JPH0718564A - Improver for bleachability - Google Patents

Abstract

(57) [Summary] [Structure] The general formula of the anhydride is xM ₂ O · ySiO ₂ ·
zM ′ O (in the formula, M represents Na and / or K, M ′ represents Ca and / or Mg, and y / x = 0.5 to 4.0,
z / x = 0 to 1.0. ) A bleachability improving agent for a cellulosic fiber represented by the crystalline silicate represented by (4) and / or its hydrate. [Effect] By using the bleaching property improving agent of the present invention, excellent bleaching performance, which was difficult with the conventional bleaching solution, can be obtained.
Even when the hardness of water is particularly high, it is possible to impart excellent texture, whiteness, and sewability as compared with the conventional bleaching method, and at the same time, the eutrophication of rivers and lakes, etc., which has become a problem in recent years, can be achieved. Without promoting it, reduce the use or allow non-use of organic compounds that may have a negative impact on the ecosystem.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a bleaching improver for cellulosic fibers. More specifically, even when the bleaching bath of cellulosic fibers contains a bleaching inhibitor such as a hardness component, it is possible to impart whiteness, texture, and sewability that are higher than conventional ones. The present invention relates to a bleaching property improving agent for cellulosic fibers which can also improve processability.

[0002]

2. Description of the Related Art Generally, since cellulosic fibers still have natural pigments in the fibers even after scouring, removal of the natural pigments and further secondary coloring matters A bleaching operation is performed to do so. The bleaching methods include peroxide bleaching, chlorine bleaching, sodium chlorite bleaching, etc. Among them, peroxide bleaching allows bleaching without damaging the fiber, is easy to operate, and is durable. It is generally widely used because of its whiteness.

This peroxidative bleaching is carried out by utilizing the nascent oxygen generated by the decomposition of hydrogen peroxide to oxidatively decompose the dye in the cellulosic fiber, which is alkaline in pH. Since it is more efficient to perform in the environment of the side, an alkaline agent such as sodium hydroxide is used together. Furthermore, sodium silicate is also used as a stabilizer for the decomposition of hydrogen peroxide under alkali. Therefore, the composition of the bleaching solution is hydrogen peroxide, alkali (sodium hydroxide, etc.), sodium silicate (molar ratio SiO ₂ : N
a ₂ O = 2.5: 1, etc.). When bleaching cellulosic fibers using this, if the hardness of the water used is high, sodium silicate combines with the hardness component of the water to form water-insoluble silicates such as calcium silicate and magnesium silicate, This deposits on the fibers, the whiteness of the fabric is not improved, the texture is coarsely hardened, and the coefficient of friction with the sewing machine needle is increased, which causes a problem in the sewability. Therefore, a solution to this point was desired.

In order to solve this problem, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxylethylenediaminetriacetic acid (HEDTA), and nitrilotriacetic acid (cation) having a cation exchange ability are used. NTA), sodium tripolyphosphate, and specific organic chelating agents (Japanese Patent Publication No. 51-3018).
In some cases, Japanese Patent Publication No. 4 and Japanese Patent Publication No. 51-30185) are used together.

However, in recent years, particularly, phosphates represented by sodium tripolyphosphate, which are effective for improving the above-mentioned properties, have a problem of eutrophication in rivers and lakes, and legal regulations are becoming stronger. That, EDTA, DT
Organic chelating agents such as PA are particularly desired to be improved so that they are not used as much as possible because of their high COD and fear of adverse effects on the ecosystem. Alkali metal silicates typified by sodium silicate have been conventionally used as those having a role of an alkali agent during a bleaching operation, a pH buffering agent, a stain redeposition preventing agent and a stabilizer of a peroxide bleaching agent. Has been done. Furthermore, patent publications relating to the use of alkali metal silicates in industrially used bleaching operations (for example, JP-B-51-30184, JP-B-51-30185, and JP-A-62-321).
95), there is a lot of description about the use of alkali metal silicates (water glasses) as a water-soluble alkali agent, but it is excellent in water resistance and also has crystallinity with cation exchange ability. No description of silicates is found.

[0006]

The inventors of the present invention have made extensive studies in order to solve the above-mentioned problem of poor bleaching of cellulosic fibers. As a result, a crystalline silicate compound having a specific composition has been obtained. Has high alkalinity and cation exchange ability, and its crystalline silicate and / or its hydrate are added to some or all of some of the bleaching agents conventionally used. It was found that the object can be achieved by replacing

That is, the gist of the present invention is xM ₂ O.ySiO ₂ .zM 'O (wherein M represents Na and / or K, M'represents Ca and / or Mg) as a general formula of the anhydride. , Y / x = 0.5 to 4.0, z / x =
It is 0 to 1.0. And a bleaching improver for a cellulosic fiber represented by the crystalline silicate represented by the formula (4) and / or its hydrate.

The crystalline silicate in the present invention has an anhydrous composition represented by the general formula xM ₂ O.ySiO ₂ .zM'O. Here, M represents Na and / or K, and M ′ represents C
a and / or Mg is shown. Further, y / x is 0.5 to 4.
It is 0, preferably 0.5 to 1.9, and more preferably 1.0 to 1.9. If y / x is less than 0.5, the water resistance is insufficient, and if it exceeds 4.0, the ion exchange capacity is low and it is not suitable for use as a bleaching improver. z
/ X is 0 to 1.0, preferably 0.005 to 1.
It is 0, and more preferably 0.01 to 0.6. z / x
When it exceeds 1.0, the ion exchange capacity is low and it is not suitable for use as a bleaching property improving agent. x, y, and z are not particularly limited as long as they have the relationship shown in the above y / x and z / x. K / Na is usually 0 to 8.0 from the viewpoint of increasing the cation exchange rate, and preferably 0.01.
Is ~ 8.0. From the viewpoint of increasing the cation exchange capacity, Mg / Ca is usually 0-10, preferably 0.02-
It is 10.

As the crystalline silicate in the present invention, there are various modes, but preferable examples are as follows. In the above general formula, y /
x = 0.5 to 1.9, z / x = 0.005 to 1.0, M
K / Na in ₂ O = 0.01 to 8.0, Mg in M'O
/ Ca = 0 to 10, the cation exchange capacity is 20
A crystalline silicate that is 0-600 CaCO ₃ mg / g.

The crystalline silicate in the present invention may be a hydrate, and the hydration amount in this case is usually 20 mol% or less in terms of the molar amount of H ₂ O.

The crystalline silicate in the present invention is obtained by synthesis and is composed of three components of M ₂ O, SiO ₂ and M ′ O as shown in the above general formula. Therefore, in order to produce the crystalline silicate in the present invention, a substance corresponding to each component is required as a raw material thereof, but in the present invention, a known compound is appropriately used without particular limitation. For example, as the M ₂ O component and M ′ O component, single or complex oxides, hydroxides, salts of the respective relevant elements, and the element-containing minerals are used. Specifically, for example, as the raw material of the M ₂ O component, NaOH, K
OH, Na ₂ CO ₃ , K ₂ CO ₃ , Na ₂ SO ₄ etc.
As the raw material for the M ′ O component, CaCO ₃ , Ca (OH)
₂ , MgCO ₃ , Mg (OH) ₂ , MgO, dolomite and the like. As the SiO ₂ component, silica stone, silica sand, cristobalite stone, kaolin, talc, fused silica, sodium silicate and the like are used.

In the present invention, these raw material components are mixed in a predetermined quantitative ratio so as to obtain the desired crystalline silicate x, y, z, and usually 300 to 1300 ° C., preferably 5
00-1000 ° C, more preferably 600-900 ° C
Examples of the method include calcination in the range of 1 to crystallize, similarly mixing, and then once melting at 1100 ° C to 1600 ° C to obtain a vitrified product, and then calcining, and further melting and water-vitalizing and calcining. . The heating time is usually 0.1 to 24 hours. Such firing can be usually performed in a heating furnace such as an electric furnace or a gas furnace. Further, after firing, the powder is crushed as necessary to have a predetermined particle size. As the crusher, for example, a ball mill, a roller mill or the like is used. By such a manufacturing method, the crystalline silicate according to the present invention having the above-mentioned structural characteristics can be obtained.

The hydrate of the crystalline silicate according to the present invention can be easily prepared by a known method and is not particularly limited. For example, there may be mentioned a method in which the anhydrous crystalline silicate obtained as described above is suspended in ion-exchanged water to be hydrated, and dried to be powdered.

The crystalline silicate or hydrate thereof according to the present invention thus obtained has at least a cation exchange capacity as a cation exchange capacity from the viewpoint that it is required to have characteristics equal to or higher than those of organic chelating agents generally used. 20
0 CaCO ₃ mg / g or more, preferably 200 to 600
It has CaCO ₃ mg / g. In the present invention, the cation exchange capacity refers to the value of cation exchange capacity obtained by the measuring method described below shown in Examples. However, 50
In the case of 0 CaCO ₃ mg / g or more, it is a value measured with the amount of the calcium chloride solution being 200 ml.

In the present invention, the water resistance means the stability of the crystalline silicate in water. Therefore, inferior water resistance means that the crystalline silicate has poor stability in water and S in water.
i means that the elution amount is increased. On the other hand, “excellent in water resistance” means that the crystalline silicate has high stability in water and the amount of Si eluted in water is very small. In the crystalline silicate of the present invention, the amount of Si eluted into water is Si
It is usually 120 mg / g or less, preferably 90 mg / g or less, more preferably 60 mg / g or less in terms of O ₂ , and most of them are substantially insoluble in water. In the present invention, “substantially insoluble in water” means that 2 g of a sample is added to 100 g of ion-exchanged water and the amount of Si eluted when the mixture is stirred at 25 ° C. for 30 minutes is usually 120 m in terms of SiO _2.
Less than g / g.

The crystalline silicate in the present invention is widely used as a bleaching improver, and exhibits an excellent cation trapping ability for Ca, Mg and the like, an alkalinity adjusting ability and a buffering effect. In addition, when the crystalline silicate of the present invention is used as a bleaching-improving agent, it has excellent whiteness because it also has anti-redeposition ability and stabilizing ability of peroxide bleaching agent, which alkali metal silicates generally have. The texture and sewability can be imparted, and the drainage treatment is also good.

The amount of the bleaching improver of the present invention to be used is generally 0.1 to 20 g (solid content) / liter, preferably 0.5 to 10 g (solid content) / liter in the bleaching bath. Range is desirable.

The cellulosic fibers to which the bleaching improver of the present invention can be applied include, in addition to cellulosic natural fibers such as cotton and hemp, these cellulosic natural fibers and synthetic fibers such as nylon, polyester and acryl. It is also applicable to mixed fibers of the above, further, mixed fibers with semi-synthetic fibers such as acetate, mixed fibers with regenerated fibers such as rayon, cupra, etc. It may be in any form such as ribs, cheese, woven fabric, knitted fabric, non-woven fabric, and final fiber products such as clothing and bedding products.

As a bleaching method for bleaching a cellulosic fiber using the bleaching property improving agent of the present invention, a commonly used method can be applied. The pad-steam method, the pressure boiling method, about 60 ° C. A dipping method at a temperature of up to 100 ° C. or other methods can be applied. Further, the bleaching property improving agent of the present invention is applied not only to bleaching as described above, but also to bleaching performed simultaneously with other steps such as scouring / bleaching, desizing / scouring / bleaching. be able to.

By bleaching a cellulosic fiber in the presence of a bleaching improver of the present invention and an agent necessary for bleaching, such as hydrogen peroxide, even when water hardness is high,
Compared with the conventional bleaching method, the bleaching improver of the present invention has high cation exchange ability, alkali ability, pH buffering ability, stain redeposition preventing ability and bleaching agent stabilizing ability such as peroxide. Thus, excellent whiteness, texture and sewability can be imparted. Further, the bleaching property improving agent for cellulosic fibers of the present invention may be used in combination with an anionic, cationic, nonionic surface active agent or the like within a range in which the performance is not deteriorated. Surfactants that can be used in combination with the bleaching improver for the cellulosic fibers of the present invention include polyoxyethylene alkyl ethers, polyoxyethylene alkyl amines, polyoxyethylene alkyl ether sulfates, fatty acid ester sulfates, betaines. Examples thereof include amphoteric activators and the like.

[0021]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples. The measured values in the examples and comparative examples were measured by the following method. (1) Cation exchange capacity 0.1 g of a sample was precisely weighed and added to 100 ml of an aqueous calcium chloride solution (concentration: 500 ppm as CaCO ₃ ),
After stirring at 25 ° C. for 60 minutes, filtration was performed using a membrane filter having a pore size of 0.2 μm (manufactured by Advantech, nitrocellulose), and the amount of Ca contained in 10 ml of the filtrate was measured by EDTA titration. The calcium ion exchange capacity (cation exchange capacity) of the sample was determined from the value.

(2) Elution amount of Si 2 g of a sample was added to 100 g of ion-exchanged water, and the mixture was mixed at 25 ° C. for 3 hours.
Stir for 0 minutes. After that, centrifugation is performed, and the supernatant is filtered using a membrane filter having a pore size of 0.2 μm. The Si concentration in the filtrate was analyzed by plasma emission spectrometry (IC
P), and the elution amount of Si was calculated in terms of SiO ₂ .

(3) Alkali Ability 1 g of a sample was precisely weighed, suspended in 1000 ml of ion-exchanged water, and 10 ml of 0.25N hydrochloric acid was added dropwise with stirring, and the pH of the suspension was 9.0 to 12. Those having a pH of 0.0 were judged to have good alkalinity, and when the pH was less than 9.0, they were judged to have insufficient alkalinity.

Example 1 No. 2 sodium silicate (SiO ₂ / Na ₂ O = 2.5) 100
4.2 parts by weight of sodium hydroxide was added to parts by weight, and the mixture was stirred with a homomixer to dissolve the sodium hydroxide. To this, 10 parts by weight of finely ground anhydrous calcium carbonate was added and mixed using a homomixer. An appropriate amount of the mixture was placed in a nickel crucible, fired at 700 ° C. in the air for 1 hour, quenched, and the fired body obtained was pulverized to obtain a bleaching improver powder 1 of the present invention. The cation exchange capacity of this powder was as high as 251 CaCO ₃ mg / g, and the amount of eluted Si was 21.5 SiO ₂ mg / g, which was excellent in water resistance. In addition, powder X-ray (Cu
The Kα) diffraction pattern was a substance showing a main diffraction peak at d = 3.95 ± 0.1 A and showing a novel crystal structure different from that of the mixture before firing.

Examples 2 to 4 Bleachability improver powder of the present invention was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was changed by changing the amount of anhydrous calcium carbonate added. Body 2-4 were obtained. The cation exchange capacity and Si elution amount of the obtained powder were measured. The results are shown in Table 1. As with the bleaching improver powder 1, the cation exchange capacity and the water resistance are both excellent. It was The powder X-ray (CuKα) diffraction pattern of the obtained fired body was d = 4.17 to 2.05.
The substance had a main diffraction peak in A and was a substance having a novel crystal structure different from that of the mixture before firing.

Examples 5 and 6 The same procedure as in Example 1 was repeated except that anhydrous calcium carbonate and anhydrous magnesium carbonate were used in place of anhydrous calcium carbonate in Example 1 to obtain the compositions shown in Table 1. Bleachability improver powders 5 and 6 of the invention were obtained. The cation exchange capacity and Si elution amount of the obtained powder were measured, and the results are shown in Table 1. As with the bleaching improver powder 1, the cation exchange capacity and water resistance were both excellent. It was Further, the powder X-ray (C
The uKα) diffraction pattern showed a main diffraction peak at d = 4.17 to 2.05 A, and each was a substance having a novel crystal structure different from that of the mixture before firing.

Examples 7 and 8 In place of No. 2 sodium silicate in Example 1, silica stone powder and potassium hydroxide of 325 mesh pass or silica stone powder and sodium hydroxide, potassium hydroxide and anhydrous magnesium carbonate were used. Bleachability improver powders 7 and 8 of the present invention were obtained in the same manner as in Example 1 except that the composition shown in 1 was used. Cation exchange capacity and S of the obtained powder
The i elution amount was measured and the results are shown in Table 1. As with the bleaching improver powder 1, the cation exchange capacity and water resistance were both excellent. In addition, the powder X of the obtained fired body
Line (CuKα) diffraction pattern is d = 4.17-2.0
5A shows a main diffraction peak, and each substance has a novel crystal structure different from that of the mixture before firing.

Examples 9 and 10 500 g of 10 g of the anhydride obtained in Examples 3 and 8
Dispersed in ion-exchanged water for 1 hour and filtered through a 0.2 μm membrane filter to remove residue on the filter for 10 hours.
It was dried at 0 ° C. for 16 hours to obtain bleachability improving agent powders 9 and 10 of the present invention, which were hydrates of those obtained in Examples 3 and 8, respectively. The cation exchange capacity and Si elution amount of the obtained powder were measured. The results are shown in Table 1. As with the bleaching improver powder 1, the cation exchange capacity and the water resistance are both excellent. It was The powder X-ray (CuKα) diffraction pattern of the obtained fired product was d = 10.
It was a substance showing a main diffraction peak at 40 to 3.98 A and a novel crystal structure different from that of the mixture before firing.

[0029]

[Table 1]

Comparative Example 1 Sodium silicate 1.9 was added to 100 parts by weight of No. 2 sodium silicate.
Parts by weight were added, and sodium hydroxide was dissolved using a homomixer. Take an appropriate amount of this in a nickel crucible,
It was calcined in air at a temperature of 0 ° C. for 1 hour. After rapid cooling, pulverization was performed to obtain comparative powder 1. The cation exchange capacity of this powder was a low value of 142 CaCO ₃ mg / g. The amount of Si eluted was 3.8 SiO ₂ mg / g.

Comparative Example 2 To 100 parts by weight of sodium silicate No. 2 was added 28 parts by weight of sodium hydroxide, and the sodium hydroxide was dissolved using a homomixer. Take an appropriate amount of this in a crucible made of nickel, 700
It was calcined in air at a temperature of ° C for 1 hour. After rapid cooling, pulverization was performed to obtain comparative powder 2. The cation exchange capacity of this powder is 9
Low as 1CaCO ₃ mg / g, Si elution amount is 171S
The water resistance was inferior to iO ₂ mg / g.

Comparative Example 3 No. 2 sodium silicate was used as Comparative Powder 3. The cation exchange capacity of this powder was as low as 59 CaCO ₃ mg / g, and the whole amount was dissolved in water glass so that the water resistance was poor.

[0033]

[Table 2]

Example of Preparation of Bleachability Improver A bleaching solution prepared by using the bleachability improver for cellulosic fibers of the present invention is No. Nos. 1 to 10 and comparative bleaching solutions prepared using comparative powders were No. Table 3 shows an example of the composition of 11 to 14. The evaluation results of texture, whiteness and sewability are also shown in Table 3.
Shown in.

[0035]

[Table 3]

Test Example 1 (Bleaching Performance Test) A scoured knitted cotton knitted fabric was bleached using the bleaching property improving agent of the present invention, and its bleaching property was examined. <Bleaching conditions> Hardness of used water 20 ° DH Bath ratio 1 to 25 Temperature 80 ° C. Time 30 minutes Chemicals for bleaching See Table 3

<Evaluation> The texture of the treated cloth was judged by a sensory test method, and the results are shown in Table 3. The whiteness is SM color computer SM-3 manufactured by Suga Test Instruments Co., Ltd.
Colorimetry using a mold, Lab system of whiteness equation W = 100 - ^{[(100-L) 2 + a} 2 + b 2 ] ^1/2 (wherein, L; measured brightness, a, b; measured The whiteness (W) was obtained by the chromaticity index) and evaluated. For sewing, 4 pieces of cloth are piled up and needle # 11 is used with a lockstitch sewing machine.
It was evaluated by the number of ground yarn breakage points when 30 cm was sewn empty using S.

Test Example 2 (Wastewater Treatment Test) 1000 ml of the bleaching solution before use (an aqueous solution containing a bleaching improver and a bleaching agent at a predetermined concentration) used in Table 3 was further diluted 100 times with distilled water. The treatment liquid was treated by the coagulation precipitation method using ferric chloride. The results are also shown in Table 3. <Wastewater treatment method> Add HCl to the 100-fold diluted product,
After adjusting the pH to 5, ferric chloride was added, calcium hydroxide was added, and the pH was adjusted to 7 and then filtered, and the COD value of the obtained filtrate was measured.
pm) and evaluated.

As is clear from the evaluation results in Table 3, all of the bleaching solutions containing the bleaching property improving agent of the present invention were excellent in texture, whiteness, sewability and drainage. In contrast, hydrogen peroxide, caustic soda, and No. 2 sodium silicate only (No. 14) have a hard texture, whiteness,
The sewability is also inferior, and the one using ethylenediaminetetraacetic acid in combination (No. 13) does not significantly improve the bleaching property, which causes an increase in COD during wastewater treatment. Further, the comparative bleaching solutions (Nos. 11 and 12) also did not reach the level of the blending system of the present invention in terms of texture, whiteness and sewability.

[0040]

By using the bleaching property improving agent of the present invention, excellent bleaching performance, which was difficult with the conventional bleaching solution, can be obtained, and even when the hardness of water is high, compared with the conventional bleaching method. It is possible to provide excellent texture, whiteness, and sewability, and to promote the eutrophication of rivers and lakes, which has become a problem in recent years, and to be concerned about the adverse effects on the ecosystem. Reduce the use of, or allow not to use.

Claims (5)

[Claims] 1. The general formula of the anhydride is xM ₂ O.ySi.
O ₂ · zM ′ O (In the formula, M represents Na and / or K,
M ′ represents Ca and / or Mg, and y / x = 0.5 to
It is 4.0 and z / x = 0-1.0. ) A bleachability improving agent for a cellulosic fiber represented by the crystalline silicate represented by (4) and / or its hydrate. 2. The general formula of claim 1, wherein the crystalline silicate has y / x = 0.5 to 1.9 and z / x = 0.00.
5 to 1.0, K / Na in M ₂ O = 0.01 to 8.0,
The bleachability improver for cellulosic fibers according to claim 1, wherein Mg / Ca in M'O is represented by 0 to 10. 3. The crystalline silicate has a cation exchange capacity of 20.
The bleachability improving agent for cellulosic fibers according to claim 1 or 2, which has a CaCO ₃ mg / g of 0 to 600. 4. The amount of crystalline silicate eluted into water is Si.
The bleachability improving agent for cellulosic fibers according to claim 1, 2 or 3, which is 120 mg / g or less in terms of O ₂ . 5. The bleaching improving agent for cellulosic fibers according to claim 1, wherein the crystalline silicate has an alkaline ability that is a buffering action against an acid.