JPH07109678A - Production of sizing agent for water jet loom and sizing agent composition - Google Patents

Abstract

PURPOSE:To obtain a sizing agent for WJL having high cohesive force and low in viscosity and water-absorption by the soap-free emulsion polymerization of a monomer mixture composed of a polymerizable unsaturated acid and a specific ester. CONSTITUTION:This sizing agent composition for WJL having excellent water resistance can be produced by polymerizing a monomer mixture composed of 8-30wt.% of a polymerizable unsaturated acid [e.g. (meth)acrylic acid, itaconic acid or maleic acid], 30-70wt.% of a (meth)acrylic acid 1-3C alcohol ester and 20-60wt.% of a (meth)acrylic acid 4-22C alcohol ester in an aqueous solution in the presence of a water-soluble polymerization initiator and a chain transfer agent using a soap-free emulsion polymerization method, neutralizing the obtained aqueous dispersion with an alkaline agent and mixing the resultant neutral aqueous dispersion with a wax emulsion. The solid content of the neutral aqueous dispersion in the mixture is >=30% of the total solid content. The sizing agent can effectively prevent the breakage of warp in a high-speed weaving process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing a sizing agent for warp yarns suitable for water jet loom and a novel sizing agent composition. More specifically, the present invention has sufficient water resistance in a water jet room where a weft thread is inserted into the shed by the injection force of high-pressure water, the binding force of the fiber bundle as a sizing agent is sufficiently strong, and the viscosity is high. The present invention relates to a sizing agent manufacturing method and a sizing agent composition which are low and easy to handle during a weaving process.

[0002]

2. Description of the Related Art Conventionally, in the work of a textile factory,
Most of the preparation work in the fiber-making process is the warp yarn sizing work, and the quality of the warp yarn has a great influence on the efficiency of the loom and the quality of the product. If the sizing operation is unsuccessful, warp yarn breakage in the loom will increase, resulting in a decrease in efficiency and quality, and sometimes weaving will become impossible, and the warp yarn raw material will be wasted, and there is a risk of serious damage. PVA sizing agents are now widely used in place of starch, which has been used as a sizing agent for synthetic fibers since ancient times. However, PVA has insufficient adhesiveness to polyester and nylon filaments, and there is a dislike for the sizing thread to be too hard. Recently, therefore, acrylic sizing agents have been used for these synthetic fibers. . In recent years, jet looms have become widespread in order to improve the efficiency of the weaving process, and in Japan, water jet looms have become the mainstream. In the weaving process by this water jet loom method, the warp yarns are not only rubbed with the reeds and healds and with the adjacent yarns due to the shedding motion, but also the shedding motion of the yarns and the pulling and bending by the running. It receives a great deal of combined stress. In order to prevent the occurrence of yarn breakage and fuzzing due to such stress, it is necessary to use a warp yarn sizing agent that is particularly suitable for this water jet loom device.
In recent years, the weaving speed has been increased due to the rationalization of the fiber-making process, and the stress applied to the warp threads has been increased accordingly. Therefore, it is desired to develop a sizing agent having better weaving property and good conjugation property. In the water jet loom weaving process,
In order to run and weave the weft yarn with the flight force of high-pressure water, first, the warp yarn sizing agent is required to have water resistance. The woven fabric is then subjected to dyeing and finishing, but before that, the sizing agent and the oil agent must be removed in the scouring step. The processing time is also shortened due to the rationalization of the process, and therefore, the ability to remove the sizing agent in a short time is required. As a sizing agent for water jet rooms, a (meth) acrylic acid ester-ammonium (meth) acrylate copolymer is generally often used. This acrylic sizing agent is produced by solution polymerization as described in JP-B-40-19720, JP-B-45-28035, JP-B-61-25831, JP-B-61-46587 and the like. However, solution polymerization has a safety problem because the polymerization is carried out in a water-soluble flammable solvent such as a lower alcohol. Further, in solution polymerization, a step of replacing the alcohol solvent with an aqueous medium is necessary,
There is a drawback in that process costs such as solvent loss and solvent recovery cost increase excessively. If emulsion polymerization is used instead of solution polymerization, it is considered that there is an advantage that it is economical without the above-mentioned drawbacks due to the solvent, but this has the following drawbacks, so that water jet of polyester or nylon filament is used. It is not practical as a room paste. That is, since an emulsifier is used, the water resistance becomes poor and it cannot be put to practical use. Further, in order to give the fiber a practically sufficient conjugation force, if the polymerization degree is increased to the molecular weight required for the sizing agent polymer, the viscosity of the liquid becomes higher in the case of emulsion polymerization when compared with the same molecular weight. I will end up. When the viscosity of the sizing agent is high, the penetration of the sizing agent into the inside of the yarn is deteriorated, which causes a decrease in tying force and deterioration of weaving property due to falling glue.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing an acrylic sizing agent having good water resistance by emulsion polymerization as a sizing agent for water jet loom, and an acrylic sizing agent having good water resistance by the emulsion polymerization method. It is intended to provide a composition.

[0004]

Means for Solving the Problems The inventors of the present invention have made earnest studies on an acrylic sizing agent which has a low viscosity of the sizing agent by emulsion polymerization as a sizing agent for water jet loom and has good water resistance. Ability to achieve the desired performance unexpectedly by performing soap-free emulsion polymerization (emulsion polymerization without emulsifier) without using surfactant such as emulsifier or protective colloid agent in emulsion polymerization of copolymerization monomer The present invention has been completed, and the present invention has been completed based on this finding. That is, in the present invention, (1) the polymerizable unsaturated acid is 8 to 30% by weight, (2) the ester of an alcohol having 1 to 3 carbon atoms of (meth) acrylic acid is 30 to 70% by weight, and (3) ( A monomer mixture composed of 20 to 60% by weight of an ester of an alcohol having 4 to 22 carbon atoms of (meth) acrylic acid is polymerized by soap-free emulsion polymerization in a water system using a water-soluble polymerization initiator and a chain transfer agent. A method for producing a sizing agent comprising a neutralized aqueous dispersion obtained by neutralizing an aqueous dispersion with an alkaline agent, and (1) using a polymerizable unsaturated acid
To 30% by weight, (2) the carbon number of (meth) acrylic acid is 1 to
30 to 70% by weight of ester of alcohol of 3, (3)
Polymerization of a monomer mixture comprising 20 to 60% by weight of an ester of (meth) acrylic acid having 4 to 22 carbon atoms by a water-based soap-free emulsion polymerization using a water-soluble polymerization initiator and a chain transfer agent. Then, 10 to 30 parts by weight of the wax emulsion is mixed with 100 parts by weight of the neutralized aqueous dispersion obtained by neutralizing the aqueous dispersion with an alkaline agent to prepare a neutralized aqueous dispersion in the mixture. It is intended to provide a sizing agent composition having a content of 20% by weight or more of the total solid content as a solid content.

As the polymerizable unsaturated acid (1) used in the present invention, any monomer having a polymerizable unsaturated bond and a carboxylic acid group can be used without particular limitation. For example, acrylic acid and methacrylic acid. , Itaconic acid, maleic acid, crotonic acid and the like. The ratio of the polymerizable unsaturated acid in the copolymerization monomer mixture used in the present invention is 8 to 30% by weight.
If the monomer ratio is less than 8% by weight, the de-viscosity in the post-processing after weaving is insufficient, and if it exceeds 30% by weight, the glue film becomes hard and the elongation becomes small, and the elongation of the synthetic fiber becomes small. It is not preferable because it is unable to follow and the tying power is reduced and the falling glue becomes bad. Further, in the case of a water jet loom which requires water resistance, the water resistance is lowered, which is not preferable. As the monomer component of the copolymer used in the present invention, 30 to 70% by weight of (meth) acrylic acid ester of alcohol having 1 to 3 carbon atoms and 20 to 60 (meth) acrylic acid ester of alcohol having 4 to 22 carbon atoms are used. It is characterized in that it is used in a weight percentage. Examples of the ester of (meth) acrylic acid having 1 to 3 carbon atoms used in the present invention include methyl acrylate, ethyl acrylate, isopropyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate and the like. . 1-3 carbons
If the content of the (meth) acrylic acid ester of alcohol is less than 30% by weight, the paste film becomes too soft and the conjugation property and abrasion resistance decrease, and if it exceeds 70% by weight, the paste film becomes too hard and the yarn It is not preferable in that the conjugation property is deteriorated because it cannot follow the elongation of the.

Examples of the alcohol ester of (meth) acrylic acid having 4 to 22 carbon atoms used in the present invention include n-butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate and acrylic acid. n-octyl, lauryl acrylate, tridecyl acrylate, cetyl acrylate, stearyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, tridecyl methacrylate, cetyl methacrylate, methacrylic acid Stearyl and the like can be mentioned. If the amount of the (meth) acrylic acid ester of an alcohol having 4 to 22 carbon atoms is less than 20% by weight, the sizing becomes too hard to follow the elongation of the yarn, resulting in a decrease in conjugation.
When the content is more than 10% by weight, the adhesive film becomes too soft, which is unfavorable in that the conjugation property and the abrasion resistance are deteriorated. Further, as the copolymer component of the present invention, in addition to the monomers listed here, vinyl acetate, vinyl monomers such as vinyl chloride, acrylonitrile, acrylamide, monomers such as styrene within a range that does not impair the effects of the present invention as desired. It can be added. The polymerization method of the aqueous dispersion of the present invention is characterized by performing soap-free emulsion polymerization. This is, when conducting the polymerization in an aqueous system, without using a surfactant, an emulsifier such as a water-soluble polymer or a protective colloid, and using only a monomer mixture of a water-soluble polymerization initiator and a copolymerization component,
The mixture is vigorously stirred to disperse the monomer liquid, and the polymerization is performed up to a polymerization rate of 95% or more, preferably about 100%. The inventors of the present invention add a chain transfer agent to the monomer mixture shown in the claims of the present invention, carry out soap-free polymerization using a polymerization initiator, and neutralize with an alkali agent to achieve the purpose. However, it was discovered that the viscosity of the sizing agent at the same molecular weight is significantly lower than that of the sizing agents obtained by emulsion polymerization and solution polymerization using conventional emulsifiers and protective colloids. Therefore, it becomes possible to select polymerization conditions that further increase the molecular weight compared to conventional polymerization methods, and as a result, the conjugation force and abrasion resistance when used as a sizing agent can be significantly increased without increasing the viscosity of the sizing agent. It has become possible to improve.

Further, the emulsifier and protective colloid agent used for the polymerization, which is a big drawback of the conventional emulsion polymerization method, remain in the copolymer as they are, and therefore the water resistance is not lowered, and the water resistance of the sizing agent is drastically reduced. We were able to improve it. Further, as a characteristic of the sizing agent of the present invention, most particles of the obtained aqueous dispersion before neutralization, that is, 95
It is desirable that the weight percent or more has a particle size in the range of 0.2 to 2.0 μm micron. Particle size is 0.2
If the number of particles of less than μm is large, the viscosity of the sizing agent is high, which is not preferable, and if the number of particles of more than 2.0 μm is large, the film forming property is deteriorated, and the cohesive force is lowered, and the drop glue is apt to occur. Further, as a characteristic of the sizing agent of the present invention, the weight average molecular weight of the copolymer used is 80,000 to
400,000, preferably 100,000 to 300,
It is desirable to have 000. If the weight average molecular weight of the copolymer is less than 80,000, the binding force and abrasion resistance in high-speed weaving, which is the object of the present invention, tends to deteriorate, and if the weight average molecular weight exceeds 400,000, the sizing agent Viscosity increases and de-sizing property also decreases. In the soap-free emulsion polymerization in the present invention, those used in general emulsion polymerization such as ammonium persulfate and potassium persulfate as the polymerization initiator, and thioglycolic acid esters and alkyl mercaptans as the chain transfer agent are used. .
The polymerization temperature is 50 to 95 ° C., preferably 60 to 95 ° C.
80 ° C. is preferred. As the alkaline agent used for neutralization, ammonia water, lower alkylamines, morpholine and the like can be preferably used. Further, a volatile water-soluble solvent, for example, alcohols such as methanol, ethanol, propanol and isopropanol, and cellosolves such as methyl cellosolve can be appropriately added in order to reduce the viscosity of the sizing agent and impart permeability.

The sizing agent composition of the present invention is obtained by mixing a wax emulsion with a sizing agent comprising the neutralized aqueous dispersion produced by the production method of the present invention. Examples of the wax emulsion used in the paste composition of the present invention include:
Polyhydric alcohol fatty acid ester, paraffin wax,
Oxidized wax, oxidized polyethylene, carnauba wax,
An aqueous emulsion obtained by emulsifying waxes such as montan wax, candelilla wax, white wax and beeswax alone or a mixture thereof with a nonionic surfactant or anionic surfactant is used. The wax emulsion has a solid content of 30% by weight or more, preferably 4% by weight, based on the solid content of the neutralized aqueous dispersion.
It is blended so as to be 0% by weight or more. If too much wax is added, the conjugation property will decrease. The sizing agent obtained by the method of the present invention has improved water resistance, which has been a drawback of conventional emulsion polymerization, and can increase the molecular weight. It is possible to reduce the plasticization of the polymer, and the particle size of the aqueous dispersion can be reduced to 0.
By setting the particle size to 2 to 2.0 μm, it was possible to obtain a high molecular weight while keeping the viscosity low, so that it became possible to manufacture a sizing agent with good tying force and abrasion resistance suitable for a high-speed weaving process.

[0009]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 7 Chain transfer to predetermined amounts shown in Table 1 of methacrylic acid, acrylic acid, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, octyl methacrylate. Octyl thioglycolate as an agent was added in a predetermined amount shown in Table 1, and mixed by stirring to obtain a copolymerized monomer / chain transfer agent mixture. A 500 ml four-necked flask equipped with a thermometer, a stirrer, a condenser, and a N ₂ gas inlet was charged with 280 ion-exchanged water.
The mixture was charged in ml and heated to 75 ° C. while blowing N ₂ gas. Next, while stirring, 5% of the monomer / chain transfer agent mixture was added dropwise, an aqueous solution of ammonium persulfate / sodium bisulfite was added, and polymerization was carried out at 75 ° C. for 20 minutes, and then the remaining monomer / chain transfer agent mixture was added. Was added dropwise at 75 ° C. over 1 hour. Next, while continuing stirring, the temperature is 1 at 75 ° C.
After reaction for a time to complete the polymerization and cooling to a temperature of 65 ° C., 100 g of 5% aqueous ammonia is gradually added to neutralize
After cooling to room temperature, a neutralized aqueous dispersion was obtained. The neutralized aqueous dispersion thus synthesized was mixed with NK wax HW-9 (manufactured by Nichika Kagaku Co., wax emulsion obtained by emulsifying a high melting point wax with an emulsifier) at a solid content weight ratio of 80/20,
An emulsion composition having an aqueous dispersion in solid content of 80% by weight of solid content was prepared. The total solid content in the obtained emulsion composition containing no emulsifier was 22% by weight.

[0010]

[Table 1]

Comparative Examples 1 to 3 Monomer / chain transfer agent mixtures were prepared in the same manner as in Examples according to the formulations shown in Table 1. With this mixture,
Using the same device as in the example, 280 ml of ion-exchanged water and emulsifier TRAFFIX N-300 (Nippon Yushi) 1.0
An aqueous dispersion was prepared in the same manner as in Example except that g was charged. After neutralizing this in the same manner as in the example, NK wax HW-9 was further mixed in the same manner as in the example to prepare a paste using an emulsifier. The performances of the prepared sizing agents of Examples and Comparative Examples were evaluated by the following test methods, and the results are shown in Table 1. Particle size The particle size was measured with a laser diffraction particle size distribution analyzer SALD-1100 manufactured by Shimadzu Corporation using the aqueous dispersion before neutralization. The average particle size indicates the particle size at the 50% point of the integrated distribution curve. Sizing agent viscosity Using a neutralizing aqueous dispersion and using a BL type rotational viscometer (manufactured by Tokyo Keiki) at 30 revolutions of rotor No. 2, 20
It was measured at ° C. Molecular weight of sizing agent The neutralized aqueous dispersion prepared is dried at 100 ° C on a petri dish to form a film. This is dissolved in tetrahydrofuran as a solvent to obtain a 1% by weight solution. Using this solution, the average molecular weight was measured with a Tosoh GPC device HCL-8020. The tests (1) and (2) were measured using the aqueous dispersion alone before mixing the wax emulsion, while the tests (1) and (2) were performed on the sizing agent mixed with the wax emulsion. Water absorption rate A film with a thickness of 0.3 mm is used at 20 ° C and 60% RH for 4 days.
It was conditioned for 8 hours, immersed in warm water at 30 ° C. for 15 minutes, and determined from the weight change before and after immersion.

[0012]

[Equation 1]

Desizing Property A few drops of a sizing agent having a solid content adjusted to 10% are dropped on a polyester cloth, allowed to stand at room temperature for 1 day, heat-treated at 170 ° C. for 1 minute, and then scoured under the following conditions: Desizing property was judged by the following color reaction. For refining, use a refining agent of the following formulation with a bath ratio of 1:
Refining treatment was performed at 30 at 90 ° C. for 30 seconds. Scouring agent formulation Sanmor BL-600 1g / 1 Flake NaOH 1g / 1 Neocrystal 110 0.5g / 1 Coloration is 0.2g / with cationic dye Maxilon Blue 5G
1 was immersed in a bath ratio of 1:50 at a temperature of 50 ° C. for 5 minutes, and the test was performed according to the following criteria. [Judgment Criteria] ○: No coloration △: Slightly blue ×: Blue Adjustment of sample for performance evaluation method of sizing yarn The sizing agent was adjusted to 10% solid content, and polyester filament 50 denier 36 filament yarn (abbreviated as 50-36) ) Was pasted with a sizing machine so that the amount of glue applied would be 6 to 7%. Tying force (a) A TM type thread-metal friction tester was used to perform friction 1000 times while applying a load of 500 g and 19 threads, and the state of yarn cracking and fuzzing was visually observed according to the following criteria. [Judgment criteria] ○: Thread crack, no fluff ○ △: Some fluff △: Thread crack, some fluff ×: Thread crack, fluff (b) Thread-thread friction tie tester, load 1g / 1 denier The number of breaks of the yarn was obtained by rubbing at a crossing angle of 60 ° and a twist of 360 °. The evaluation results of the above-mentioned test are shown in Table 1. In the case of the examples according to the present invention, when compared with the same average molecular weight, the viscosity is orders of magnitude lower than that when the emulsifier is used. It is also clear that in the case of the examples according to the invention, the water absorption is lower than in the case of using the emulsifier and the tie force is clearly superior both in the case of thread-metal and in the case of thread-thread.

Example 8 A practical comparative test of sizing agent performance by a weavability test using the copolymer emulsions of Example 2 and Comparative Example 1 as a sizing agent was conducted on an industrial-scale high-speed loom. Copolymer resin emulsions were prepared in a pilot plant according to the polymerization formulations described in Example 2 and Comparative Example 1, and a wax emulsion (NK wax HW-9 manufactured by Nichika Kagaku Co., Ltd.) was added to the acrylic copolymer resin component: Formulated so that the wax solid content = 80: 20, and the concentration of this mixed solid content is 12%.
A sizing agent composition was prepared so that Using this sizing agent composition, polyester filament 50-24 yarns were sized using a beam-to-beam sizing machine. This yarn is looms 900 by using Nissan Water Jet Loom High Speed Loom LW-54
The following weaving test was performed on polyester taffeta as the woven fabric type at r.p.m. Weaving conditions Warp yarn 50-24 Weaving density Warp 77 yarns / inch Weft yarn 75-36 Horizontal 103 yarns / inch Number of warp yarns 5320 In the practical test of weaving under the same conditions, warp yarn breakage was observed in Comparative Example 2 8 was generated with the sizing agent of No. 2, whereas it was 0 with the sizing agent of Example 2.

[0015]

EFFECTS OF THE INVENTION According to the present invention, a sizing agent having no emulsifier, which has improved water resistance, high conjugation force, low viscosity, and low water absorption, can be produced safely and at low cost. In this case, the warp yarn breakage preventive property in the high-speed fiber manufacturing process is dramatically improved.

Claims (6)

[Claims] (1) 8 to 30% by weight of a polymerizable unsaturated acid,
(2) 30 to 70% by weight of an ester of (meth) acrylic acid having 1 to 3 carbon atoms, and 20 to 30% of (3) ester of (meth) acrylic acid having 4 to 22 carbon atoms.
A monomer mixture consisting of 60% by weight is polymerized by soap-free emulsion polymerization in a water system using a water-soluble polymerization initiator and a chain transfer agent to obtain an aqueous dispersion, which is then neutralized with an alkaline agent. A method for producing a paste comprising the obtained neutralized aqueous dispersion. (1) 8 to 30% by weight of a polymerizable unsaturated acid,
(2) 30 to 70% by weight of an ester of (meth) acrylic acid having 1 to 3 carbon atoms, and 20 to 30% of (3) ester of (meth) acrylic acid having 4 to 22 carbon atoms.
A monomer mixture consisting of 60% by weight is polymerized by soap-free emulsion polymerization in a water system using a water-soluble polymerization initiator and a chain transfer agent to obtain an aqueous dispersion, which is then neutralized with an alkaline agent. A wax composition in which a wax emulsion is mixed with the obtained neutralized aqueous dispersion, and the content of the neutralized aqueous dispersion in the mixture is 30% by weight or more of the total solid content as a solid content. 3. 95 of the particles of the resulting aqueous dispersion before neutralization.
The method for producing a sizing agent according to claim 1, wherein the weight percentage of the particles is 0.2 to 2.0 microns. 4. The method for producing a sizing agent according to claim 3, wherein the polymer contained in the resulting neutralized aqueous dispersion has a weight average molecular weight of 80,000 to 400,000. 5. 95 of particles of the resulting aqueous dispersion before neutralization
The sizing agent composition according to claim 2, wherein the weight percent or more has a particle size of 0.2 to 2.0 microns. 6. The method for producing a paste according to claim 5, wherein the weight average molecular weight of the polymer contained in the resulting neutralized aqueous dispersion is 80,000 to 400,000.