JPH01124681A - Thermal stabilization of epoxy ring - Google Patents

Abstract

PURPOSE: To provide a method for thermally stabilizing an epoxy ring itself of multivalent epoxy compound used as a treating agent for polyester fibers, after being incorporated with a specific compound, useful for greatly improving adhesion of the polyester fibers to rubber by attaching the agent to the fibers being thermally treated for spinning or drawing. CONSTITUTION: This method is for thermal treatment of polyester fibers at 200 deg.C in the absence of a catalyst during the spinning/drawing process, and thermally stabilizes an epoxy ring of multivalent epoxy compound for a treatment agent for the fibers, wherein the treatment agent, containing the epoxy compound having a molecular weight of 200 to 3000 (preferred example: aliphatic polyglycidyl ethers) at 30 wt.% or more, is mixed with a spinning or drawing oil, or separately attached to the fibers. The treatment agent is incorporated, prior to the thermal treatment of the fibers, with 0.05 to 5 wt.% of a compound having a hindered phenol group shown by the formula (R' and R" are each H, or a 1-4C lower alkyl; and Z is an organic residue), to thermally stabilize the epoxy group, leave the epoxy compound reactive and at a high concentration, and thereby greatly improve adhesion of the fibers to rubber by the RFL treatment. The treatment agent may be further incorporated with a thioester compound (preferred example: thiodipropionate ester).

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for thermally stabilizing an epoxy compound, and more particularly, to a method for thermally stabilizing an epoxy compound, which has been proposed for a long time to improve the adhesiveness of polyester yarn. Catalyst-free drawn and heat-treated polyester yarns are prepared by mixing the epoxy compound into the spinning oil, applying it separately, or mixing it into the drawing oil before and after drawing, or applying it separately and then heat treating it. The present invention relates to a method for stabilizing epoxy rings in which the reactive epoxy compound remains on the drawn yarn after heat treatment during the yarn spinning process without being changed as much as possible.

<Conventional technical fields> Polyester fibers are generally manufactured by melt spinning, have high strength, a high Young's modulus, and have good dimensional stability, so they are used as reinforcement for rubber structures such as tire cords, conveyor belts, and ■-belts. Although it has favorable physical properties as a fiber, since the surface of the polymer is inert, sufficient adhesion cannot be obtained with only a resorcinol formalin latex dispersion (hereinafter referred to as RFL) for the same purpose as polyamide fibers. Specifically, various methods and compounds have been used for a long time to improve the adhesion between polyester fibers and rubber. Among these, the most typical compound is a method in which a polyvalent epoxy compound is mixed with a spinning oil or drawing oil in the presence of a catalyst, or it is separately attached to the yarn in the spinning or drawing process and then heat-treated. In other methods, polyester fibers are coated with a polyvalent epoxy compound in the absence of catalysts, stretched and heat-treated, then wound, twisted into cords, and then reacted with isocyanate, etc. A method has been proposed in which a blocked isocyanate or/and an ethylene urea compound that reacts with an epoxy compound and hardens is mixed into the RFL processing agent during processing. In all of these methods, it is necessary that reactive epoxy groups remain on the fiber, and the higher the concentration of reactive epoxy groups that can remain, the better the rubber adhesion. become. However, highly reactive polyvalent epoxy compounds cause thermal polymerization when heat-treated on fibers, and when used in combination with spinning oil or drawing oil, unexpected results may occur when heat-treated. The weight loss of externally active epoxy compounds is often significant. This is true even if a high molecular weight polyvalent epoxy compound that does not volatilize during heat treatment is used.

<Object of the Invention> The object of the present invention is to apply a polyvalent epoxy compound to polyester fibers in the absence of a catalyst, and after drawing and heat treatment, the polyvalent epoxy compound remains on the yarn in a state with as much reactivity as possible. It's about letting people know.

<Structure of the invention> That is, the present invention has an average molecular weight of 200 or more to 3
When a fiber treatment agent containing 30% or more of a polyepoxy compound of 000 or less is attached to polyester fibers and heated at 200°C or higher in the absence of a catalyst, the treatment agent may be of the general formula (
At least one of the compounds shown in 1) containing a compound having at least one hindered phenol group in the molecule
Either 0.05 to 5.0% (by weight) of the seed is added to the epoxy compound to heat stabilize the epoxy ring, or at least one of the hindered phenol compounds and a thioester compound are added. This is intended to protect the epoxy ring from changes caused by heating.

The target polyester fiber in the present invention refers to polyethylene terephthalate having a degree of polymerization that allows fiber formation or a copolymer polyester that can form fibers and in which at least 80% of all structural units are ethylene terephthalate, and the intrinsic viscosity of the polyester is (0-chlorophenol solution, measured at 25°C) 0.5 to 1.2 is preferred.

In addition, the epoxy compounds used in polyester fibers, which are the object of the present invention, are not particularly limited, but include known polyvalent epoxy compounds that have been commonly tried for polyester fibers, such as ethylene glycol, glycerin,
Pentaerythritol, sorbitol, polyethylene glycol, dicarboxylated or multimeric products of glycerin, polyglycidyl ethers of aliphatic polyhydric alcohols, triglycidyl isocyanurate having a heterocyclic ring, and other aromatic aliphatic glycidyl ethers, etc. Epoxy compounds having a glycidyl ether group are used alone or in combination. However, from the viewpoint of ease of use, it is preferable to use those that are easily soluble in water or aliphatic polyglycidyl ethers that are easily dispersible in water. These epoxy compounds are used separately or in combination with a spinning oil or a drawing oil in the spinning or drawing process.

On the other hand, specifically, the compound having at least one hindered phenol group in the molecule represented by general formula (1) is 1,3.5-tris(4-t-butyl-3-
Mention may be made of hydroxy-2,6-dimethylbenzyl)isocyanuric acid.

These compounds have long been known as antioxidants, and are often used as effective heat stabilizers to prevent heat deterioration of polymeric substances, and to prevent smoke generation when heated and thermal decomposition of oils. Although there are some proposals for using it to prevent volatility, as in the present invention, it is said that it is effective in suppressing the thermal polymerization of the epoxy ring itself and reducing the thermal reaction of the epoxy ring with other components. Nothing has been reported so far.

In general, in the present invention, when a known sulfur-containing ester compound is used in combination with the addition of the hindered phenol compound, the effect can be further increased. That is, the thioester compound is already well known as a heat stabilizer for polymers, and esters of thiodipropionic acid are preferably used. i.e. dilaurylthiodipropionate.

Examples include distearylthiodipropionate, dioleylthiodipropionate, diisostearylthiodipropionate, and various other compounds are synthesized with only alkyl groups, such as modified alkylthiodipropionates. The present invention is not limited to any ester compound of thiodipropionic acid.

These thioester compounds, in addition to their effects in the present invention, are smoothing agents for fibers, that is, heat-resistant smoothing agents themselves, and are useful in terms of lubrication, so their combined use is suitable. Therefore, there is no particular restriction on the thiodipropionate-based ester compound (usually it can be used in the range of 5 to 75%), but it is better to mix it in a larger amount in terms of heat resistance.

The hindered phenol compound that is the object of the present invention is solid and has a relatively high melting point, and it is not necessary to add a large amount from a functional standpoint, and the amount of the hindered phenol compound that is the object of the present invention is 0.05 to 5.0% relative to the epoxy compound.
% (weight) may be added. If it is less than 0.05%, the effect will be small, and if it exceeds 5.0%, the stability of the emulsion in the spinning oil or drawing oil used together will be poor, which is not preferable. Desirably 0.1 to 3.0
A sufficient effect can be expected within the range of about %.

In addition, in order to mix these stabilizers into a spinning oil or drawing oil, since they do not dissolve as they are, they must be mixed and dissolved in advance in the spinning oil base or drawing oil base used together with the epoxy compound, or used. Either method may be used since it can be easily mixed by heating and dissolving it in the polyvalent epoxy compound in advance.

The spinning oil or drawing oil containing 30% or more of the epoxy compound thus obtained is applied to the polyester fiber before it is heat treated. Although not particularly limited in the present invention, the method for attaching the epoxy compound may include a method in which the epoxy compound is included in the spinning oil, a method in which the epoxy compound is attached separately from the spinning oil, or a method in which the epoxy compound is attached in the drawing process. It may be applied at any step before the polyester fibers are heat treated. However, it is preferable to attach it to undrawn yarn and then subject the undrawn yarn to drawing and heat treatment in the same manner as ordinary polyester fibers are drawn and heat treated. Stretching is usually carried out by a factor of 5.0 to 5.8 and then heat treated at a temperature of 180'C1, preferably 200C or higher. As described above, the epoxy compound-containing oil agent used to improve adhesiveness contains at least 30% or more of the epoxy compound, but in order to obtain high-quality adhesiveness, it is especially used in a mixture of 50% or more. Further, the amount of adhesion may be determined by any of the commonly known methods, such as an oiling roller method, a spray method, a dipping method, and a metering method. The adhesion amount is 1100 fibers (0.25 to 7
About 0.4%, of which the epoxy compound is 0.
．． It is preferable that the amount is about 1 to 0.2% (by weight).

<Actions and Effects of the Invention> As described above, the present invention is applicable to all conventionally known antioxidants, which are effective as heat stabilizers for preventing heat deterioration of polymeric substances. Hindered phenol, which is known to be used to prevent oils from smoking when heated and from becoming volatile due to thermal decomposition, has a completely different function: suppressing the thermal polymerization of the epoxy ring itself and preventing other epoxy rings from forming. This was done based on new knowledge that it is effective in reducing thermal reactions with components, and this allows for high concentrations of reactive epoxy groups even on fibers after heating. Since it can remain, it is possible to provide a treatment system with excellent rubber adhesion.

In addition, regarding the quantitative determination of the particularly reactive epoxy part of the epoxy compound attached to polyester fibers, the yarn obtained by deoiling with cyclohexane and concentrating the cyclohexane from the stretched and heat-treated yarn was used with the usual epoxy quantitative method. Three methods were used, including the hydrochloric acid dioxane method, the sodium sulfite method, and the hydrobromic acid wood vinegar method, and the stability of the epoxy ring was determined and confirmed from the beginning before heat treatment.

Of course, when the epoxy compound was used alone, when the oil agent and the epoxy compound were used together, and when the epoxy compound was used in combination with the oil agent, quantitative measurements were carried out before and after heating for the extracts from the threads, and the rate of change was examined.

Measurement of the rate of change of epoxy rings - 1 (1) Weigh 1 g of a sample made of a commercially available epoxy compound (100%), place it in a 4 cm diameter dish, and dry with hot air at 200°C for 60 minutes and 90 minutes. The sample was heated in a machine, and after it had cooled down, it was dissolved in dioxane and carried out using the hydrochloric acid-dioxane method which is usually carried out with 0.2 Nl-(α.At the same time, the epoxy oxygen content of the immature epoxy compound was measured. The rate of change was calculated from the percentage of Epon rings before and after heating.

(2) A sample consisting of a commercially available epoxy compound (ioo%) and a spinning oil were mixed so that the ratio of the epoxy compound to the spinning oil was 50.
150 and 70/30, and the rate of change was determined in the same manner as in (7).

Measurement of the rate of change of epoxy rings - 2 In the case of water droplets, the yarn 500 () obtained after spinning and drawing of polyester and heat treatment was deoiled using cyclohexane according to the commonly known method for measuring the oil adhesion rate, and then treated with a Soxhlet extractor.
After the cyclohexane was distilled, the epoxy oxygen percentage was determined using the hydrochloric acid-dioxane method, and the rate of change was determined from measurements before and after the heat treatment.

The present invention will be further explained in detail with reference to Examples below, in which (%) and parts all indicate parts by weight or weight percent.

Note that the examples used in this embodiment are limited in type, but are not limited thereto in any way.

The epoxy compounds and compounds having a hindered phenol group in the molecule that were used in the examples are listed below.

[E-1 diglycerin polyglycidyl ether (Nagase Sangyo, trade name Denacol EX-421) as epoxy compounds E-2 bisphenol polyglycidyl ether (Shell Co., trade name Epicote 828) [2] A as a hindered phenol compound -1L3,5-tris(4-1-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid (
Cyanamide Co., Ltd., Cyanox 1750) was used.

Example 1 and Comparative Example 1 Using bisphenol type polyglycidyl ether (E-2), the above-mentioned A
Samples were prepared with 2□5% of -1 added and without addition, 1.0 g of each was collected in a stainless steel dish, heat treated at 200°C for 60 minutes and 90 minutes, and before and after heat treatment, respectively.
Excursion using the hydrochloric acid-dioxane method, each epoxy oxygen (%
) and how it changes before and after heating was determined. The results are shown in Table-1.

Table 1 *The rate of change was calculated based on the epoxy oxygen (%) at room temperature as 100.

Example 2. Comparative Example 2 Diglycerol polyglycidyl ether (E-1> was used in the same manner as in Example 1, the amount of hindered phenol compound (A-1> was changed as shown in Table 2), and thiodipropionic acid We determined how the results would change depending on whether or not dioleyl thiodipropionate was added as an ester compound.The results are shown in Table 2.

Example 3. Comparative Example 3 Using diglycerin diglycidyl ether (E-1), dioleyl adipate (20 parts) and isotridecyl stearate (20 parts) as a spinning oil base for polyester fibers were used.
POE (30 parts) was added as an emulsifier to a smoothing agent consisting of POE (30 parts).
lauryl ether (15 parts > mol), POE (12
mol) Castor oil ether (15 parts>, POE (5 mol)
Nonylphenyl ether (10 parts>, POE (4 mol)
Using formulation (8) consisting of oleyl alcohol ether (10 parts), the ratio of E-1 and CB) was blended to 50150 or 70/30 to produce an epoxy compound-containing oil agent, and for each, A-1. We determined how the residual rate of epoxy rings changes depending on the presence or absence of epoxy rings. The results are shown in Table 3.

Example 4. Comparative Example 4 Polyethylene terephthalate fiber yarn made into yarn from a 0.4 mmφ x 250H nozzle ([η]=0.90)
(solvent, 0-chlorophenol, temperature 35°C) is wound onto a bobbin at a speed of 400 m/min, but before being wound, the epoxy compound E-1 used in Example 3 and (8) as a base oil agent are During spinning, a 10% aqueous emulsion prepared at a mixing ratio of 80/20 was applied using an oiling roller, and then stretched and
Heat treatment was performed. That is, the stretching was carried out using a stretching machine capable of two-stage heating stretching, 3.5 times at 78°C, then 180°C.
Stretch it to 5.8 times in the first and second stages, and
Heat setting was performed at 0° C. to obtain a drawing heat treatment system of 1500 denier/250 filament. At this time, E −1/
B=80/20 with and without addition of hindered phenol A-1 at 2.56% based on the epoxy compound were simultaneously obtained, and the yarn thus obtained was deoiled with cyclohexane. The epoxy oxygen (%) of the deoiled components was measured, and the amount of epoxy oxygen added to A-1 was 6.6%, while that of the yarn without the addition was 4.2%. there were.

Claims (2)

[Claims] (1) When a fiber treatment agent containing 30% or more of a polyvalent epoxy compound with an average molecular weight of 200 to 3000 is attached to polyester fibers and heat-treated at 200°C or higher in the absence of a catalyst, the following general treatment agents may be used as the treatment agent: As shown by formula (1),
At least one hindered phenol group in the molecule ▲ There is a mathematical formula, chemical formula, table, etc. ▼... (1) [However, R' and R'' are hydrogen atoms or lower alkyl groups having 1 to 4 carbon atoms, and Z is another represents an organic residue.] to the epoxy compound at a rate of 0.05
A method for thermally stabilizing an epoxy ring, characterized by using an epoxy ring containing 5.0% (by weight) of an epoxy ring. (2) When a fiber treatment agent containing 30% or more of a polyvalent epoxy compound with an average molecular weight of 200 to 3000 is attached to polyester fibers and heat-treated at 200°C or higher in the absence of a catalyst, the treatment agent contains at least At least one compound having one or more hindered phenol groups
A method for thermally stabilizing an epoxy ring using a thioester compound in combination with 0.05 to 5.0% (by weight) of a seed based on the epoxy compound.