JPH0330617B2 - - 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 reduction, 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 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 to improve 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, (2) applying 80 to 500 mA sec/cm (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 fibers made of polyester containing inorganic fine particles such as silica with a particle size of 80 mμ or less to alkali weight 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 colored 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 aggregation 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, since particles with a size exceeding 100 mμ exist inside the polyester fiber, the alkali treatment mainly forms irregularities in the visible light wavelength range or larger on the fiber surface, resulting in color improvement effects. It was found that this resulted in insufficient fibrillation resistance and poor fibril resistance. Based on this knowledge, the present inventors investigated various methods for suppressing secondary aggregation of inert inorganic fine particles with an average primary particle diameter of 100 mμ or less, and found that by using a compound containing an inorganic ammonium ion in combination. It was found that the formation of secondary agglomerated particles of 100 mμ or more was 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. ,
It has been found that the depth and vividness of the color when dyed is improved, as well as the fibril resistance is improved. 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 also found that it is 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 bifunctional carboxylic acid, mainly terephthalic acid, or an ester-forming derivative thereof with at least one kind of alkylene glycol. (a) an amount 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; at least one inert inorganic fine particle and (b) 0.001 to the difunctional carboxylic acid component.
This method of producing polyester is characterized by adding and blending 0.5 mol% of an ammonium compound represented by the following general formula [NH ₄ ] ⁺ A ^- (where A represents an anion residue). The polyester in the present invention is a polyester having terephthalic acid as the main acid component and at least one type of 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,
Diphenoxyethine dicarboxylic 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. Further, within the range where the polyester is substantially linear, polycarboxylic acids such as trimellitic acid and pyromellitic acid, glycerin, trimethylolpropane,
Polyols such as pentaerythritol can be used. Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, it is usually a direct esterification reaction between terephthalic acid and ethylene glycol, a transesterification reaction between a lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol, or a transesterification reaction between terephthalic acid and ethylene glycol. 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.
They are inorganic fine particles selected from silica, alumina, titanium oxide, and calcium carbonate and are substantially inert to polyester. Examples of such inert inorganic fine particles include silica sol (so-called colloidal silica), dry process 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. Preferred examples include alumina sol (so-called colloidal alumina), finely divided alumina, ultrafine titanium oxide, calcium carbonate sol, and finely divided 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 or less. If the average primary particle diameter 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, particularly preferably in the range of 0.1 to 4% by weight, based on the polyester to be produced. If the amount is less than 0.1% 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 of the final fiber or film will be insufficient. Friction resistance durability begins to decline. The above-mentioned inert inorganic particles are preferably added as a dispersed slurry or sol of glycol, alcohol, water, or the like. For example, to explain silica sol, (1) the aqueous silica sol obtained by removing alkali from water glass is used as it is, (2) this aqueous silica sol is mixed with glycol and/or alcohol, 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 ammonium compound used in combination with the inert inorganic fine particles is a compound having an inorganic ammonium ion represented by the following general formula [NH ₄ ] ⁺ A ^- . In the formula, A is an anionic residue,
Contains organic and inorganic anionic residues, such as anionic residues of organic carboxylates such as acetate, oxalate, benzoate, phthalate, stearate, etc.; Anionic residues of inorganic acid salts such as sulfates, bisulfites, phosphates, carbonates, bicarbonates, thiocyanates, etc., halides, hydroxides, hydrosulfates, alkyl sulfates such as chlorides, etc. Examples include anionic residues of ate, alkyl ether sulfate, alkyl sulfonate, alkylbenzene sulfonate, and tosylate. Preferred specific examples of such ammonium compounds include ammonium acetate, ammonium oxalate, ammonium carbonate, ammonium bicarbonate, ammonium hydroxide, ammonium chloride, ammonium ethosulfate, ammonium dodecylbenzenesulfonate, and those having an average carbon number of 14. ammonium alkylsulfonate, ammonium p-toluenesulfonate (ammonium tosylate),
Ammonium borate, ammonium chloride, ammonium formate, ammonium amidosulfate, ammonium tartrate, ammonium aminoformate (NH ₂ COONH ₄ ), ammonium 8-anilino-1-naphthalenesulfonate, ammonium carbamate, ammonium citrate, phosphorus Examples include ammonium acid, ammonium hypophosphite, ammonium salicylate, ammonium succinate, ammonium sulfamate, ammonium sulfanilate, and ammonium thioglycolate. If the amount of the ammonium compound blended is too small, the effect of improving the dispersibility of inert inorganic fine particles in polyester will be insufficient.As the amount is increased, the particle dispersibility will improve, but if the amount is too large, the dispersibility of the inert inorganic particles in the polyester will be insufficient. Particle dispersibility did not show any significant improvement, and instead the polymer became colored yellow. Therefore, the amount of ammonium compound to be added is 0.001 to 0.5 with respect to the difunctional carboxylic acid component.
The range should be in the range of mol %, particularly preferably in the range of 0.01 to 0.3 mol %. The ammonium compound may be added at any stage until the production of the polyester described above is completed; for example, the ammonium compound may be added and mixed into the polyester raw materials, added during the first stage reaction, or added at the first stage.
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 ammonium compounds, 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 an esterification reaction. Furthermore, there are compounds that have the ability to catalyze the second-stage reaction, and when such compounds are used, it is not necessary to use a separate catalyst or ether formation inhibitor. Alternatively, it can be added during the reaction to serve as a catalyst and an ether formation inhibitor. The ammonium compound can also be added by being dissolved and mixed into the dispersion slurry or sol of the 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 size of 100 mμ or less, and (b) a compound having an inorganic ammonium ion are added. However, 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 reduction treatment is performed to improve fineness and density. A polyester fiber with an improved surface roughness structure, improved color depth, clarity, and friction durability, and improved transparency and slipperiness when formed into a film. Film can be provided. 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, fluorescent 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 An orthochlorophenol solution (solution concentration: 2 g/20 ml, dissolution temperature: 160°C, dissolution time: 60 minutes) of polyester containing inert inorganic fine particles was prepared, and the turbidity of this solution was measured by Nippon Seimitsu Kogaku Co., Ltd. Manufactured SEP-H type HTR
Measured with a 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) formula. 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 Polyethylene terephthalate was used as the friction cloth using a Gakushin flat abrasion machine for friction fastness testing.
Using 100% dioset, the test fabric was
The surface was abraded a predetermined number of times under a load of g, and the degree of discoloration was determined using a gray scale for discoloration and fading. 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 (0.07 mol % relative to dimethyl terephthalate) and an average primary particle size of 20 mμ (ethylene glycol medium, concentration 10%).
A mixture obtained by dissolving ammonium acetate in the amount shown in Table 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 1 over 1 hour.
Reduce the pressure to mmHg, and at the same time raise the temperature to 230°C over 1 hour and 30 minutes.
The temperature rose from 285°C to 285°C. Under reduced pressure of 1 mmHg or less,
Polymerization was performed at a polymerization temperature of 285°C for an additional 3 hours, for a total of 4 hours and 30 minutes, resulting in an intrinsic viscosity of 0.636-0.643 and a softening point of 261-262°C.
of polymer 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,
The mixture was melt-spun at 290°C and then drawn at a draw ratio of 3.5 times according to a conventional method to obtain a raw yarn of 75 denier/36 filaments. The obtained raw yarn was subjected to strong twisting of 2500 T/m for S twist and 2500 T/m for Z twist, and then the highly twisted yarn was steam-treated 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, dyeing with an aqueous solution containing 1 g/l of sodium hydroxide and 1 g/l 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 In Example 1, aluminum oxide was used as the inert inorganic fine particles in place of the silica sol mixture.
% and has an average primary particle size of 15 mμ in a 10% ethylene glycol slurry.
The same procedure as in Example 1 was carried out, except that a mixture obtained by dissolving ammonium acetate in the amount shown in the table was added so that the amount of silicon oxide was 1.0% based on the resulting polyester. The results are shown in Table 1. Example 3 The same procedure as in Example 1 was carried out, except that 0.016 part of ammonium bicarbonate (0.04 mol % based on dimethyl terephthalate) was used in place of ammonium acetate used as the ammonium compound in Example 1. The results were as shown in Table 1. Example 4 0.072 parts of 25% NH ₄ OH in place of ammonium acetate used as the ammonium compound in Example 1
The same procedure as in Example 1 was carried out except that an aqueous solution (0.1 mol % based on dimethyl terephthalate) was used. The results are shown in Table 1. Example 5 In place of ammonium acetate used as the ammonium compound in Example 1, 0.0078 parts of ammonium carbonate monohydrate (based on dimethyl terephthalate) was added.
The same procedure as in Example 1 was carried out except that 0.013 mol %) was used, and the results shown in Table 1 were obtained. Example 6 The same procedure as in Example 1 was carried out, except that 0.055 parts of ammonium chloride (0.2 mol % based on dimethyl terephthalate) was used in place of ammonium acetate used as the ammonium compound in Example 1.
The results as listed 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 part of a 56% aqueous solution of orthophosphoric acid and 0.04 part 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 ammonium acetate described in 1. was added in an amount of 1.0% as silicon oxide based on the resulting polyester, and 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 pressure was reduced to 1 mmHg.
The temperature was raised from 230°C to 280°C over 30 minutes. 1
Polymerization was carried out for an additional 2 hours at a polymerization temperature of 280℃ under reduced pressure below mmHg, for a total of 3 hours and 30 minutes, and the intrinsic viscosity was 0.502~
0.506 and a softening point of 256-257°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 color depth and friction discoloration resistance of the obtained black dyed fabric after 200 abrasions 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 ammonium carbonate monohydrate 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 carried out except that an amount of 1.0% silicon oxide was added. The result is second
It was as shown in the table. Comparative Example 1 The same procedure as in Example 1 was carried out except that in place of the ammonium acetate used in Example 1, tetraethylammonium hydroxide was used in the amount listed in Table 3. The results were as shown in Table 3. Comparative Example 2 The same procedure as in Example 2 was carried out except that in place of the ammonium acetate used in Example 2, tetraethylammonium hydroxide was used in the amount listed in Table 3. The results were as shown in Table 3. Comparative Example 3 The same procedure as in Example 7 was carried out except that in place of the ammonium acetate used in Example 7, tetrabutylammonium chloride was used in the amount listed in Table 3. The results are shown in Table 3. 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 ammonium acetate in the amount listed in Table 4 in a 10% ethylene glycol slurry of 10 mμ fine particulate alumina was added at a concentration of 1.0% as aluminum oxide to the resulting polyester.
The same procedure as in Example 1 was carried out except that the addition amount was %. The results are shown in Table 4. 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
Other than adding a mixture obtained by dissolving ammonium acetate in the amount listed in Table 4 in a 10% ethylene glycol slurry of 20 mμ ultrafine titanium oxide particles so that the titanium oxide amount is 1.0% to the resulting polyester. was carried out in the same manner as in Example 1. The results are shown in Table 4. 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 ammonium acetate in the amount listed in Table 4 in 18 mμ calcium carbonate sol (ethylene glycol medium, concentration 10%) was added as calcium carbonate to the resulting polyester.
The same procedure as in Example 1 was carried out except that the amount was added to 1.0%. The results are shown in Table 4.

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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 (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; one kind 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 an ammonium compound represented by the following general formula: [NH ₄ ] ⁺ A ^- (where A represents an anionic residue). 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.