JPH0693109A - Spherical thermoset polyester particle and production thereof - Google Patents

Abstract

PURPOSE:To provide spherical polyester particles having a high degree of sphericity and excellent resistance to chemicals, heat, and light. CONSTITUTION:The particles are made of a polyester obtained mainly from a diol component and a dicarboxylic acid component comprising at least 60mol% aromatic dicarboxylic acid and thermally cured with an ester-forming compound having a functionality of 3 or higher. They have an average particle diameter of 0.1-500mum and a ratio of the major to the minor axis diameter of 1.0-1.2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thermosetting polyester spherical particles having a substantially spherical shape and excellent in heat resistance, weather (light) resistance and chemical resistance, and a process for producing the same.

[0002]

2. Description of the Related Art Conventionally, polymer particles have been widely used as antiblocking agents, matting agents, organic fillers, thickness gap adjusting agents, electronic materials and the like. As the polymer particles used for such an application, a granular thermoplastic polymer obtained by suspension polymerization of an ionic group-containing polyester and an ionic group-containing vinyl monomer (Japanese Patent Laid-Open No. 3-212444) ) And a granular thermosetting resin obtained by suspension polymerization of a phenol resin (JP-A-61-258819) and the like are known. Of these,
The granular thermoplastic resin cannot be used as an organic filler because it is melted by heat, and cannot be used in a field requiring heat resistance and chemical resistance. On the other hand, the granular thermosetting phenolic resin has good heat resistance, but since the discoloration is remarkable,
It could not be used in a field requiring light resistance.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the drawbacks of conventional polymer particles, and improves heat resistance and weather resistance (light).
The present invention aims to provide a polyester spherical particle having excellent properties and chemical resistance, and a method for producing the same.

[0004]

Means for Solving the Problems As a result of intensive research to solve the above problems, the present inventor has found that thermosetting polyester spherical particles achieve the object,
The present invention has been reached.

That is, the gist of the present invention is as follows. 1. A polyester mainly composed of a dicarboxylic acid component and an diol component in which an aromatic dicarboxylic acid accounts for 60 mol% or more is crosslinked with a trifunctional or higher functional ester-forming compound and is thermoset, and has an average particle size of 0.1. ~ 500μ
m, thermosetting polyester spherical particles having a ratio of major axis to minor axis of 1.0 to 1.2. 2. A polyester resin A mainly composed of a dicarboxylic acid component having an aromatic dicarboxylic acid content of 60 mol% or more, a diol component and a diol component is treated under an inert gas atmosphere with the formula (1)
In the molten state at a temperature T (° C) that satisfies
A trifunctional or higher functional ester-forming compound having a melting point t (° C.) satisfying the above condition and soluble in the polyester resin A is added in an amount of 0.5 to 10 mol% to the dicarboxylic acid component constituting the polyester resin A in powder form, A method for producing thermosetting polyester spherical particles, which comprises reacting under stirring to obtain a resin composition containing thermosetting spherical polyester, and separating the thermosetting spherical polyester. 150 ≦ T ≦ 300 (1) T-100 ≦ t (2)

The present invention will be described in detail below. The spherical particles of the present invention are trifunctional or higher functional ester-forming compounds that are polyesters mainly composed of a dicarboxylic acid component in which an aromatic dicarboxylic acid accounts for 60 mol% or more and a diol component.
(Hereinafter, referred to as a cross-linking agent.) It is composed of polyester which is cross-linked by heat and is cured.

The dicarboxylic acid component is required to have an aromatic dicarboxylic acid content of 60 mol% or more. If the proportion of the aromatic dicarboxylic acid is less than 60 mol%, the heat resistance will be poor.
Not practical. Specific examples of the aromatic dicarboxylic acid include:
Terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,
4'-diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and the like can be mentioned.

40 mol% with the aromatic dicarboxylic acid component
An aliphatic dicarboxylic acid component can be used in combination in the following amounts, and specific examples of the aliphatic dicarboxylic acid include adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexadecanedioic acid, eicosanedioic acid and the like. .

On the other hand, specific examples of the diol component include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol and 1,6-hexanediol. , 1,9-nonanediol, diethylene glycol, dipropylene glycol, 2,2,1-trimethyl-1,
3-pentanediol, 1,4-cyclohexanedimethanol, spiroglycol, p-xylyleneglycol,
Ethylene oxide adduct of p-xylylene glycol, ethylene oxide and / or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A
Ethylene oxide and / or propylene oxide adduct, polyethylene glycol, polytetramethylene glycol and the like.

Incidentally, as a component constituting the polyester, a small amount of an oxycarboxylic acid component such as p-hydroxybenzoic acid may be contained in addition to the dicarboxylic acid component and the diol component, within a range not causing gelation of the polyester.
A functional or higher ester-forming compound may be contained.

Specific examples of the crosslinking agent include acid components such as trimellitic acid, trimellitic anhydride, trimesic acid, pyromellitic acid and pyromellitic dianhydride, and alcohol components such as trimethylolpropane and pentaerythritol. To be Of these, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride and pentaerythritol are particularly preferably used because they have a high melting point and do not melt immediately.

The particles of the present invention have a particle size of 0.1 to 500 μm,
It is necessary that the ratio of the major axis to the minor axis is 1.0 to 1.2. It is difficult to obtain particles having a particle size of more than 500 μm and good sphericity, and particles having a particle size of less than 0.1 μm are not preferable because classification becomes difficult and the operability of the subsequent process deteriorates. Further, the ratio of the major axis to the minor axis is preferably 1.0 to 1.1, and particles having a value exceeding 1.2 are not practical as spherical particles lacking in sphericalness.

Next, the method for producing the spherical particles of the present invention will be described. First, the polyester resin A mainly composed of the above-mentioned dicarboxylic acid component and diol component is produced by a conventional method. For example, the polyester raw material is put into an esterification reaction can, and after being replaced with nitrogen gas, 0.5 to 5.0 kg / cm ²
Under the nitrogen gas pressure control of 1, raise the temperature to 190-270 ℃ and
Perform the esterification reaction for ~ 3 hours. The resulting esterified product is transferred to a polymerization reaction vessel and subjected to polycondensation reaction at a temperature of 200 to 300 ° C. under a reduced pressure of 1 Torr or less until a desired intrinsic viscosity is reached (0.5 to 5 hours), and a polyester resin is obtained. Get A. The polycondensation reaction is usually performed in the presence of a catalyst, and examples of the polycondensation reaction catalyst include compounds of metals such as antimony, germanium, tin, titanium, and cobalt, sulfosalicylic acid, and o-sulfobenzoic anhydride. The organic sulfonic acid compound of is used. Then, the polyester resin A is heated in an inert gas atmosphere at a temperature T (° C.) that satisfies the above formula (1).
And a melting point t satisfying the above formula (2).
A spherical polyester which has a temperature (° C.) and is dissolved in the polyester resin A in an amount of 0.5 to 10 mol% with respect to the dicarboxylic acid component constituting the polyester resin A in powder form and reacted by stirring to be thermoset A resin composition containing is obtained.

At this time, it is necessary that the temperature T be in a range (150 to 300 ° C.) that satisfies the above formula (1). This temperature is selected according to the melting point of the polyester resin A,
When this temperature is lower than 150 ° C, the polyester resin A and the crosslinking agent do not react with each other, and thus thermosetting spherical particles cannot be obtained. On the other hand, when the temperature exceeds 300 ° C, the polyester resin A is thermally decomposed during the reaction, which is satisfactory. No heat-cured spherical particles can be obtained.

Further, the cross-linking agent must have a melting point t (° C.) satisfying the above formula (2). If the amount is out of this range, the compound quickly melts after adding the cross-linking agent, and thus thermosetting spherical particles cannot be obtained.

It should be noted that 3 having a melting point not satisfying the formula (2)
The functional or higher ester-forming compound may be added at the same time as long as the polyester resin is not gelled.

The cross-linking agent must be one that is soluble (compatible) in the polyester resin A, and a non-soluble compound will not react with the polyester resin A, so that thermosetting spherical particles cannot be obtained. .

The amount of the crosslinking agent added is required to be in the range of 0.5 to 10 mol% with respect to the dicarboxylic acid component constituting the polyester resin A. If this amount is less than 0.5 mol%, a practical amount of heat-cured spherical particles will not be formed.
On the other hand, if it exceeds 10 mol%, the polyester resin will gel without forming spherical particles.

The cross-linking agent needs to be added to the molten polyester resin A and reacted under stirring. The degree of stirring is such that it can be finely dispersed before the cross-linking agent melts and reacts with the polyester resin A. Good.

When the polyester resin A and the cross-linking agent are reacted as described above, a resin composition composed of thermosetting spherical particles and non-thermosetting thermoplastic resin is produced.
The obtained resin composition is discharged from a reaction can onto, for example, a polytetrafluoroethylene sheet in a sheet shape and allowed to cool, and thermosetting spherical particles are taken out. To take out the thermosetting spherical particles, the thermoplastic resin portion may be removed. For example, a liquid heated to a temperature at which the thermoplastic resin portion is melted or higher is filtered, or the thermoplastic resin portion is treated with an organic solvent such as dioxane. The solution in which is dissolved may be filtered.

The particle size and sphericity of the particles of the present invention are the intrinsic viscosity of the polyester resin A, the particle size of the cross-linking agent powder, the reaction temperature when the polyester resin A and the cross-linking agent are reacted and the melting point of the cross-linking agent. It can be controlled by adjusting the stirring conditions and the like.

[0022]

[Function] The particles of the present invention have a crosslinked structure (three-dimensional network structure).
Since it is composed of an aromatic polyester having
It is insoluble and infusible and has excellent heat resistance and chemical resistance. Further, the spherical particles can be obtained by the method of the present invention by adding a high-melting cross-linking agent to the polyester resin A in a molten state so that the cross-linking reaction with the polyester resin A on the surface of the cross-linking agent before the cross-linking agent melts. However, it is presumed that the interface is made incompatible.

[0023]

EXAMPLES Next, the present invention will be described in detail with reference to examples. The characteristic values and the like were measured or evaluated as follows. (a) Melting point The melting point was measured with a differential scanning calorimeter (DSC-2 type manufactured by Perkin Elmer Co., Ltd.) at a temperature rising rate of 20 ° C./min. (b) Particle size The particle size was measured using an image processing device (Luzex III U manufactured by Nireco). (c) Heat resistance It was left for 10 minutes in an electric furnace with a temperature of 500 ° C and evaluated by whether or not it was deformed. (○ indicates that it was not deformed.) (D) Weather resistance Spherical particles were left for 2 months in a place exposed to the sun outdoors.
It was evaluated by whether or not the color changed. (○ indicates that no discoloration occurred.) (E) Chemical resistance It was evaluated by immersing it in an equal weight mixture of phenol and ethane tetrachloride at 30 ° C for 1 hour and swelling. (○ indicates that it did not swell.)

Production Example 1 In an esterification reaction can, 50.0 kg of bis (β-hydroxyethyl) terephthalate and its oligomer, 12 kg of neopentyl glycol, tetrabutyl titanate (catalyst) 26
g, and after carrying out an esterification reaction at 250 ° C. under 3.6 kg / cm ² of nitrogen gas pressure suppression for 2 hours, transfer to a polymerization reaction vessel and
The temperature was raised to 0 ° C. and polycondensation reaction was carried out at 0.4 torr for 4 hours to obtain a polyester resin.

Production Example 2 In an esterification reactor, 35 kg of bis (β-hydroxyethyl) terephthalate and its oligomer were mixed with dodecanedioic acid.
17.3kg, neopentyl glycol 12kg, tetrabutyl titanate (catalyst) 26g, 250 ℃, under nitrogen gas suppression
After performing an esterification reaction at 3.6 kg / cm ² for 2 hours, the mixture was transferred to a polymerization reaction kettle, heated to 280 ° C., and subjected to polycondensation reaction at 0.4 torr for 4 hours to obtain a polyester resin. (Aromatic dicarboxylic acid component 70 mol%)

Example 1 30 kg of the polyester resin obtained in Production Example 1 was charged into a polymerization reaction kettle and melted at 280 ° C. and 3.6 kg / cm ² under nitrogen gas pressure suppression, and pentaerythritol was used as a cross-linking agent under stirring to dicarboxylic acid. A polyester resin composition was obtained by adding 5 mol% to the acid component and reacting for 2 hours. The obtained polyester resin composition was discharged from a polymerization reaction kettle onto a polytetrafluoroethylene sheet in a sheet form, cooled, and then pulverized. 5 kg of this pulverized product and 30 kg of dioxane were put into a 50-liter vat and stirred at room temperature to dissolve the thermoplastic resin portion. The obtained solution was filtered using filter paper (TOYO FILTER PAPER 2 manufactured by Advantech Toyo Co., Ltd.). As a result, 50 g of thermosetting polyester spherical particles having an average particle diameter of 230 μm and a ratio of major axis to minor axis of 1.1 were obtained. The results of evaluating the characteristics of the spherical particles are shown in Table 1.

Examples 2 to 6 The polyester resin and the cross-linking agent shown in Table 1 were used.
The reaction was carried out under the conditions shown in 1 to obtain thermosetting polyester spherical particles in the same manner as in Example 1. The results are shown in Table 1.

Comparative Examples 1 to 5 The polyester resin and the cross-linking agent shown in Table 1 were used.
The reaction was performed under the conditions shown in, but no spherical particles were obtained. (In Comparative Example 1, the amount of the cross-linking agent was small and almost no spherical particles were obtained, in Comparative Example 2, the reaction product gelled, in Comparative Example 3, the cross-linking agent melted too fast, and in Comparative Example 4,
Since the reaction temperature was low and the reaction did not occur, in Comparative Example 5, the polyester resin A was thermally decomposed. )

[0029]

[Table 1]

[0030]

According to the present invention, spherical polyester particles having a high sphericity and excellent chemical resistance, heat resistance and light resistance are provided. The thermosetting polyester spherical particles of the present invention are suitably used as an anti-blocking agent, a matting agent, an organic filler, a thickness gap adjusting agent, an electronic material and the like which require these properties.

Claims (3)

[Claims] 1. An average particle comprising a polyester obtained by crosslinking a polyester mainly composed of a dicarboxylic acid component and an diol component, in which an aromatic dicarboxylic acid accounts for 60 mol% or more, by crosslinking with a trifunctional or more functional ester-forming compound and thermally curing the polyester. Diameter
Thermosetting polyester spherical particles having a diameter of 0.1 to 500 μm and a ratio of major axis to minor axis of 1.0 to 1.2. 2. A trifunctional or higher functional ester-forming compound,
The thermosetting polyester spherical particles according to claim 1, which are one or more compounds selected from trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride and pentaerythritol. 3. A polyester resin A mainly composed of a dicarboxylic acid component and an diol component in which an aromatic dicarboxylic acid accounts for 60 mol% or more is heated under an inert gas atmosphere at a temperature T (° C.) satisfying the formula (1). A dicarboxylic acid component which has a melting point t (° C.) satisfying the formula (2) and is a trifunctional or higher functional ester-forming compound which is soluble in the polyester resin A in powder form and constitutes the polyester resin A. Against
A method for producing thermosetting polyester spherical particles, which comprises adding 0.5 to 10 mol% and reacting under stirring to obtain a resin composition containing thermosetting spherical polyester, and separating the thermosetting spherical polyester. . 150 ≦ T ≦ 300 (1) T-100 ≦ t (2)