JP2670863B2 - Glue - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a low-temperature sizing agent for warp, particularly a compounding sizing agent capable of dramatically lowering sizing temperature and sizing temperature and dramatically improving weavability. And a method for low-temperature sizing of warps using the sizing agent.

[Conventional technology]

Conventionally, as a sizing agent for spun yarn such as natural fiber or synthetic fiber, a mixture of starch, polyvinyl alcohol (hereinafter abbreviated as PVA), an acrylic agent, an oil agent and the like has been used. The blending ratio of each of these components and the paste-making conditions are based on many years of experience of sizing companies.
In consideration of the gelatinization properties of the constituent starches and the permeation of the sizing agent into the warp yarns, the normal working temperature is 90 to 95 ° C and the sizing temperature is 85 to 95 ° C.

Recently, however, energy costs have increased due to high-temperature sizing and high-temperature sizing, problems in work safety due to high-temperature operation, turbulent flow of high-temperature sizing liquid causing uneven adhesion of the sizing agent on the yarn, and steam condensation. Various problems have been pointed out, such as water droplets causing unevenness in water content of the yarn. For this reason, a new warp sizing agent, including a review of sizing conditions,
In particular, there is a demand for a sizing agent that can form a paste at a relatively low temperature (50 to 70 ° C), has excellent compatibility with PVA, good viscosity stability, and good sizing and weaving properties. However, in order to meet these demands, sufficient results have not been obtained with pasted paste blending agents and commercially available blended pasting agents based on experience to date.

[Problems to be solved by the invention]

When preparing pastes that can be glued at a low temperature, have excellent compatibility with PVA, and have good viscosity stability, such as conventionally used corn starch, potato starch, wheat starch, tapioca starch, etc. Since raw starch has a high gelatinization start temperature, the low temperature (50 to 70 ° C.) targeted by the present invention
It is not possible to prepare a sizing paste that can be gelatinized, has low viscosity and viscosity stability, and is compatible with PVA.

On the other hand, of the modified starches, oxidized starch can lower the gelatinization temperature and lower the viscosity, but has poor compatibility with PVA and causes separation from PVA in the paste solution.
Not only does workability decrease, but a sufficient sizing effect cannot be obtained.

Positive starch, acetylated starch, or etherified starch such as hydroxyethyl starch or hydroxypropyl starch has a higher viscosity than the original starch, that is, unmodified starch during gelatinization, and has an unstable viscosity. The amount of permeation into water cannot be kept constant, and a sufficient sizing effect cannot be obtained.

As described above, starch can change the gelatinizing property by a chemical method, but no matter which method is adopted, there are advantages and disadvantages, and all of the above problems can be solved at once by one means. No way to get it yet.

[Means for solving the problem]

The present inventors have conducted various studies to solve these problems, and as a result, tapioca starch has a gelatinization temperature (temperature at which the maximum viscosity is reached) as compared with corn starch, potato starch, wheat starch, sago starch, etc. It has low viscosity and relatively low viscosity, so it has desirable properties as a sizing agent for sizing, but when used in combination with PVA, not only the viscosity increases but also it is unstable and the compatibility is poor, resulting in phase separation. Such as
It was found that it could not be used at all without being modified. Therefore, the present inventor pays attention to the above-mentioned desirable properties, and in order to make tapioca starch usable as a sizing agent for sizing, by modifying the starch by chemical treatment, it is possible to use it in combination with the PVA. I tried to solve the shortcomings of.

Table 1 shows the results of modifying tapioca starch by various chemical modification methods.

As is clear from this table, tapioca starch oxidizes to lower the gelatinization temperature and viscosity, but some of the starch is reduced in molecular weight, and the compatibility with PVA deteriorates, resulting in phase separation. Occurs. Also, acetylation lowers the gelatinization temperature, but the viscosity increases, the compatibility with PVA deteriorates, and phase separation occurs. Furthermore, the cationization lowers the gelatinization temperature, but the viscosity increases and the PVA
The compatibility with and deteriorates, resulting in phase separation.

Thus, a satisfactory modification result cannot be obtained by the chemical modification method using only the oxidation treatment or the acetylation treatment alone.

However, by applying a chemical treatment to the tapioca starch that uses both an oxidation reaction and an acetylation reaction, the gelatinization temperature is reduced to 70%.
The minimum viscosity is 40 to 260 BU (92.5 ° C) when the temperature is lowered to below ℃
As a result, they have found that the sizing temperature can be lowered and the weaving property can be drastically improved.

In the chemical conversion treatment of the present invention, the oxidation reaction can reduce the viscosity of tapioca starch without lowering its molecular weight and modify it to a viscosity suitable for sizing, and the acetylation reaction stabilizes the viscosity of the oxidized starch that has been oxidized. And PV
The compatibility with A can be improved.

The most important thing here is to significantly improve the compatibility of starch and PVA, which cannot be improved by individual chemical conversion methods such as oxidation and acetylation, due to the synergistic effect of the combined use of oxidation reaction and acetylation reaction. I have found that I can do it.

That is, the warp sizing agent of the present invention is constructed on the basis of these new findings, and the temperature is mainly 50 to 70 ° C., which is composed mainly of oxidized acetylated starch of tapioca and PVA having the gelatinizing properties as described above. It is a powder paste that can be used for paste sizing at low temperature.

In this case, when oxidized acetylated starch other than tapioca, such as oxidized acetylated corn starch, is used instead of oxidized acetylated tapioca starch, it is difficult to lower the gelatinization temperature, and the viscosity stability of the paste liquid is reduced. Since it is bad, the effect of the present invention cannot be obtained.

It is considered that this is due to the characteristic of tapioca starch that swelling property, solubility, and stability of paste solution are higher than those of other starches.

The oxidized acetylated tapioca starch used in the present invention is generally prepared by adjusting tapioca starch (40% slurry) to a temperature of 40 ° C. and a pH of 8 to 11 so that sodium hypochlorite is added to anhydrous starch 0.1 to 2.5. % (Available chlorine), and after an oxidation reaction for about 4 hours, the pH was lowered to 4 with hydrochloric acid to stop the reaction.
After adjusting the pH to 6.5 with caustic soda, washing and dehydrating, and preparing this dehydrated cake to make a 40% slurry, temperature 30 ℃,
Adjust the pH to 9, add vinyl acetate to 0.5 to 15% of anhydrous starch, and acetylate for about 1 hour, then add hydrochloric acid to adjust the pH.
It is produced by lowering the reaction to 6 to stop the reaction, repeating washing and dehydration several times, and drying.

PVA has a saponification degree of 80, which is commonly used for sizing pastes.
~ 90 mol% partially saponified, completely saponified with a saponification degree of 97 mol% or more, or a modified partially saponified product obtained by copolymerizing PVA with acrylic acid, etc.
A partially saponified product having a mol% and a degree of polymerization of 500 to 2000 is preferable from the viewpoints of solubility at low temperature, stability of viscosity, penetration and adhesion to warp and the like.

The mixing ratio of the oxidized acetylated starch and PVA is 20 to 5% of the starch.
It is appropriate to mix PVA in an amount of 80 to 50% with respect to 0%. If the content of oxidized acetylated starch is 50% or more, the abrasion resistance of the sizing yarn is inferior, which causes yarn breakage during weaving. When the PVA is 80% or more, the divide property in sizing is deteriorated, and the fluffing effect cannot be expected.

The low temperature sizing agent for warp of the present invention may contain an acrylic agent, an oil agent, an antistatic agent, etc., if necessary, in an amount of about 1 to 10% with respect to the mixture of starch and PVA, respectively. It can be the one normally used.

In the present invention, a sizing agent mainly composed of the above composition is used at a temperature of 40 to 70 ° C.
It is characterized by sizing and sizing at a low temperature.

〔Example〕

Next, one embodiment of the present invention will be described, but the present invention is not limited to this.

Example To a 40% slurry of tapioca starch adjusted to a temperature of 40 ° C. and pH 9, sodium hypochlorite was added in an amount of 1% of anhydrous starch (effective chlorine), and the oxidation reaction was continued at the same temperature for 4 hours. After completion of the reaction, the reaction was stopped by lowering to pH 4 with hydrochloric acid, adjusted to pH 6.5 with caustic soda, washed and dehydrated. This dehydrated cake was made into a 40% slurry, and 1.5% of vinyl acetate was added to anhydrous starch at a temperature of 30 ° C. and a pH of 9, followed by acetylation reaction for 1 hour, and then the reaction was stopped by lowering the pH to 6 with hydrochloric acid.
After that, washing and dehydration are repeated several times, followed by drying with a flash dryer to obtain an oxidized acetylated starch showing a property of a 6% amylograph having a maximum viscosity temperature (gelatinization temperature) of 68 ° C and a minimum viscosity of 100BU (92.5 ° C). Obtained. 30 parts of this oxidized acetylated tapioca starch, 50 parts of PVA (PVA 217 made by Clera),
An oil agent (Maconol 222 manufactured by Matsumoto Yushi Co., Ltd.) and 10 parts of a polyacrylic ester resin (Marposol T30 manufactured by Matsumoto Yushi Co., Ltd.) were mixed to prepare a low temperature sizing agent for warp yarns of the present invention. This sizing agent is made into a 12% aqueous solution at 70 ° C for 1 hour for gelatinization and dissolution (paste making).
Then, the stability and viscosity of this solution were measured. Moreover, it was placed in a tall beaker and the state of the paste solution was observed. On the other hand, as a comparative example, except that unmodified tapioca starch, oxidized tapioca starch (TAPCO-H manufactured by TDC of Thailand, TAPCO-H) and acetylated tapioca starch (Faradim-T manufactured by Matsutani Chemical Co., Ltd.) were used in the starch part The same formulation was used and the same test was conducted.

 Table 2 shows the results.

From the above results, it can be seen that the paste solution of the present invention has stable viscosity and good compatibility.

Test Example 1 Using the low temperature sizing agent for warp of the present invention prepared in Example, a slasher sizing machine was used to blend polyester / cotton.
After sizing the 45S warp, the physical property test and the weaving test of the sizing thread were performed.

As a comparative example, the same test as in Test Example 1 was conducted using a sizing agent prepared in the same manner as in Example except that tapioca starch was blended in the starch part.

 The results of these measurements are shown in Table 3.

From the above results, the sizing agent of the present invention, compared to the sizing agent of the comparative example,
It can be seen that the physical properties of the sizing yarn and the weaving performance are improved.
Further, the oxidative dissolution (paste-making) temperature of the sizing agent of the present invention is 70 ° C, and the sizing temperature is 70 ° C, which is lower than that of the comparative example.
Sizing is possible, which is advantageous in terms of workability and thermal economy.

Test Example 2 The physical property test and the weaving test of the sized yarn were performed in the same manner as in Test Example 1 except that cotton 40S was used as the warp. The comparative example was also performed in the same manner. Table 4 shows the results.

From the above results, the sizing agent of the present invention is compared with that of the comparative example,
It can be seen that the physical properties of the sizing yarn and the weaving test were all improved.

The measurement test methods and evaluation methods in Tables 3 and 4 are as follows.

(1) Conjugation force JIS-L-1095 Friction strength B method (initial load 300g, up to 3000 times) n = 3. [The larger the value, the better.] (2) Fuzz index JIS-L-1095 Fuzz B method F-INDEX TESTER n = 2
0. [The smaller the value, the better.] (3) Tensile strength and elongation JIS-L-1095 Instron type tensile tester n = 30.
[The larger the value, the better.] (4) Adhesion rate JIS-L-1095 Glue A method, C method, n = 2.

(5) Weaving ability 80 warp yarns / in × with Suyama type small loom (rotation speed 180 rpm)
Weaving was performed with a weft of 64 yarns / in and a fabric width of 33 cm.

〔The invention's effect〕

According to the present invention, low-temperature sizing (40 to 70 ° C) and low-temperature sizing (40 to 70 ° C) are possible, so that water drops and glue lees are reduced, and abrupt temperature change of the yarn is reduced. Not only can the sizing property and weaving property be improved, but the workability and safety of the working environment can be improved, and energy saving can be achieved.

Claims (4)

(57) [Claims] 1. A 6% amylograph, the temperature at which the maximum viscosity is reached (gelatinization temperature) is 50 to 70 ° C, and the minimum viscosity is 40 to 260 BU (92.5 ° C).
A low-temperature sizing agent for warps, which is mainly composed of a mixture of acetylated tapioca starch having the above properties and polyvinyl alcohol. 2. Polyvinyl alcohol has a saponification degree of 80 to 90.
The low-temperature sizing agent for warp according to claim 1, wherein the low-temperature sizing agent is a partially saponified product having a molar percentage of 500 to 2,000. 3. A 6% amylograph, the temperature at which the maximum viscosity is reached (gelatinization temperature) is 50 to 70 ° C, and the minimum viscosity is 40 to 260 BU (92.5 ° C).
A paste mainly composed of a mixture of oxidized acetylated tapioca starch and polyvinyl alcohol having the properties of
A low-temperature sizing method for warps, which comprises sizing at ~ 70 ° C and sizing. 4. The saponification degree of polyvinyl alcohol is 80 to 90.
The low-temperature sizing agent for warp according to claim 3, which is a partially saponified product having a mole percentage of 500 to 2,000 in terms of polymerization degree.