JPS616373A - Fiber sizing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sizing agent for warp yarns, and particularly to a fiber sizing agent that can be suitably used for spray set sizing.

Conventionally, sizing for warp threads has been done by dissolving sizing agents such as cornstarch, polyvinyl alcohol, polyacrylic acids, or oil emulsions in water and gelatinizing them.

A commonly used method is to soak the warp threads in this solution to impregnate it with the size agent solution, and then dehydrate and dry it. but.

This sizing method not only takes a considerable amount of time to dry, but also consumes a large amount of energy for drying, resulting in high costs.

It is extremely disadvantageous industrially.

In order to overcome the industrial disadvantages of such a warp sizing method, the present inventors have conducted extensive research on a convenient method of sizing, especially by spraying. It has been found that the warp yarns can be effectively spray sized using a certain sizing agent.

That is, 6 the present invention provides (1) a saponified product of a vinyl acetate polymer having a degree of polymerization of 100 to 1000, which has a degree of saponification of 40
~80 molti polyvinyl alcohol resin 10-30
Part by weight - (i) Mixing ratio of water and alcohol is 2:8 to 4
: Hydro-alcohol mixed solvent with a ratio of 6 to 90% to 7%
and (Ill) 0.1 to 0.5 parts by weight of a lubricant.

The sizing agent component used in the sizing agent of the present invention is about 10
It is a partially saponified polyvinyl alcohol resin derived from a vinyl acetate polymer having a degree of polymerization of 0 to 1000. In the present invention, the vinegar-based polymer includes a vinyl acetate homopolymer and a copolymer containing vinyl acetate as a main component and other monomers that can be copolymerized with the vinyl acetate homopolymer. Such copolymerizable monomers are particularly preferably monoethylenically unsaturated carboxylic acids, salts thereof, and amides thereof, although there are no particular restrictions, such as typical W1 monomers having a water-soluble group in one molecule. Such unsaturated carboxylic acids include - for example, acrylic acid,
Mention may be made of methacrylic acid, crotonic acid and itaconic acid. These salts are alkali metal salts and ammonium salts.

Practical amides include acrylamide and N-methylolacrylamide.

These comonomers may be used alone or in combination of 12 or more. The desirable upper limit of the ratio of introduction into the copolymer varies depending on the type of comonomer, but is generally VC 10 molar percentage or less.

The partially saponified polyvinyl alcohol resin used in the sizing agent of the present invention has a polymerization degree of 100 to 1 as described above.
It is prepared by saponifying 000 vinyl acetate polymer.

The degree of polymerization of the polymer is Zo.

If the I
If it exceeds 000, it becomes difficult to perform sizing by spraying, so it is not preferable.The desirable degree of polymerization is 200 to 5.
The range is 00. Further, the degree of saponification of the vinyl acetate polymer is selected from the range of 40 to 80 mol. If the degree of saponification is lower than 4QMo/I/Excellent, the thread will become sticky during sizing, and desizing will also become difficult, which is not preferable. If the diameter exceeds 8o-E, it is disadvantageous because it will not dissolve in the water-alcohol mixed solvent having a specific mixing range ratio for dissolving it. However, this degree of saponification.

Although there are some variations in vinyl acetate copolymers containing water-soluble comonomers as copolymerization components.

Even taking these into consideration, the preferred degree of saponification is 50 to 70 mol.

The solvent used in the sizing agent of the present invention preferably has a mixing ratio of water:hydratable alcohol in the range of 2:8 to 4:6, and particularly in spray sizing, it is preferable to dry quickly and effectively. It is imperative that this be done.

If the alcohol is more than this proportion - the partially saponified polyvinyl alcohol resin σ) is desirable as a sizing agent.
It is not preferable to use too much water because it is difficult to form cracks, and too much water interferes with drying. The alcohol used in the mixed solvent of the present invention is a lower alcohol that is mutually soluble in water, and examples thereof include methyl alcohol, ethyl alcohol, and isopropyl alcohol.

In the present invention, the partially saponified polyvinyl alcohol resin is dissolved in a water-alcohol mixed solvent, and the concentration and viscosity FC is suitable for spray sizing. #II is important. Although such a solution composition is not critical, solution proportions ranging from 10 to 30 parts by weight of resin to 90 to 70 parts by weight of mixed solvent are very commonly and practically advantageously employed.

Further, in the present invention, 0.1 to 0.5 parts of a lubricant is added to the above solution per 100 parts by weight. Such lubricants include, for example, polyether-modified silicone-polyethylene glycol and paraffin emulsions.

In the sizing agent of the present invention, a substance having good water-alcohol compatibility, such as polyether-modified silicone or highly polymerized polyethylene glycol, is preferably used as a lubricant. If the amount of lubricant used is less than 0.1 parts by weight, it is not preferable because it causes poor thread slippage and deteriorates the dividing property between the threads. Moreover, if it exceeds -0.5 part by weight, the conjugation force decreases, which is disadvantageous for knee contract. Preferably 0.
2 to 0.4 parts by weight are added.

Furthermore, the fiber sizing agent of the present invention may contain other additives commonly used in sizing agents, such as a fungicide and an antifoaming agent, if necessary.

The fiber sizing agent according to the present invention allows sizing with one spray method, and dries yarn easily.1) Especially!
P7! Since spray sizing can be performed at the time of weaving, the significantly improved sizing compared to conventional impregnating, dewatering and drying sizing is highly desirable to make the process industrially viable.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Polyvinyl acetate with a degree of polymerization of 350 was saponified.

15 parts by weight of partially saponified polyvinyl alcohol resin with a saponification degree of 65 mol was added and dissolved in 85 parts by weight of a mixed solvent of water:methyl alcohol with a weight ratio of 3 nia, and polyether-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a lubricant to this. -xp
-352) was added in an amount of 0.1 part by weight to prepare a sizing liquid. Pour this preparation into a hand-held sprayer and use 100% polypropylene and 20◆ fibers! ! ! When weaving was done by spraying it during weaving, we were able to weave extremely efficiently. In addition, when sizing polyester 100 mm at 75° using a single slasher system, the sizing speed was 60 mm/mm.
n 7! It became possible to increase the speed up to l' 120 Y/min, and the weaving was also good.

Examples 2 to 4 and Comparative Examples 1 to 4 In Example 1, different sizing agents were used.
The contents of each fiber sizing agent are shown in Table 1, and the results of experiments using them are summarized in Table 2.

In the specific example, since the experiment was carried out on polypropylene fibers, which are the most difficult to size, some unsatisfactory experimental results were observed even with the sizing agent of the present invention, but sufficiently satisfactory results were confirmed for other fibers. Also, it is difficult to stick to the fiber (it can be understood that it is desirable to introduce two selected comonomers for one fiber).

Claims (1)

[Scope of Claims] 1. (i) 10 to 30 parts by weight of a partially saponified polyvinyl alcohol resin having a saponification degree of 40 to 80 mol%, which is a saponified product of a vinyl acetate polymer having a degree of polymerization of 100 to 1000, ( ii) 90 to 70 parts by weight of a water-alcohol mixed solvent having a mixing ratio of water to alcohol in a weight range of 2:8 to 4:6; and (iii) 0.1 to 0.5 parts by weight of a lubricant. Fiber sizing agent.