JPH0680233B2 - Fiber sizing agent - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber which exhibits excellent performance regardless of the type of fiber such as filament yarn and spun yarn, and when using any of a normal loom and an air jet loom loom. The present invention relates to a sizing agent.

[0002]

2. Description of the Related Art As a sizing agent for fibers, conventionally, filament yarns have been made of acrylic, polyvinyl alcohol (hereinafter referred to as PV
A resin (abbreviated as A) or the like is used. In particular, in the use of warp sizing agents, it has been attempted to use PVA containing a sulfonic acid group for the purpose of improving the tying force for fibers and further improving the drop size. (Meth) allyl sulfonic acid (sodium)
And vinyl acetate are copolymerized, and the resulting copolymer is saponified.

[0003]

However, since the PVA modified with allyl sulfonic acids does not give a resin having a high degree of polymerization, the sizing agent for fibers is poor in strength and abrasion resistance of the sizing fiber. Thread breakage and fluffing are likely to occur, and their solution is needed.

[0004]

However, as a result of intensive studies by the present inventors in order to solve such problems, the inventors of the present invention found that the copolymer of N-sulfoalkyl (meth) acrylamide and vinyl acetate shown in Chemical formula 1 was used. Sulfonic acid group content obtained by saponification is 0.1 to 20 mol%, average saponification degree is 10 to 99.9.
In order to complete the present invention, it was found that when a composition of sulfonic acid group-containing modified PVA and starch having a viscosity of a 4% by weight aqueous solution of 20% by mol at 20 ° C. is used as a sizing agent for fibers, this purpose is met. I arrived.

[0005]

[Chemical 1] (R ₁ ; hydrogen or methyl group, R ₂ ; alkylene group, M; hydrogen or alkali metal)

The sulfonic acid-modified PVA of the present invention is characterized in that it has a high degree of polymerization.
Since it is A, it exhibits the excellent effects of the present invention. Hereinafter, the present invention will be described in detail.

The adhesive of the present invention is a modified PVA obtained by copolymerizing N-sulfoalkyl (meth) acrylamide and vinyl acetate and saponifying as described above. In N-sulfoalkyl (meth) acrylamide, the alkylene group (R ₂ ) may be linear or branched such as ethylene group, propylene group, butylene group, etc., but the stability of the copolymer during saponification is important. Therefore, those containing a branched alkylene group are preferable. Also, M is hydrogen or an alkali metal,
Since free sulfonic acid (M is hydrogen) may decompose vinyl acetate during copolymerization, alkali metals such as sodium and potassium are usually desirable. Among such acrylamides, N-sulfoisobutylene acrylamide sodium salt 2 is particularly preferably used in the present invention.

[0008]

[Chemical 2]

In producing the above-mentioned modified PVA, first, N-sulfoalkyl (meth) acrylamide and vinyl acetate are copolymerized in an alcohol solvent. In this case, modified P
The amount of alcohol used must be 50% or less based on the weight of vinyl acetate so that the viscosity of VA is 5 centipoise or more. The viscosity is measured with a 4 wt% aqueous solution at a temperature of 20 ° C. using a B-type rotational viscometer.

As the alcohol, lower alcohols such as methanol, ethanol and propanol are usually used. These alcohols may contain a small amount of water. There is no particular limitation on the charging method of the monomers during the polymerization, and any method such as batch charging, divided charging, continuous charging is adopted, but N-sulfoalkyl (meth)
From the viewpoint of the copolymerization ratio of acrylamide and vinyl acetate, it is advantageous to first dissolve vinyl acetate in an alcohol solvent and polymerize while adding the above (meth) acrylamide dropwise to the copolymer because it is easy to obtain a copolymer having a uniform composition. . As a catalyst for the copolymerization, known radical polymerization catalysts such as azobisisobutyronitrile, acetyl peroxide, benzoyl peroxide, lauroyl peroxide and the like are used. Polymerization temperature is usually 50
C. to boiling point is desirable.

In carrying out such polymerization, the above-mentioned 2
Other unsaturated monomers copolymerizable with the monomer other than the components, for example, styrene, alkyl vinyl ether, (meth) acrylamide, olefins such as ethylene, propylene, α-hexene, α-octene, and (meth) acryl. Unsaturated acids such as acids, crotonic acid, maleic acid (anhydrous), fumaric acid and itaconic acid, and their alkyl esters and alkali salts may be present in an amount of about 10 mol% or less. The copolymer thus polymerized is saponified according to a conventional method.

That is, upon saponification, the copolymer is dissolved in alcohol or hydroalcohol and saponified with acid or alkali. Examples of alcohol include methanol, ethanol, propanol and the like, and methanol is preferably used. The concentration of the copolymer in alcohol is usually selected from the range of 20 to 70% by weight. As the saponification catalyst, an alkali catalyst such as an alkali metal hydroxide or alcoholate such as potassium hydroxide, sodium hydroxide, sodium methylate, sodium ethylate or potassium methylate, or an acid catalyst such as sulfuric acid or hydrochloric acid is used. . The appropriate amount of such a catalyst is usually 0.1 to 5.0 mol% with respect to vinyl acetate. The temperature during the saponification reaction is not particularly limited, but is usually 10 to 50 ° C., preferably 20 to 50 ° C.
It is selected from the range of 40 ° C. The saponification reaction is conducted for 0.1 to 5 hours.

The modified PVA thus obtained has a sulfonic acid group content of 0.1 to 20 mol% and an average saponification degree of 10.
A highly polymerized sulfonic acid group-containing modified PVA having a viscosity of an aqueous solution of 99.9 mol% and 4% by weight at 20 ° C. is 5 centipoise or more, and particularly preferably 10 centipoise or more. If the sulfonic acid group content is less than 0.1 mol%, the sizing force for fibers as a sizing agent for fibers and the desizing property are insufficient,
If it exceeds 20 mol%, the modified PVA has a low degree of polymerization, and the desired sizing agent for fibers cannot be obtained. If the viscosity of the 4% by weight aqueous solution at 20 ° C. is less than 5 centipoise, the effect of the present invention cannot be obtained at all.

The starch in the present invention is not particularly limited, and raw starch, physically modified starch, enzyme-modified starch, chemically-degraded starch, and chemically-modified starch derivative can be arbitrarily used. The mixing ratio of the starch and the modified PVA is about 20:80 to 80:20 in weight ratio. The concentration of the sizing agent depends on the performance and workability of the sizing agent,
About 20% by weight is preferable. Conventionally known oils and fats, waxes and other oil agents, defoaming agents, penetrants and the like may be added to the liquid depending on the purpose.

[0015]

[Working] The sizing agent for fibers of the present invention is composed of sulfonic acid group-containing PVA having a high degree of polymerization and starch, and the strength and abrasion resistance of the sized yarn are remarkably improved as compared with the conventional sulfonic acid group-containing modified PVA. .

The present invention will be described in more detail below with reference to actual examples. The terms "part" and "%" are based on weight unless otherwise specified. Example 1 A polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer and a stirrer was charged with 834 parts of vinyl acetate and 158 parts of methanol, and the temperature was raised with stirring to raise the temperature at 60 ° C. to 0.30 of azobisisobutyronitrile. Polymerization was initiated by adding a solution prepared by dissolving 50 parts of methanol in 50 parts of methanol. From the start of polymerization,
N-sulfoisobutylene acrylamide sodium salt 4
Polymerization was continued while dropping 196 parts of a 23% methanol solution in which 6 parts were dissolved. After 5 hours, the polymerization was stopped when the polymerization rate reached 60%. The copolymer solution was purified by a conventional method to obtain an N-sulfoisobutylene acrylamide sodium salt / vinyl acetate copolymer.

A 30% methanol solution of the copolymer was prepared, and a saponification reaction was carried out by adding a methanol solution of 20 mmol of sodium hydroxide to vinyl acetate groups at 40 ° C. in a kneader. The produced modified PVA was separated by filtration, washed, and dried to obtain the desired product. The characteristic values of the obtained modified PVA were as follows.

Sulfonic acid group-containing modified PVA having a sulfonic acid group content of 3.0 mol% and an average saponification degree of 94.9 mol% 4% aqueous solution viscosity at 20 ° C .; 30.5 centipoise IR (cm ⁻¹ ) 1660 and 1540 (second amide group) 1040 and 630 (sulfonic acid group) NMR (δ ppm) 1.7-Assigned to CH _{3 From the} above, the amide bond is not cleaved by saponification of the copolymer, and Existence is confirmed.

Subsequently, a polyester / cotton = 65/35 mixed yarn and a # 45 single yarn were sized with the sulfonic acid group-containing modified PVA obtained above under the following conditions. Broad fiber production results were tested. (1) Paste prescription; (paste concentration 9%) N-sulfoisobutylene acrylic amide sodium modified PVA 70 parts Corn starch 30 parts Oil agent 4 parts

(2) Gelatinization conditions: 600 liters of water was poured into a 1600 liters cooker, 63 kg of modified PVA and 27 kg of corn starch were added with stirring, and then 1
Disperse at room temperature for 0 minutes. Then, the mixture is heated to a temperature of 95 ° C. or higher for about 30 minutes and gelatinized for about 50 minutes. Finally, 3.6 kg of the oil solution is dissolved and the volume is adjusted to 1000 liters with water. (3) Adhesion conditions; hot air and cylinder combined dry sizing machine, paste temperature: 90 ° C, speed: 5
0 yds / min, throttle pressure; own weight (100 kg) +1.5 kg / c
m ² , drying temperature: 90 to 100 ° C. (hot air), 10
It was glued at 0 to 120 ° C (cylinder). (4) Woven fabric conditions; TOYODA GL-8 cup change, 170 rpm, 69 to 72% RH, 15 to 20 ° C. The obtained results are summarized in Table 1.

Examples 2 to 5 Experiments were carried out in the same manner as in Example 1 except that the modified sulfonic acid group-containing PVA shown in Table 1 was used. The results are summarized in Table 1. Control Example An experiment was conducted in the same manner as in Example 1 using PVA modified with allyl sulfonic acid. The results are summarized in Table 1.

[0022]

[Table 1] (Note) For strength and elongation, sample length is 500m with autograph
Measured at m and pulling speed of 500 mm / min. Friction test is TM
The fluffy state of the glued yarn before and after the rubbing was observed by rubbing 500 times with a load of 400 g / 20 yarns using a type tie tester. Judged from 1st grade (good) to 7th grade (bad).

[0023]

[Effect] The sizing agent for fibers of the present invention is composed of a modified PVA having a high degree of polymerization and modified starch, and the strength and abrasion resistance of the sized yarn are significantly improved as compared with the conventional modified PVA containing a sulfonic acid group. Therefore, it is industrially advantageous.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location D06M 15/11 15/333 D06M 15/333

Claims (1)

[Claims] 1. A sulfonic acid group content obtained by saponifying a copolymer of N-sulfoalkyl (meth) acrylamide and vinyl acetate represented by Chemical formula 1, 0.1 to 20 mol%, and an average saponification degree of 10 A sizing agent for fibers composed of modified polyvinyl alcohol having sulfonic acid groups and a starch having a viscosity of 99.9 mol% and 4% by weight at 20 ° C. of 5 centipoise or more. (R ₁ ; hydrogen or methyl group, R ₂ ; alkylene group, M; hydrogen or alkali metal)