractive index resin on the surface of polyester fibers, and (2) applying 80 to 500 mA sec/cm ² to the surface of woven or knitted fabrics. (3) A method of forming fine irregularities on the fiber surface by applying plasma irradiation. (3) A method of forming specific surface irregularities on the fiber surface by subjecting a fiber made of polyester containing inorganic fine particles such as silica with a particle size of 80 mμ or less to an alkali reduction treatment. Methods for imparting structure are known. However, although method (1) above prevents the reflection of light on the fiber surface and can certainly improve the color, the transparent thin film formed on the fiber surface easily falls off when washed, etc. , its durability is insufficient. In method (2) above, the plasma discharge equipment is expensive, which increases the cost, and since there is no unevenness on the surface of the fiber in the part of the fiber that is in the shadow of the irradiated surface, there is a risk of thread formation within the fiber structure that occurs during wear. There is a drawback that the smooth fiber surface comes to the surface due to falls etc., resulting in color spots. Furthermore, in the method (3) above, since the fiber surface is roughened, reflection of light is prevented and a certain degree of color improvement effect can be expected. However, even with this method, the color improvement effect is insufficient, and in addition, perhaps due to the extremely complicated shape of the unevenness, the unevenness is destroyed by external physical effects such as friction, and the destroyed part is left behind. There are drawbacks such as large discoloration or difference in gloss compared to the undestructed portion, and furthermore, easy fibrillation. c. Purpose of the Invention The present inventor aims to provide a polyester fiber that does not have the above-mentioned drawbacks and has excellent color depth and clarity by adding micropores to the polyester fiber. As a result of intensive studies on the fiber surface uneven structure and color improvement effect of alkali treatment of fibers, we found that in conventional methods, the average primary particle size of inert inorganic fine particles blended into polyester exceeds 100 mμ, or the average primary particle size When inert inorganic fine particles with a size of 100 mμ or less are used, secondary agglomeration easily occurs when they are blended with polyester, resulting in the presence of a large number of secondary agglomerated particles with a size exceeding 100 mμ. In either case, inside the polyester fiber
Due to the presence of particles with a size exceeding 100 mμ,
It was discovered that alkali treatment forms irregularities on the fiber surface, mainly in the visible light wavelength range or on the order of more than that, which makes the color improvement effect insufficient and makes the fibrillation resistance inferior. . Based on this knowledge, the present inventor conducted various studies on methods for suppressing secondary aggregation of inert inorganic fine particles with an average primary particle size of 100 mμ or less.
By using a class phosphonium compound together with
It was found that the formation of secondary agglomerated particles of 100 mμ or more is suppressed. By treating the fibers obtained from the polyester with improved particle dispersibility with alkali, it is possible to finally obtain polyester fibers having irregularities that are smaller than the wavelength of visible light evenly over the entire surface of the fibers. found that the depth and vividness of the color when dyed was improved, as well as the fibril resistance. In addition, since the polyester obtained by the above method has improved particle dispersibility, it can be made into a film with excellent transparency and slipperiness.
For magnetic tapes such as audio, video, and computers, for magnetic recording media such as floppy disks, for photographs, for graphic arts, for stamping wheels, for decorative threads such as gold and silver threads, and for electrical materials such as capacitors. It was found that it is also extremely useful as a raw material for films such as. The present invention was completed as a result of further studies based on these findings. d. Constitution of the Invention That is, the present invention involves producing a polyester by reacting a difunctional carboxylic acid, mainly terephthalic acid, or an ester-forming derivative thereof with at least one type of alkylene glycol, and the production reaction is completed. (a) at least one selected from silica, alumina, titanium oxide and calcium carbonate having an average primary particle size of 100 mμ or less in an amount of 0.1 to 10% by weight based on the resulting polyester; a kind of inert inorganic fine particles and (b) 0.001 to the difunctional carboxylic acid component.
This is a method for producing polyester characterized by adding and blending 0.5 mol% of a quaternary phosphonium compound. The polyester used in the present invention is a polyester having terephthalic acid as the main acid component and at least one glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol as the main glycol component. The main target is It may also be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/or a part of the glycol component is replaced with the above-mentioned glycol or other diol component other than the main component. It may also be polyester. Examples of difunctional carboxylic acids other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid,
Diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, 5-
Examples include aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as sodium sulfoisophthalic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. Among them, the above 5-
In a cationic dye-dyeable polyester made by copolymerizing an isophthalic acid component having an alkali metal sulfonate group such as sodium sulfoisophthalic acid with 1 to 7 mol% of terephthalic acid, the final polyester fiber has a rough surface structure. Therefore, the effect of applying the method of the present invention is particularly large. Examples of diol compounds other than the above-mentioned glycols include aliphatic, alicyclic, and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S, and polyoxyalkylene glycols. etc. can be given. Furthermore, polycarboxylic acids such as trimellitic acid and pyromellitic acid, polyols such as glycerin, trimethylolpropane, and pentaerythol can be used as long as the polyester is substantially linear. Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, usually terephthalic acid and ethylene glycol are directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene glycol are transesterified. The first stage reaction is to react with terephthalic acid to produce a glycol ester and/or its low polymer, and the first stage reaction product is heated under reduced pressure until the desired degree of polymerization is achieved. It is produced by a second step of polycondensation reaction. The inert inorganic fine particles used in the present invention are particles that do not inhibit the polyester production reaction and do not cause extreme coloring during polyester production.
These are inorganic fine particles that are substantially insoluble in polyester. In the present invention, at least one kind of fine particles selected from silica, alumina, titanium oxide, and calcium carbonate is used as such inert inorganic fine particles. Examples of silica include silica sol (so-called colloidal silica), dry method Preferred examples include silica, dry process silica containing aluminum oxide, dry process silica having an alkyl group on the particle surface and blocking silanol groups on the particle surface, and as the alumina, alumina sol (so-called colloidal alumina). Preferred examples include finely particulate alumina, etc., ultrafine titanium oxide as the titanium oxide, and calcium carbonate sol and finely particulate calcium carbonate as the calcium carbonate. In the present invention, the average primary particle diameter of the inert inorganic fine particles is 100 mμ or less, preferably 50 mμ
It is as follows. If the average primary particle size exceeds 100 mμ, the color improvement effect and fibrillation resistance of the final polyester fiber will decrease, and the transparency of the film will become insufficient. The amount of such inert inorganic fine particles added is in the range of 0.1 to 10% by weight based on the polyester to be produced,
Particularly preferred is a range of 0.1 to 4% by weight. 0.1% by weight
If the amount is less than 10% by weight, the color depth and clarity of the final polyester fiber and the slipperiness of the film will be insufficient, and if the amount exceeds 10% by weight, the transparency and abrasion resistance of the final fiber or film will be insufficient. Sexuality begins to decline. The inert inorganic fine particles described above are preferably added as a dispersion slurry or sol of glycol, alcohol, water, or the like. For example, to explain silica sol, (1) aqueous silica sol obtained by removing alkali from water glass is used as is, (2) glycol and/or alcohol is mixed with this aqueous silica sol, and (3) this aqueous silica sol is It is desirable to replace the water with glycol and/or alcohol and add the glycol and/or alcohol at any stage until the polyester production reaction is completed. In the present invention, the fourth terminal phosphonium compound used in combination with the inert inorganic fine particles has the following general formula: A quaternary phosphonium compound represented by is preferably used. In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or a substituted derivative thereof, and R ₃ and R ₄ may form a ring. . X is an anionic residue, among which are halides, hydroxides, hydrosulfates, alkyl sulfates, alkyl ether sulfates, alkyl sulfonates, alkylbenzene sulfonates, acetates,
Anionic residues of fatty acid salts are preferred. Preferred specific examples of such quaternary phosphonium compounds include tetramethylphosphonium chloride, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetraisopropylphosphonium chloride, and tetrabutyl. Phosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, tetrabutylphosphonium hydroxide, butyltriphenylphosphonium chloride, ethyltrioctylphosphonium chloride, hexadecyltributylphosphonium chloride, ethyltrihexylphosphonium chloride, cyclohexyltributylphosphonium chloride, benzyl Tributylphosphonium chloride, tetraphenylphosphonium chloride, tetraphenylphosphonium chloride, tetraphenylphosphonium hydroxide, octyltrimethylphosphonium chloride, octyldimethylbenzylphosphonium chloride, lauryldimethylbenzylphosphonium chloride, lauryldimethylbenzylphosphonium hydroxide, stearyltrimethylphosphonium Chloride, lauryltrimethylphosphonium ethosulfate, laurylbenzenetrimethylphosphonium methosulfate, lauryldimethyl-o-chlorobenzylphosphonium chloride, stearyl ethyldihydroxyethylphosphonium ethosulfate, tetraethylphosphonium acetate, tetraethylphosphonium dodecylbenzene sulfonate, tetraethylphosphonium stearate , tetraethylphosphonium oleate, and the like. If the amount of the quaternary phosphonium compound is too small, the effect of improving the dispersibility of the inert inorganic fine particles in the polyester will be insufficient, and as the amount is increased, the particle dispersibility will improve.
If the amount is too large, the particle dispersibility will no longer be significantly improved, and the polymer will instead be colored yellow. For this reason, the amount of the quaternary phosphonium compound is determined based on the bifunctional carboxylic acid component.
Should be in the range 0.001-0.5 mol%, especially
A range of 0.01 to 0.3 mol% is preferred. The quaternary phosphonium compound may be added at any stage until the production of the polyester described above is completed; for example, it may be added and mixed into the raw material of the polyester, or it may be added during the first stage reaction. It may be added between the end of the first stage reaction and the start of the second stage reaction, or it may be added during the second stage reaction. Among the above-mentioned quaternary phosphonium compounds, there are those that have the ability to catalyze the transesterification reaction when the first step reaction is an esterification reaction, and those that have the ability to suppress ether formation when the first step reaction is the esterification reaction. There are compounds that have the ability to catalyze the second-stage reaction, and when using such compounds, it is not necessary to use a separate catalyst or ether formation inhibitor. It can also be added before or during the first step of the reaction to serve as a catalyst and an ether formation inhibitor. The above-mentioned quaternary phosphonium compound can also be added by being dissolved and mixed into the dispersion slurry or sol of the above-mentioned inert inorganic fine particles, and this is preferable from the viewpoint of particle dispersibility. e Effects of the invention As explained above, in the present invention, (a) a specific amount of inert inorganic fine particles having an average primary particle diameter of 100 mμ or less, and (b) a quaternary phosphonium compound are added. By completing the production of the polyester after that, an inert fine particle-containing polyester with improved particle dispersibility is obtained, and after being made into fibers, an alkali weight reduction treatment is performed to improve fineness and compactness. It is possible to provide polyester fibers with an improved surface unevenness structure, improved color depth, clarity, and friction durability, and a polyester film with improved transparency and slipperiness when formed. can be given. Note that the polyester obtained by the method of the present invention may contain optional additives, such as catalysts, color inhibitors, heat resistant agents, flame retardants, optical brighteners,
A matting agent, a coloring agent, etc. may also be included. f Examples The following examples will be further explained. Parts and % in Examples indicate parts by weight and % by weight, and the particle dispersibility of the resulting polyester, the depth of color when dyeing polyester fibers, and resistance to friction discoloration were measured by the following methods. (i) Particle dispersibility Orthochlorophenol solution of polyester containing inert inorganic fine particles (solution concentration: 2 g/20
ml, dissolution temperature 160℃, dissolution time: 60 minutes), and check the turbidity of this solution using SEP-
Measured using an H-type HTR meter. The greater the number of secondary aggregated particles, the greater the turbidity value. (ii) Depth of color As a measure of the depth of color, bathochromicity (K/
S) was used. This value was determined by measuring the spectral reflectance (R) of the sample fabric using a Shimadzu RC-330 self-recording spectrophotometer.
−Munk). The larger this value is, the greater the deep color effect is. K/S=(1-R) ² /2R (measurement wavelength 500 mμ) In addition, K shows an absorption coefficient and S shows a scattering coefficient. (iii) Resistance to friction discoloration Using a Gakushin type flat abrasion machine for friction fastness testing, the test cloth was abraded a specified number of times under a load of 500 g using a 100% polyethylene terephthalate dioset as the friction cloth. hand,
The degree of discoloration was determined using a gray scale for discoloration. The case where the wear resistance was extremely low was rated as 1st grade, and the case where it was extremely high was rated as 5th grade. Example 1 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, and 0.06 parts of calcium acetate monohydrate (0.066 mol% relative to dimethyl terephthalate) were charged into a transesterification tank, and heated from 140°C over 4 hours under a nitrogen gas atmosphere. The transesterification reaction was carried out while raising the temperature to 230°C and distilling the generated methanol out of the system. Subsequently, 0.05 part of trimethyl phosphate (relative to dimethyl terephthalate) was added to the resulting reaction product.
0.069 mol %) and 0.04 parts of antimony trioxide (0.027 mol % relative to dimethyl terephthalate) and an average primary particle size of 20 mμ (ethylene glycol medium, concentration 10%).
A mixture obtained by dissolving tetraphenylphosphonium chloride in the amount shown in Table 1 was added in an amount of 1.0% as silicon oxide based on the obtained polyester, and the mixture was transferred to a polymerization vessel. Next, the pressure was reduced from 760 mmHg to 1 mmHg over 1 hour, and at the same time the temperature was raised from 230°C to 285°C over 1 hour and 30 minutes.
Polymerization was carried out for an additional 3 hours at a polymerization temperature of 285℃ under reduced pressure of 1 mmHg or less, for a total of 4 hours and 30 minutes, and the intrinsic viscosity was 0.636 ~
0.643 and a softening point of 261-262°C was obtained. The particle dispersibility of the obtained polymer was as shown in Table 1. This polymer was dried using a conventional method, and the pore size was 0.3 mm.
Using a spinneret with 36 circular spinning holes,
It was melt-spun at 290° C. and then drawn at a draw ratio of 3.5 times according to a conventional method to obtain 75 denier/36 filament atoms. The obtained yarn was strongly twisted with an S twist of 2500 T/m and a Z twist of 2500 T/m, and then the highly twisted yarn was steamed at 80° C. for 30 minutes to stop twisting. The warp density is 47 threads/cm and the weft density is 32 threads/cm.
A pear-skinned jersey fabric was woven with two S and Z twists arranged alternately. The obtained gray fabric was relaxed in a rotary washer at boiling temperature for 20 minutes,
After graining and presetting in a conventional manner, it is treated with a 3.5% sodium hydroxide aqueous solution at boiling temperature.
A fabric with a weight loss rate of 20% was obtained. Dianix Black HGFS fabric after alkali treatment
(Mitsubishi Chemical Industries, Ltd. product) After dyeing with 15% owf at 130°C for 60 minutes, dye with an aqueous solution containing 1 g of sodium hydroxide and 1 g of hydrosulfite at 70°C for 20 minutes.
A black dyed cloth was obtained by reduction washing for a minute. Table 1 shows the color depth and friction discoloration resistance of the obtained black cloth after 200 abrasions. Example 2 Aluminum oxide was used instead of the silica sol mixture used as the inert inorganic fine particles in Example 1.
A mixture obtained by dissolving the amount of tetraphenylphosphonium chloride listed in Table 1 in a 10% ethylene glycol slurry of dry process silica containing 1.0% and having an average primary particle size of 15 mμ was added to the resulting polyester. 1.0% as silicon oxide
The same procedure as in Example 1 was carried out except that the addition amount was as follows. The results are shown in Table 1. Example 3 Example except that 0.06 parts of tetra-n-butylphosphonium chloride (0.04 mol % based on dimethyl terephthalate) was used in place of the tetraphenylphosphonium chloride used as the quaternary phosphonium compound in Example 1. It was done in the same way as 1. The results were as shown in Table 1. Example 4 0.12 parts of tetraethylphosphonium bromide (0.1 mol % based on dimethyl terephthalate) was used in place of the tetraphenylphosphonium chloride used as the quaternary phosphonium compound in Example 1.
The same procedure as in Example 1 was carried out except that . The results are shown in Table 1. Example 5 The tetraphenylphosphonium chloride used as the quaternary phosphonium compound in Example 1 was replaced with 0.03 parts of n-butyltriphenylphosphonium iodide (0.013 mol % based on dimethyl terephthalate). The same procedure as in Example 1 was carried out, and the results shown in Table 1 were obtained. Example 6 Example except that 0.367 parts of tetraphenylphosphonium hydroxide (0.2 mol % based on dimethyl terephthalate) was used in place of the tetraphenylphosphonium chloride used as the quaternary phosphonium compound in Example 1. The same procedure as in 1 was carried out, and the results shown in Table 1 were obtained. Example 7 100 parts of dimethyl terephthalate, 66 parts of ethylene glycol, 4 parts of sodium 3,5-di(carbomethoxy)benzenesulfonate (2.6 mol% based on dimethyl terephthalate), manganese acetate tetrahydrate
0.03 part and 0.1 part of sodium acetate trihydrate as an ether production inhibitor were charged into a transesterification tank, and the temperature was raised from 140°C to 230°C over 4 hours under a nitrogen gas atmosphere, and the methanol produced was distilled out of the system. The transesterification reaction was carried out. Subsequently, 0.03 parts of a 56% aqueous solution of orthophosphoric acid and 0.04 parts of antimony trioxide were added to the obtained product, and the mixture was further added to silica sol (ethylene glycol medium, concentration 10%) with an average primary particle size of 20 mμ as shown in Table 2. A mixture obtained by dissolving the amount of tetraphenylphosphonium chloride described in 1. was added in an amount of 1.0% as silicon oxide based on the polyester obtained, and the mixture was transferred to a polymerization vessel. Then from 760mmHg to 1mmHg over 1 hour
At the same time, reduce the pressure to 230℃ over 1 hour and 30 minutes.
The temperature was raised to 280℃. Polymerization was carried out for an additional 2 hours at a polymerization temperature of 280°C under reduced pressure of 1 mmHg or less, for a total of 3 hours and 30 minutes.
A polymer having an intrinsic viscosity of 0.502 to 0.506 and a softening point of 256 to 257°C was obtained. The particle dispersibility of the obtained polymer was as shown in Table 2. Using this polymer, a satin-textured dioset fabric having a weight loss rate of 10% was obtained by spinning, drawing, hard twisting, twisting, weaving, embossing, presetting, and alkali treatment in the same manner as in Example 1. After this alkali treatment, the fabric was dyed at 120°C for 60 minutes at 120°C in a dye bath containing 8% owf of Aizen Cathilon Black CD-GLH (Hodogaya Chemical Co., Ltd. product) containing 2 g of Glauber's salt, and then soaped according to a conventional method. A black cloth was obtained. The depth of color and resistance to friction discoloration after 200 abrasions of the obtained black dyed fabric were as shown in Table 2. Example 8 Aluminum oxide was used instead of the silica sol mixture used as the inert inorganic fine particles in Example 7.
A mixture obtained by dissolving tetraphenylphosphonium hydroxide in the amount listed in Table 1 in a 10% ethylene glycol slurry of dry process silica containing 1.0% and having an average primary particle size of 15 mμ was added to the resulting polyester. The same procedure as in Example 7 was conducted except that silicon oxide was added in an amount of 1.0%. The results were as shown in Table 2. Example 9 Instead of the silica sol mixture used as the inert inorganic fine particles in Example 1, a mixture with an average primary particle size of
A mixture obtained by dissolving the amount of tetraphenylphosphonium chloride listed in Table 3 in a 10% ethylene glycol slurry of 10 mμ fine-grained alumina was added to the resulting polyester so that the amount of aluminum oxide was 1.0%. The same procedure as in Example 1 was carried out except for the following. The results are shown in Table 3. Example 10 Instead of the silica sol mixture used as the inert inorganic fine particles in Example 1, a mixture with an average primary particle size of
A mixture obtained by dissolving the amount of tetraphenylphosphonium chloride listed in Table 3 in a 10% ethylene glycol slurry of 20 mμ ultrafine titanium oxide was added to the resulting polyester so that the amount of titanium oxide was 1.0%. The same procedure as in Example 1 was carried out except for the addition. The results are shown in Table 3. Example 11 Instead of the silica sol mixture used as the inert inorganic fine particles in Example 1, a mixture with an average primary particle size of
A mixture obtained by dissolving 18 mμ of calcium carbonate sol (ethylene glycol medium, concentration 10%) in the amount of tetraphenylphosphonium hydroxide listed in Table 3 was added to give a concentration of 1.0% calcium carbonate based on the resulting polyester. The results are shown in Table 3.

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Claims (1)

[Scope of Claims] 1. In producing a polyester by reacting a difunctional carboxylic acid, mainly terephthalic acid, or an ester-forming derivative thereof with at least one alkylene glycol, the process up to the completion of the production reaction At any stage, (a) at least one member selected from silica, alumina, titanium oxide, and calcium carbonate having an average primary particle size of 100 mμ or less in an amount of 0.1 to 10% by weight based on the obtained polyester; of inert inorganic fine particles and (b) 0.001 to the difunctional carboxylic acid component.
A method for producing polyester, which comprises adding and blending 0.5 mol% of a quaternary phosphonium compound. 2. The method for producing polyester according to claim 1, wherein the inert inorganic fine particles are colloidal silica. 3. The method for producing polyester according to claim 1, wherein the inert inorganic fine particles are dry process silica. 4. The method for producing a polyester according to any one of claims 1 to 3, wherein 1 to 7 mol% of the difunctional carboxylic acid is isophthalic acid containing an alkali metal sulfonate group.