JPH0424288A - Polyester monifilament - Google Patents

Abstract

PURPOSE:To obtain filament excellent in abrasion resistance, etc., by curing a mixture of a specific silicon compound hydrolyzate with inorganic particles with a specified metallic compound and coating the surface of polyester monofilament with the resultant cured product through an adhesive layer to a specific thickness. CONSTITUTION:A silicon compound expressed by the formula (n is 1-3; R<1> is alkyl or alkoxyalkyl; n R<1> may be same or different; R<2> is 1-6C alkyl, etc.; R<3> is 1-10C alkylene, alkylene oxide, etc.; X is functional group including epoxy group) is hydrolyzed with an acidic solution and the resultant hydrolyzate is cured with a metallic compound selected from iron, chromium, aluminum, etc. The surface of polyester monofilament is then coated with the obtained cured product through an adhesive layer composed of a combination of preferably a copolymer of methyl methacrylate and styrene and trimethyl ether, etc., of hexamethylolmelamine applied to the surface thereof. Thereby, a coating layer having 0.5-20mum thickness is formed to afford monofilament excellent in abrasion resistance and flexing characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyester monofilament having excellent abrasion resistance and flexibility. More specifically, it relates to polyester monofilaments suitable for industrial uses such as marine materials such as fishing nets and fishing lines, and industrial materials such as brushes, belt cloths, filters, and papermaking nets.

[Prior Art] Generally, thermoplastic polyesters, such as polyethylene terephthalate, have excellent mechanical properties and chemical properties, and are widely used as molded products such as films and fibers.

However, when polyester monofilament is used in industrial applications, polyester monofilament is
Protrusions made of ceramics, plastics, etc. and fine particles made of these materials are susceptible to abrasion damage and wear, and therefore nets, fabrics, and the like made of polyester monofilament have the drawback of having a short product life.

Particularly in the paper manufacturing industry, acidic paper has traditionally been mainly produced, but as adverse effects such as oral deterioration have become more pronounced, there has been an active shift to acid-free paper. In the transition from acidic paper to neutral paper, the paper filler called filler was changed from talc to calcium carbonate, but since calcium carbonate has a higher hardness than talc, the wire (mesh net) used in the paper making process was ) has the operational drawback of shortening the service life of Polyester monofilament is generally used as the thread constituting this wire, which has the drawback of shortening the lifespan of the wire because it is abraded by calcium carbonate.

Conventionally, in order to improve the wear resistance of monofilaments made of synthetic resin, it is known to mix abrasive particles such as coke powder, bauxite alumina powder, diamond, and zirconia-based abrasives, but in the case of polyester monofilaments, Only local effects were observed because these particles were irregular in shape and particles aggregated strongly and were not uniformly dispersed.

Furthermore, JP-A No. 68-42976 proposes a method of applying a hard coating such as a polysiloxane coating agent or a crosslinked acrylic coating agent to the surface of a monofilament, but the surface coating is easy to fall off and does not last long. There was a problem with sexuality.

On the other hand, the surface hard coating technology of transparent plastics, such as plastic lenses, progressed, and
Publication No., JP-A-61-51036, JP-A-53-
No. 15743 and the like disclose a technique for coating a surface with a cured product of an organosilicon compound.

However, even if these cured products are coated on the surface of polyester monofilament, it is difficult to uniformly coat the surface, so only local improvements in abrasion resistance are observed, and the flexibility required for monofilament is also inferior. Met.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a polyester monofilament that has excellent abrasion resistance and flexibility.

[Means for Solving the Problems] The above-mentioned object of the present invention is to cure a mixture of a hydrolyzate of a specific silicon compound and inorganic particles with a specific metal compound, and to cure the cured product with an adhesive in advance. This can be achieved by coating the surface of a polyester monofilament to a specific thickness.

That is, the present invention cures a mixture of a hydrolyzate of a silicon compound represented by the following maximum formula % and inorganic particles with one or more metal compounds selected from iron, chromium, aluminum, cobalt, and titanium compounds. A polyester monofilament whose surface is coated with a cured product of .

The silicon compound in the present invention is represented by the above formula, and specific examples thereof include α-glycidoxypropyltrimethoxysilane and α-glycidoxypropylmethyldimethoxysilane.

It is essential that the silicon compound in the present invention contains an epoxy group. This is because during curing, which will be described later, a cured product with a ring-opening reaction of epoxy groups is produced, so even if this cured product is coated on a polyester monofilament, the flexibility is unlikely to decrease.

The hydrolyzate of a silicon compound in the present invention is produced by hydrolyzing the above-mentioned silicon compound with pure water or an acidic aqueous solution such as hydrochloric acid or sulfuric acid. This is usually carried out by adding an acidic aqueous solution to the silicon compound at once. It is also possible to control the hydrolysis rate by adjusting the addition rate or external temperature depending on the purpose.

During hydrolysis, alcohol, alkoxy alcohol, organic carboxylic acids such as acetic acid, etc. are produced, so hydrolysis can be carried out without a solvent. Furthermore, the silicon compound may be mixed with a suitable solvent and then hydrolyzed. Depending on the purpose, it is also possible to hydrolyze without a solvent and then remove an appropriate amount of the resulting alcohol, alkoxy alcohol, or organic carboxylic acid such as acetic acid, and water under heating and/or reduced pressure. It is also possible to substantially replace the solvent by subsequently adding a suitable solvent. As the solvent, various alcohols, esters, ethers, ketones, halogenated hydrocarbons, aromatic solvents such as toluene, etc. can be used depending on the purpose, and mixed solvents can also be used if necessary.

In the present invention, the hydrolyzate of the silicon compound is mixed with inorganic particles and hardened to further increase the hardness,
Improves wear resistance. Here, the inorganic particles refer to alumina, silica, titanium oxide, calcium carbonate, talc, kaolin, etc., but it is preferable to use inorganic particles having a hardness of calcium carbonate (Mohs hardness: 3) or higher.

Among them, alumina and silica are preferred because they have high reactivity with hydrolysates of silicon compounds. The blending amount of inorganic particles is as follows:
0 per 100 parts by weight of the silicon compound hydrolyzate
．． 0.01 to 20 parts by weight is preferred, more preferably 0.01 to 20 parts by weight.
05 to 15 parts by weight, particularly preferably 0.10 to 10 parts by weight.

If the amount is less than this, it will be difficult to increase the hardness of the cured product, and if the amount is more than this, the flexibility will decrease, which is not preferable.

Further, the average particle diameter of the inorganic particles is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less. If the average particle diameter exceeds 10 μm, the unevenness of the coating layer will increase, which is not preferable.

In the present invention, as a catalyst for curing the hydrolyzate of the silicon compound, one or more metal compounds selected from iron, chromium, aluminum, cobalt, and titanium can be used. In particular, aluminum compounds having the following structure are used in the present invention. can effectively achieve the objectives of

Au group
It is a residue of a ketoester compound. n is 0.1 or 2. ) Among such aluminum compounds, acetylacetone aluminum salt, aluminum dialkoxide monoalkyl acetoacetate, etc. are preferably used.

Specific examples of aluminum dialkoxide monoalkyl acetoacetate are as follows.

Aluminum-di-n-butoxide-mono-ethylacetoacetate, Aluminum-di-n-butoxide-mono-methylacetoacetate, Aluminum-di-1s
o-butoxide-mono-ethylacetoacetate, aluminum-di-1so-butoxide-mono-methylacetoacetate, aluminum-di-5ec-butoxide-mono-ethylacetoacetate, aluminum-di-1so-propoxide-mono-methylacetoacetate, aluminum selected from the group such as moo-di-methoxide-mono-methyl acetoacetate, aluminum-di-methoxide-cetoacetoacetate, aluminum-di-methoxide mono-methyl acetoacetate, and the like.

It is also possible to use a mixture of two or more of these including acetylacetone aluminum salt.

The amount of the catalyst added is 10 parts of the hydrolyzate of the silicon compound.
It is preferably 0.01 to 50 parts by weight, more preferably 0.05 to 10 parts by weight. If the amount is less than this, curing will be insufficient and it will be difficult to obtain sufficient wear resistance.
If the thickness is higher than this, hardening occurs rapidly, making it difficult to obtain a uniform thickness.

The thickness of the coating layer must be 0.5 to 20 μm, preferably 0.7 to 15 μm, and more preferably 0.8 to 12 μm. If it is thinner than 0.5 μm, the abrasion resistance is insufficient, and if it is thicker than 20 μm, the flexibility decreases when processing polyester monofilament into textiles, nets, etc., making it easy to crack, which poses a practical problem. .

It is necessary to provide an adhesive layer between the coating layer made of the cured product containing the inorganic particles and the polyester monofilament to be coated.

Here, the adhesive preferably has a high affinity for both the cured product and the polyester. Specific examples of components constituting the adhesive include a methacrylic acid ester homopolymer or a portion containing styrene, α-methylstyrene, p-
One or two types selected from aromatic vinyl monomers such as methylstyrene, mono- or dicarboxylic acids and acid anhydride monomers such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, and amide monomers such as acrylamide and methacrylamide. Melamine derivatives such as melamine, methylolmelamine, alkyl ether of methylolmelamine, isocyanate compounds such as tolylene diisocyanate and hexamethylene diisocyanate,
Examples include compounds containing one or more highly reactive compounds such as epoxy compounds such as phenylglycidyl ether and diglycidyl ether of bisphenol A.

Examples of preferred adhesive compositions include combinations such as copolymers of methyl methacrylate and styrene and trimethyl ether of hexamethylolmelamine.

The adhesive increases the adhesion between the base polyester monofilament and the above-mentioned coating layer, and suppresses peeling of the coating layer, so it is effective in improving wear resistance.

Although it is sufficient that the adhesive is only slightly attached to the surface of the polyester monofilament, the thickness of the adhesive layer is preferably 5 μm or less, more preferably 3 μm or less.

If the thickness of the adhesive layer exceeds 5 μm, it is not preferable because the adhesive layer itself will be destroyed due to abrasion and the abrasion resistance will decrease.

The polyester monofilament that coats the cured product is a continuous thread consisting of one single thread mainly composed of polyester, and the cross section of the thread can be round, triangular, square, regular polygonal, etc.

From the viewpoint of improving wear resistance, a round cross section is preferable because it is the least likely to wear out. The diameter of the cross section can be selected as appropriate depending on the application, but a range of 0.05 to 5 mm is often used, and 0.05 to 5 mm is often used. A range of 10 to 3 mm is most suitably applicable. If the diameter exceeds 5 mm, flexibility will be poor, which is not preferable.

The polyester constituting the polyester monofilament used for coating can be produced by a polycondensation reaction using a bifunctional component such as an aromatic dicarboxylic acid or its dialkyl ester and a glycol component as raw materials.
Particularly preferred is one mainly composed of polyethylene terephthalate. This polyester mainly composed of polyethylene terephthalate may be a homopolyester or a copolyester, and as a copolyester, for example, adipic acid, sebacic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, 5- Dicarboxylic acid components such as sodium sulfoisophthalic acid, polyvalent carboxylic acid components such as trimellitic acid and pyromellitic acid, oxycarboxylic acid components such as p-oxyethoxybenzoic acid, and tetramethylene glycol, hexamethylene glycol, diethylene glycol,
It may contain diol components such as propylene glycol, neopentyl glycol, polyoxyalkylene glycol, p-xylylene glycol, 1,4-cyclohexane dimetatool, and 5-sodium sulforesorcin.

The polyester monofilament of the present invention can be obtained, for example, by the following novel method.

First, a polyester monofilament is obtained by ordinary melt spinning and drawing methods. The monofilament is immersed in an adhesive liquid and then dried by heating to adhere the adhesive to the surface of the monofilament. Furthermore, the monofilament to which this adhesive is attached is immersed in a coating liquid that is a mixture of a hydrolyzate of a silicon compound, inorganic particles, and a catalyst and maintained at 40°C or lower, and then the polyester monofilament to which the coating liquid is attached is heat-treated,
Surface harden. If the temperature of the coating liquid exceeds 40 DEG C., the curing reaction progresses and the viscosity of the coating liquid increases by -L, making it difficult to uniformly coat the polyester monofilament with a thickness of 20 .mu.m or less.

Therefore, the temperature at which the hydrolyzate of the silicon compound, the inorganic particles, and the catalyst are mixed, and the storage temperature of the coating liquid are 4.
The temperature is preferably 0°C or less.

The viscosity of the coating liquid is preferably 1000 centipoise or less (measured with a B-type viscometer at 20° C.), and a solvent may be used for this purpose.

Furthermore, as a method for applying the adhesive and coating liquid, a spraying method and a coating method can also be used. It is also possible to apply the adhesive and the coating liquid during the polyester monofilament manufacturing process, for example during the drawing process and heat setting process.

The practical heat treatment temperature (curing temperature) of the monofilament to which the coating liquid is attached is 50 to 250°C, and the curing time varies depending on the treatment temperature, but can be appropriately selected from several seconds to several minutes.

Furthermore, in order to improve the properties of the polyester monofilament, a viscosity modifier for controlling the thickness may be included in the coating liquid as necessary. Further, hydrolysates of other silane compounds can also be contained within a range that does not impair the properties of the polyester monofilament.

The polyester monofilament of the present invention is suitably used in applications requiring abrasion resistance, such as brushes, belts, filters, and papermaking nets.

In particular, when used as a papermaking net, it is suitable because wear on calcium carbonate can be significantly suppressed.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, the physical property evaluation method in Examples is as follows.

(1) Measurement of diameter The monofilament was directly measured at 6 points at 5 cm intervals using a dial gauge (manufactured by Amagasaki Seisakusho), and the average value was determined.

(2) Measurement of coating thickness The diameter before and after coating was measured using a dial gauge, and calculated using the following formula.

Coating thickness - (D+Do)/Six points were measured at intervals of 25 cm, and the average value was taken as the thickness. (However, Do is the diameter before coating, and Dl is the diameter after coach ink.) The thickness of the adhesive layer was also measured in the same manner.

(3) Evaluation of wear resistance A weight of 100 g is attached to the tip of a polyester monofilament, and 0.5 weight of calcium carbonate powder "Nisscalon"#800 manufactured by Sankyo Seifun Co., Ltd. is placed in a ceramic cylinder with a diameter of 60 mm rotating at 1500 rpm. % water suspension was brought into contact while dropping, and the time until cutting was measured. This operation was performed on six monofilaments, and the average was taken as the cutting time.

The longer the cutting time, the better the wear resistance.

(4) Evaluation of Flexibility The polyester monofilament was bent until the radius of curvature was 5II1 m, and the bent portion was observed under a microscope. Poor flexibility can be confirmed by cracks in the coating layer and whitening.

Example 1 (1) Manufacturing method of polyester monofilament for coating Polyethylene terephthalate having an intrinsic viscosity of 0.7 LO and a softening point of 260° C. is subjected to a melt extrusion spinning machine equipped with a nozzle with a hole diameter of 1.5 mm, and after melt spinning, it is cooled. And then 1 more
A polyester monofilament having a diameter of 210 μm was obtained by stretching 5.7 times at 20° C. and setting the relaxation heat at 190° C. and 0.9 times.

(2) Method for preparing adhesive liquid and applying adhesive Methyl methacrylate (70 mol%) and styrene (30 mol%)
), 1 part of trimethyl ether of hexamethylolmelamine, 0.2 parts of sodium dodecylbenzenesulfonate as a surfactant, and 91.8 parts of water were mixed with stirring to obtain a homogeneous emulsion adhesive liquid. . The polyester monofilament obtained in (1) was immersed in this adhesive solution at a constant speed of 0.4 m/min, then pulled up at the same speed and passed through a 1 m long heating tube at 150°C (2,5 m/min). ) Continuously dried to obtain a polyester monofilament with adhesive attached.

(3) Preparation of γ-glycidoxypropyltrimethoxysilane hydrolyzate (component (A)) 236 parts of γ-glycidoxypropyltrimethoxysilane was charged into a reactor equipped with a rotor, and a magnetic stirrer was used. While vigorously stirring, 72 parts of a 0.01N aqueous hydrochloric acid solution was added at once. Immediately after addition, the solution was opaque and heterogeneous, but within a few minutes after addition, it became a homogeneous, colorless and transparent solution while generating heat.

Stirring was continued for an additional hour and then stopped. The solid content of the obtained hydrolyzate (2
The residual amount (residue after standing for a period of time) was 60% (this hydrolyzate is hereinafter abbreviated as H-GPS).

As component (A) prepared in <3) above, H-GPs i
Add 2 parts of silica with an average particle diameter of 0.5 μm as inorganic particles (component (B)) and 3 parts of acetylacetone aluminum salt as a curing catalyst (component (C)) at 20°C to a solution containing 0. A voice coating liquid was obtained. Immediately after preparing the coating solution, 0.4 g of the polyester monofilament with the adhesive obtained in (2)
After immersing at a constant speed of m 2 /min, the sample was pulled up at the same speed and continuously cured while passing through a heating tube of 1 m length at 160° C. (2.5 minutes).

This polyester monofilament was subjected to an abrasion resistance test and a flexibility test.

The results are summarized in Table 1.

Comparative Example 1 A polyester monofilament was obtained in the same manner as in Example 1 except that no adhesive was attached, and an abrasion resistance test and a flexibility test were conducted. The results are summarized in Table 1.

Example 2 Polyester monofilament was added to the adhesive solution prepared in Example 1. A polyester monofilament was obtained in the same manner as in Example 1 except that it was immersed at a speed of On+/min and the thickness of the adhesive layer was changed, and was subjected to an abrasion resistance test and a bending test. The results are summarized in Table 1.

Example 3 Immediately after preparation, 1.0% adhesive-attached polyester monofilament was added to the coating solution prepared in Example 1. Om/m1
A polyester monofilament was obtained in the same manner as in Example 1, except that the dipping was performed at a speed of n and the thickness of the coating layer was changed, and a wear resistance purity test and a bending test were conducted. The results are summarized in Table 1.

Example 4.5 2 alumina with an average particle size of 0.8 μm was used as the component (B).
After obtaining a polyester monofilament in the same manner as in Example 1 except that 1 part (Example 2) and 2 parts of titanium oxide (Example 3) with an average particle size of 0.7 μm were blended, the polyester monofilament was subjected to an abrasion resistance test and a bending test. The test was conducted and the results shown in Table 1 were obtained.

Comparative Example 2 A coating solution having the same composition as in Example 1 was left at 60° C. for 24 hours.

The viscosity of this coating liquid was 1500 centipoise, and using this coating liquid, a polyester monofilament was obtained in the same manner as in Example 1, and an abrasion resistance test and a bending test were conducted.

The results are summarized in Table 1.

Comparative Example 3.4 Example 1 for a coating liquid with a different composition shown in Table 1
A polyester monofilament was obtained in the same manner.

The obtained monofilament was subjected to an abrasion resistance test and a bending test in the same manner as in Example 1.

The results are summarized in Table 1.

Comparative Example 5.6 Using methyltrimethoxysilane as the silicon compound,
After hydrolyzing in the same manner as in Example 1 except that 136 parts of methyltrimethoxysilane and 54 parts of a 0.1N aqueous hydrochloric acid solution were used, 3 parts of acetylacetone aluminum salt (Comparative Example 5) and 3 parts of sodium acetate (Comparative Example 5) were added. Example 6)
was added to prepare a coating solution.

A polyester monofilament was obtained in the same manner as in Example 1, and an abrasion resistance test and a bending test were conducted.

The results are summarized in Table 1.

While the polyester monofilaments obtained in Examples 1 to 5 have good abrasion resistance and flexibility, without the adhesive layer (Comparative Example 1) the abrasion resistance is poor and the thickness of the coating layer is If it is too high (Comparative Example 2), the abrasion resistance becomes very good, but the flexibility deteriorates and cracks easily occur and whitening occurs. Compared to Example 1, those that do not contain inorganic particles (Comparative Example 3) and those that use another curing catalyst as component (C) (Comparative Example 4) have shorter cutting times and inferior wear resistance. Met.

In addition, when a hydrolyzate of methyltrimethoxysilane containing no epoxy group and silica were used, and acetylacetone aluminum salt was used as a curing catalyst (Comparative Example 5)
Because the curing did not progress, the abrasion resistance was poor, and when sodium acetate was used as a curing catalyst (Comparative Example 6), the abrasion resistance was improved by curing, but the flexibility was poor.

(Margin below) [Effects of the Invention] The surface of the polyester monofilament of the present invention is coated with a cured product obtained by curing a mixture of a hydrolyzate of a specific silicon compound and inorganic particles with a specific metal compound via an adhesive layer. This increases the adhesion between the polyester monofilament and the coating layer, resulting in good abrasion resistance and excellent flexibility, making it excellent in processability into fabrics, nets, etc.

The polyester monofilament of the present invention can be used in all fields where the above properties are required, but its effects will be even more apparent when applied to the papermaking process network in the production of neutral paper, which is prone to abrasion due to inorganic particles such as calcium carbonate. . In this case, since it has good abrasion resistance and excellent flexibility, it is possible to operate papermaking at high speed for a long time.

Claims (2)

[Claims] (1) General formula below ▲ There are mathematical formulas, chemical formulas, tables, etc. Good too. R^2 is C_1 to C_6 alkyl or aryl group, R^3 is C_1 to C_1_0 alkylene or alkylene oxide or polyalkylene oxide, X
is a functional group containing an epoxy group. ] A cured product obtained by curing a mixture of a hydrolyzate of a silicon compound and inorganic particles shown in the formula with one or more metal compounds selected from iron, chromium, aluminum, cobalt, and titanium compounds is cured through an adhesive layer. A polyester monofilament whose surface is coated, wherein the coating layer has a thickness of 0.5 to 20 μm. (2) The polyester monofilament according to claim (1), which is used as a constituent yarn of a papermaking net.