JP2001172872A - Yarn sizing agent for prewet sizing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a yarn sizing agent capable of exhibiting sufficient weaving performances without destroying a sizing film by abrasion on a weaving machine, etc. SOLUTION: This yarn sizing agent for prewet sizing comprises (I) a polyvinyl alcohol and (II) a vinyl alcohol-based copolymer containing 2-19 mol% of a <=4C α-olefin unit in the molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber sizing agent having excellent weaving performance when weaving using various fibers. In particular, the present invention relates to an industrially useful fiber sizing agent which is suitable for a pre-wet sizing method which has been spotlighted in recent years and which can further exhibit the features obtained by the sizing method.

[0002]

2. Description of the Related Art As a sizing agent conventionally used for reinforcing a warp of a woven fabric, a polyvinyl alcohol polymer,
Starch, carboxymethylcellulose, water-soluble acrylic paste and the like are used. Of these, starch is a natural water-soluble polymer that has been used in warp sizing agents since the oldest, and because of its low price, it is still widely used, mainly in warp sizing agents for spun yarns. Since the size of the glue film was weak, it was necessary to increase the amount of glue adhered to the yarn with a high ratio of starch. In that respect, polyvinyl alcohol-based polymers are effective as a water-soluble glue for long-term storage without decay, and as a main component of glue instead of starch because the strength of the resulting film is very strong. became.

[0003]

The pre-wet sizing method, which has been receiving attention in recent years, is as follows.
This is a so-called two-stage gluing method in which the yarn is once passed through water just before gluing. The use of such a gluing method is characterized in that fluff is reduced, yarn strength is improved, and divide resistance during gluing is reduced as compared with a normal gluing method. In addition, since the wet core is present inside the yarn, the penetration of the sizing liquid into the yarn during sizing is suppressed, and the amount of sizing liquid absorbed is reduced and the amount of sizing is reduced. This is a revolutionary gluing method that can reduce the size. However, unlike the conventional sizing method, there is no function that the sizing agent penetrates into the yarn and adheres between the single fibers. When broken, the non-conjugating raw yarn may be exposed from the inside and the weaving property may be deteriorated on the contrary, and there is an industrial difficulty. The present invention has been made in view of the above circumstances to provide a fiber sizing agent which is most suitable for a pre-wet sizing method.

[0004]

The present inventors have conducted intensive studies to develop a fiber sizing agent for pre-wet sizing having the above-mentioned preferable properties, and as a result, surprisingly, (I) polyvinyl alcohol and ( II) It has been found that the problem of the present sizing method can be solved by using a fiber sizing agent composed of a vinyl alcohol-based copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms in the molecule. Thus, the present invention has been completed.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The (I) polyvinyl alcohol used for the fiber sizing agent suitable for prewet sizing of the present invention is a polymer of vinyl ester, and (II) α having 4 or less carbon atoms in the molecule.
-A vinyl alcohol-based copolymer containing 2 to 19 mol% of olefin units is composed of a vinyl ester and α having 4 or less carbon atoms.
-Obtained by saponifying a copolymer with an olefin. There are no particular restrictions on the method for producing (I) polyvinyl alcohol and (II) a vinyl alcohol-based copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms in the molecule. Polymerization by a known polymerization method such as solution, suspension or emulsification, or
It can be obtained by saponifying a polyvinyl ester (co) polymer obtained by copolymerizing the following α-olefin unit by a known method. The vinyl ester is not particularly limited, and examples thereof include vinyl formate, vinyl acetate, vinyl propionate, and vinyl pivalate, and vinyl acetate is often used.

The α-olefin unit having 4 or less carbon atoms used in the present invention is not particularly limited as long as it can be copolymerized with a vinyl ester, and examples thereof include ethylene, propylene, n-butene and isobutene. Ethylene is often used for convenience of industrial use. Carbon number 4
The content of the following α-olefin is essential to be 2 to 19 mol%, preferably 2.5 to 17 mol%, more preferably 3 to 15 mol%, and more preferably 3.5 to 13 mol%.
Molar% is particularly preferred. When the content of the α-olefin having 4 or less carbon atoms is less than 2 mol%, the effect of improving physical properties such as reduction of fluff, strong yarn strength and low divide resistance at the time of sizing is small, and exceeds 19 mol%. In such a case, the water solubility or water dispersibility is reduced, so that the desizing property of the woven fabric becomes poor, which is inappropriate. In addition, (I) of the present invention
I) The content of the α-olefin in the α-olefin-containing vinyl alcohol-based copolymer having 4 or less carbon atoms is determined based on the content of the α-olefin-containing vinyl ester-based copolymer which is a precursor of the vinyl alcohol-based copolymer. It was determined from proton NMR.

[0007] (I) Polyvinyl alcohol and (II) a vinyl alcohol copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms in the molecule used in the fiber sizing agent for prewet sizing of the present invention. The viscosity average degree of polymerization of PVA (hereinafter abbreviated as degree of polymerization) is preferably 1
00 to 4000, more preferably 200 to 300.
0, and more preferably 300 to 2500. If the degree of polymerization is less than 100, satisfactory weavability may not be obtained, probably because the strength of the sized yarn obtained is reduced. If the degree of polymerization exceeds 4,000, the viscosity of the aqueous solution at the time of sizing becomes high and the work becomes difficult. In some cases, its use deteriorates and its use is restricted.

The degree of polymerization (P) of PVA is determined according to JIS-K67.
26 is measured. That is, it is obtained by the following equation from the intrinsic viscosity [η] measured in water at 30 ° C. after re-saponifying and purifying PVA. P = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

(I) Polyvinyl alcohol and (II) a vinyl alcohol copolymer containing an α-olefin unit having 4 or less carbon atoms in the molecule in an amount of 2 to 19 mol% in the fiber sizing agent for prewet sizing of the present invention. The degree of saponification of the vinyl ester portion of is not particularly limited;
-100 mol%, more preferably 70-99.9 mol%. When the saponification degree is less than 60 mol%, the water solubility or water dispersibility tends to decrease, and the viscosity at the time of sizing may become unstable, or the desizing property of the woven fabric may be limited. .

The (I) polyvinyl alcohol used in the present invention and (II) the vinyl alcohol copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms in the molecule are water-soluble or water-dispersible. In view of the above, it can be further modified by a modified species other than those described above. Such a comonomer unit is not particularly limited as long as it can be copolymerized with a vinyl ester. For example, α-olefins having 5 or more carbon atoms, acrylic acid, methacrylic acid, fumaric acid, acrylonitrile, methacrylonitrile, acrylamide , Methacrylamide, trimethyl- (3-acrylamido-3-dimethylpropyl) -ammonium chloride, ethyl vinyl ether, butyl vinyl ether, N-vinylpyrrolidone, vinyl chloride, vinyl bromide,
Vinyl fluoride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, (anhydrous) itaconic acid, (anhydrous)
Examples include, but are not limited to, maleic acid, acrylamido-2-methylpropanesulfonic acid and its sodium salt, sodium vinylsulfonate, sodium allylsulfonate, and the like. When the comonomer is used, a preferred content of the monomer is 10 mol% or less, more preferably 7 mol% or less, and even more preferably 5 mol%.
It is as follows. Further, it is preferably at least 0.1 mol%, more preferably at least 0.2 mol%. When the content of the comonomer exceeds 10 mol%, the effect of the present invention may be inhibited, and the use thereof may be restricted.

There are no particular restrictions on the mixing ratio of (I) polyvinyl alcohol used in the present invention and (II) a vinyl alcohol-based copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms in the molecule. There is no choice between natural fibers, artificial fibers, synthetic fibers, filaments, spun yarns, blended yarns, and the like, depending on the count, etc. (I) polyvinyl alcohol and (II) The vinyl alcohol-based copolymer containing 2 to 19 mol% of α-olefin units having 4 or less carbon atoms is in a weight ratio.
(I) / (II) = range of 90/90 to 90/10, especially 20/80 to 70/30, further 25/75
The range from to 50/50 is preferred. Thus (I)
By blending with (II), the wear strength can be improved.

The fiber sizing agent for prewet sizing according to the present invention is a water-soluble polymer such as starch, a water-soluble cellulose compound, a water-soluble acryl sizing agent, or a smoothing agent such as wax or oil as long as the effect is not impaired. And other additives such as antifoaming agents, antistatic agents, preservatives, and fungicides. As the starches, raw starch or processed starch obtained by subjecting raw starch to gelatinization (gelatinization), oxidation, esterification, etherification, grafting, carboxymethylation and the like can be suitably used. As a raw material for these starches, those produced from natural grains such as corn, potato, wheat, tapioca, rice and the like can be used. Examples of the water-soluble cellulose compound include, but are not limited to, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, and the like. Similarly, the water-soluble acrylic paste, leveling agent, and other additives can be appropriately used without any particular limitation.

[0013]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified.

Example 1 By saponifying a vinyl acetate polymer by a conventional method, polyvinyl alcohol-1 (abbreviated as PVA-1) having a degree of polymerization of 1470 and a degree of saponification of 90 mol% was obtained. By saponifying a copolymer consisting of 5.0 mol% of ethylene units and 95.0 mol% of vinyl acetate units, a vinyl alcohol-based copolymer having a saponification degree of vinyl acetate units of 98.5 mol% and a polymerization degree of 1450 is obtained. Polymer-A (abbreviated as copolymer-A) was obtained. A size solution having the following formulation was prepared using PVA-1 and the copolymer-A, and the size was adjusted with a pre-wet type test sizer. A high wear strength of 612 times was obtained at 0.4%, and polyvinyl alcohol and carbon number 4 were obtained.
The effect of the present invention using a vinyl alcohol-based copolymer obtained by using ethylene as the following α-olefin is apparent. (1) Glue formulation PVA-1 32 parts Copolymer-A 60 parts Wax for fiber sizing agent (Wapset 600 manufactured by Takemoto Yushi Co., Ltd.) 8 parts (2) Gluing conditions Raw yarn: polyester / cotton blended yarn (( 1013C 45/1 manufactured by Kuraray Co., Ltd. Gluing machine: 20 test sizers Gluing device 1 box 1 sheet type However, a water tank for pre-wet is installed before the glue tank (Pre-wet tank squeezing pressure: 50 kg / cm) Pre-wet Vessel and size liquid temperature: 90 ° C Size roller squeezing roll air pressure: 2.0 kg / cm ² Yarn speed: 40 m / min Drying temperature: 110-120 ° C

Example 2 A test was conducted in the same manner as in Example 1 except that a paste solution having the following formulation was prepared using PVA-1, copolymer-A and raw corn starch. Wear strength 5 at .2%
A high wear strength of 55 times is obtained, and the present invention using the polyvinyl alcohol of the present invention and a vinyl alcohol-based copolymer obtained by using ethylene as an α-olefin having 4 or less carbon atoms is used when raw corn starch is blended. It is clear that also has an effect. (1) Glue formulation PVA-1 25 parts Copolymer-A 47 parts Raw corn starch 20 parts Fiber sizing wax 8 parts

Example 3 4.4 mol% of propylene units and 95.6 vinyl acetate units
By hydrolyzing the copolymer consisting of the polymer having a polymerization degree of 98.2 mol% and a polymerization degree of 13
A vinyl alcohol copolymer (abbreviated as copolymer-B) obtained by using propylene as the α-olefin having 4 or less carbon atoms and having a carbon number of 00 was obtained. Except for using PVA-1 and copolymer-B to prepare a size liquid having the following formulation, the same test as in Example 1 was carried out. High wear strength was obtained. From this, the effect of the present invention using a polyvinyl alcohol-based copolymer obtained by using propylene as the α-olefin having 4 or less carbon atoms with polyvinyl alcohol is apparent. (1) Glue formulation PVA-1 32 parts Copolymer-B 60 parts Fiber sizing wax 8 parts

Example 4 Saponification of a copolymer consisting of 7.0 mol% of propylene units, 1 mol% of sodium allyl sulfonate units and 92.0 mol% of vinyl acetate units gave a degree of saponification of vinyl acetate units. A vinyl alcohol-based copolymer (abbreviated as copolymer-C) having 98.1 mol% and a degree of polymerization of 1000 was obtained. Except for using PVA-1 and copolymer-C to prepare a size liquid having the following formulation, the same test as in Example 1 was carried out. High wear strength was obtained. From this, α- with less than 4 carbon atoms
It is clear that the olefin-containing vinyl alcohol copolymer is effective even if it contains sodium allyl sulfonate units. (1) Glue formulation PVA-1 32 parts Copolymer-C 60 parts Fiber sizing agent wax 8 parts

Comparative Example 1 The same test as in Example 1 was conducted except that only PVA-1 was used and no vinyl alcohol copolymer containing an α-olefin having 4 or less carbon atoms was used. Adhesion amount is 1
Although it was 0.5%, the wear strength was as low as 452 times. From this, the effect of the present invention using a polyvinyl alcohol copolymer containing polyvinyl alcohol and an α-olefin having 4 or less carbon atoms in the molecule is apparent. 1) Glue formulation PVA-1 92 parts Wax for fiber sizing agent 8 parts

Comparative Example 2 A similar test was conducted except that copolymer-B was used in place of PVA-1 of Comparative Example 1. The amount of gluing was 10.3%, but the abrasion strength was 540. And the wear strength was low. From this, the effect of the present invention using a polyvinyl alcohol copolymer containing polyvinyl alcohol and an α-olefin having 4 or less carbon atoms in the molecule is apparent. 1) Paste formulation 92 parts of copolymer-B 8 parts of wax for fiber paste

[0020]

The fiber sizing agent for pre-wet sizing of the present invention exhibits excellent binding force even when the sizing agent adheres only to the surface layer by the same sizing method. Thereby, sufficient weaving properties can be exhibited without breaking the glue film.

Claims (1)

[Claims] (1) Polyvinyl alcohol and (I)
I) An α-olefin unit having 4 or less carbon atoms in the molecule
A fiber sizing agent for prewet sizing comprising a vinyl alcohol-based copolymer containing 19 mol%.