JPH02119011A - Resin composition for extrusion sheet and electric insulation board - Google Patents

Abstract

PURPOSE:To obtain an insulation board by using a composition made up by mixing an inorganic compound, phenylene bisoxazolin and fibre reinforcement in polyester having polyethylene terephthalate or ethylene terephthalate cyclic unit. CONSTITUTION:Polyethylene terephthalate is a melt polymer made up of terephthalic acid or ester of terephthalic acid and ethylene glycol, or a solid phase polymer thereof. Polyester having ethylene terephthalate cyclic unit is a copolymer of ethylene terephthalate cyclic unit of 80mol% or more and another cyclic unit. Silica with an average grain size of less than 50mu, etc., at 5-30 parts by weight, 2,2'-(1,2-phenylene)-bis(2-oxazolin), etc., at 0.1-10 parts by weight and reinforcement of glass fibre with length of approx. 0.1-10mm at 5-10 parts by weight are mixed in the components of the above copolymer at 100 parts by weight, and a sheet using this resin composition is heat-treated and the degree of crystallinity thereof is kept at 10%. This constitution makes it possible to obtain a thermoplastic insulation board with good dimensional stability, punchability at an ordinary temperature and a high modulus of elasticity.

Description

[Detailed description of the invention] (Industrial application field) The present invention uses polyester resin as a matrix.

A resin composition capable of producing an extrusion molded sheet that is hard and has a smooth surface and has low anisotropy in mechanical properties such as bending strength, and electrical insulation properties.1 Dimensional stability.

This invention relates to an electrical insulation board with excellent heat resistance and punching workability.

(Conventional technology) Polyethylene terephthalate has excellent mechanical properties, electrical properties, heat resistance, chemical resistance, etc., and is used as a fiber.

It is used in many industrial products as injection molded products, films, and sheets. In addition, when producing a sheet with a smooth surface and high elastic modulus, the general method is to melt and extrude a composite chip of polyethylene terephthalate resin filled with inorganic compounds, short glass fibers, etc. through a T-die to form a sheet. It is used.

However, in the case of this method, the surface is certainly smooth and the longitudinal direction (
Although it is possible to produce a sheet with a high elastic modulus in the opening direction (hereinafter referred to as the opening direction), polyethylene terephthalate molecules and short glass fibers are oriented during melt extrusion through a T-die, resulting in bending strength in the width direction (hereinafter referred to as the TO force direction). 1. Only sheets with an extremely low bending modulus can be produced compared to that in the MO force direction. When such sheets with strong anisotropy are used industrially, the field of use is greatly narrowed due to design constraints.

In addition, as a method for alleviating this anisotropy, some methods have been devised in which randomly oriented short glass fiber mats, long glass fiber swirl mats, glass fiber fabrics, etc. are laminated immediately after melt extrusion from a T-die. However, this method requires large-scale equipment, high equipment costs, poor productivity, and high manufacturing costs.

In addition, as electrical insulation boards, laminates are widely used, which are made by laminating thermosetting resin panels such as phenolic resin and epoxy resin, which have excellent electrical insulation properties, onto a base material such as paper or glass fabric. . However, this method requires large-scale equipment, high equipment costs, poor productivity, and high manufacturing costs.

This thermosetting resin has excellent chemical resistance and water resistance, but when paper is used as the base material for the laminate, not only the chemical resistance of the resin itself is poor, but also the dimensional change due to moisture absorption is large. This results in a considerably limited range of industrial use.

Furthermore, in the punching process, cracking and delamination often occur, so it is necessary to carry out the process under heating at 40° C. or higher, although this increases the cost.

On the other hand, in the case of laminated plates using glass fabric as a base material, one-dimensional stability and chemical resistance are improved, but there are economic constraints due to the high cost of the glass fabric, and problems in punching processing remain. It remains as it is.

(Problems to be Solved by the Invention) As mentioned above, when trying to obtain a sheet with a hard and smooth surface using a polyester resin as a matrix, a sheet formed by conventional general melt extrusion molding has an MO force direction and a TD force direction machine. The anisotropy of the physical properties is too strong.

Furthermore, if an attempt was made to improve this device, a large-scale device would be required, which would be economically disadvantageous.

Furthermore, as an electrical insulating board, a laminate made of a thermosetting resin and a glass cloth, as mentioned above, is expensive to manufacture and has dimensional stability and chemical resistance.

No electrical insulating board has been manufactured that can be used in a wide range of industries because it does not satisfy the requirements such as room-temperature punching workability.

Under these circumstances, one object of the present invention is to suppress the orientation of molecules and fibrous reinforcing materials during melt extrusion from a T-die, even when manufactured using a conventional general melt extrusion sheet forming method,
By providing a resin composition that yields a sheet with less anisotropy in mechanical properties in the TO force direction, and by using a crystallized sheet-like molded product made from the resin composition, it is possible to use it as an inexpensive electrical insulating board. The purpose of this invention is to provide a thermoplastic electrical insulating board that satisfies all of the dimensional stability, chemical resistance, room-temperature punching workability, etc. required for use.

(Means for Solving the Problems) The present inventors have conducted extensive research for the above purpose, and as a result, have arrived at the present invention.

That is, 1 the present invention is based on 100 parts by weight of polyethylene terephthalate or a polyester having at least 80 mol% or more of ethylene terephthalate repeating units, (a) 5 to 30 parts by weight of an inorganic compound with an average particle size of 50 μm or less, and (b) phenylene. Bisoxaprine 0.1-1
0 parts by weight, ()\) A resin composition for an extrusion-molded sheet comprising 5 to 50 parts by weight of a fibrous reinforcing material, and an electrical insulation obtained by heat-treating a sheet using the resin composition to a degree of crystallinity of 10% or more. It's about the board.

Polyester resin has good electrical insulation properties.

Although it has been well known that extruded sheets have excellent dimensional stability, water resistance, and chemical resistance, their mechanical properties are insufficient when used as electrical insulation boards. ) component, i.e., fibrous reinforcement such as glass fiber is required.

Because the molecules and fibrous reinforcing material are oriented during melt extrusion for sheet formation, it exhibits high anisotropy in mechanical properties. It has been found that it is necessary to add component (2), that is, phenylenebisoxapurine, as an anisotropy relaxant.

In other words, the molecules of phenylene bisoxaprine and polyethylene terephthalate partially undergo a crosslinking reaction during melt-kneading, partially forming a two-dimensional molecular structure, and the orientation of the molecules and fibrous reinforcing material during melt extrusion from a T-die. It acts as a hindrance. Component (a), that is, an inorganic compound with an average particle size of 50 μm or less, is highly effective in imparting smoothness to the sheet surface, mitigating anisotropy in mechanical properties, and acting as a crystallization promoter. For an electrical insulation board that can be widely used in all industrial fields, it is necessary to further improve the elastic modulus and heat resistance, but it is necessary to heat-treat the sheet using the resin composition to a crystallinity of 10% or more. be.

Note that the resin composition in the present invention further contains a heat stabilizer, an oxidation stabilizer, a light stabilizer, and a lubricant, if necessary.

Additives such as pigments, flame retardants, and desensitizers may be added.

(Function) A sheet obtained by extrusion molding from a resin composition for an extrusion molded sheet obtained by blending components (a), (b), and (c) with a polyester resin has a smooth surface, a high modulus of elasticity, and It is a composition that exhibits low anisotropy in mechanical properties in the opening direction TD direction and is useful as a material for extrusion molded sheets, when a sheet made of the composition is crystallized by 10% or more.

Furthermore, it has a high modulus of elasticity, and even when punched at room temperature, there is no cracking or peeling of N, and it is recognized that the workability is significantly improved compared to the conventionally used laminate made of thermosetting resin.

The degree of crystallinity described here is determined by infrared total reflection absorption spectroscopy. The method will be described below.

Ten types of crystallinity measurement standard samples were prepared by heat-treating polyester films with a thickness of 100 μm at different temperatures and times, and FT4R-ATR spectra were measured.

Crystallized band 1341cn+-' and normalized band 140
Find the absorbance ratio (P) at 9 cm-'. Regarding the dependence of these two types of bands on the crystallinity of polyester resin,
Jo-urnal Polymer 5science
, Polymer Letter Edition.

νOL, 12. P, 13 (1974). When this absorbance ratio (P) is plotted against the crystallinity (Xc) determined by the density method for 10 types of samples, the linear relationship shown below is obtained.

(Relational formula: Xc=37.8IP-7,44C%) The relationship between the crystallinity (Xc) and density (ρX) of polyester resin is well known.

(Relational formula ■) ρX −ρa Xc−xtoo (%) ρC−ρa (However, ρC is the density of the crystallized polyester resin and is 1.
455 g/cIIY, ρa is the density of the amorphous polyester resin, which is 1.335 g/cT1. ) is obtained using the relational expression. Therefore, the crystallinity of the unknown sample is
The degree of crystallinity can be determined from the absorbance ratio of the 1341 cm-' band and the 1409 cm-' band using the above relational expression (2).

If the crystallinity measured by this method does not reach 10%,
Since the elastic modulus of the sheet is insufficient and deformation occurs during punching and thermal deformation during spot soldering, the degree of crystallinity must be 10% or more, preferably 18% or more. The shortest method for crystallizing a sheet is to extrude it from a T-die and heat press it from both sides at a temperature above the glass transition point and below the melting point. It is possible to do this, but it is preferable to do so during open hot air (
Far) infrared heater irradiation, heat roll press, etc. may be employed.

The polyethylene terephthalate used in the present invention is obtained from terephthalic acid or an ester of terephthalic acid and ethylene glycol by a conventional melt polymerization method, or it is obtained by subjecting it to solid phase polymerization. And polyester having at least 80 mol% or more of ethylene terephthalate repeating units means 80 mol%
It means a copolymer consisting of the above ethylene terephthalate repeating unit and other repeating units, that is, other copolymerization components, and various acid components and glycol components can be used as the above other copolymerization components. .

For example, acid components include isophthalic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenylsulfone dicarboxylic acid, p-(2-hydroxyethoxy)benzoic acid, 5-
Sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecane-1,12-dicarboxylic acid, tetradecane-1,14-dicarboxylic acid, hexadecane-1,16-dicarboxylic acid, octadecane-1,18-dicarboxylic acid
Dicarboxylic acid, 6-ethyl-hexadecane-1,16-
Examples include dicarboxylic acids.

In addition, the glycol components include propylene glycol,
Examples include polyalkylene gelols such as diethylene glycol, butylene glycol, pentyl glycol, neopentyl glycol, hexamethylene glycol, polyethylene glycol, and polytetramethylene glycol.

The electrically insulating inorganic compound used as component (a) of the present invention may be used as a smoothing agent for the sheet surface depending on its particle size and shape.
Reinforcing material 9 has different effects as an anisotropic relaxant of mechanical properties and a crystal nucleating agent. Generally, inorganic compounds with an average particle size of 50 microns or less are useful, since the effect decreases when the average particle size exceeds about 50 microns.

Specific examples include silica, calcium carbonate, synthetic silicic acid and silicates, zinc white, hallosite flekaolin, basic magnesium carbonate, and mica.

Examples include talc-1 quartz powder, wollastonite dolomite powder, titanium oxide, barium sulfate, calcium sulfate alumina, and one or more of these inorganic compounds can be used. Among them, talc, mica, and wollastonite are particularly effective in the present invention. Phenylenebisoxapurine used as component (b) is a compound represented by the following general formula.

R1 to R8 in the general formula are each a hydrogen atom or a monovalent hydrocarbon group, and a hydrogen atom is particularly preferred.

Specific examples of the compound include 2.2'' (1,2-phenylene)-bis(2-oxazoline), 2.2゜(1
,3-phenylene)-bis(2-oxazoline).

2.2°-(1,4-phenylene)-bis(2-oxazoline), 2.2”-(1,2-phenylene)-bis(
4-methyl-2-oxazoline), 2,2°-(13-
phenylene)-bis(4-methyl-2-oxazoline)
2.2'-(L4-phenylene)-bis(4-methyl-2-oxazoline) and the like. The oxazoline group in the compound undergoes a crosslinking reaction with polyester molecules during melt-kneading to form a dimensional molecular structure, and as a result, anisotropy in mechanical properties is alleviated.

Specific examples of the fibrous reinforcing material used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and titanate fibers. Glass fiber is usually used. In addition, there are no particular restrictions on the diameter and length of the various fibers, but if the fiber length is too long, it will be difficult to mix and disperse uniformly with polyester and other compounding agents; If it is too large, the effect as a reinforcing material will be insufficient.3 Usually, fibers with a fiber length of 0.1 to 10 mm are used, and especially when the fibrous reinforcing material is glass fiber, the fiber length is 0.1 mm. ~7 mm is preferable, and more preferably 0
．． 3 to 4 mm is desirable.

Further, the fibrous reinforcing material may be treated with various compounds as necessary in order to improve the interfacial adhesion with polyester and enhance the reinforcing effect. When using glass fibers as fibrous reinforcement, various surface treatment agents are used, such as vinyltriethoxysilane, γ-methacryloxypropylmethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxy silane,
Silane treatment agents such as γglycidoxypropyltrimethoxysilane, T-aminopropyltriethoxysilane, T-chloropropylmethoxysilane, and T-mercaptopropyltrimethoxysilane.

Those treated with a chromium-based treatment agent such as methacrylate chromic chloride are used.

Regarding the blending ratio of each component in the resin composition of the present invention,
Ingredient (a), that is, an inorganic compound with an average particle size of 50μ or less, is an additive with multifunctional purposes such as a surface smoothing agent for the sheet, a reinforcing material, an anisotropy relaxing agent for mechanical properties, and a crystal nucleating agent. . If the amount is less than 5 parts by weight based on 100 parts by weight of the polyester component, the effect as a surface smoothing agent for the sheet 9 Anisotropy relaxant for mechanical properties 9 Reinforcing material will be insufficient, and conversely, more than 30 parts by weight will be incorporated. As a result, the mechanical properties deteriorate significantly. Therefore, the amount of component (a) to be blended is 5 to 30 parts by weight per 100 parts by weight of the polyester component.

Preferably it is 10 to 24 parts by weight. Regarding the amount of component (b), i.e., phenylenebisoxazoline, if it is less than 0.1 parts by weight, the formation of a two-dimensional molecular structure due to cross-linking will be insufficient; on the other hand, if it is more than 10 parts by weight, It is also undesirable because it promotes gelation. Therefore, the blending amount of component (b) is 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight. (c) Ingredients,
Regarding the blending amount of the fibrous reinforcing material, if it is less than 5 parts by weight, its effect as a reinforcing material will be insufficient, and if it exceeds 50 parts by weight, the smoothness of the sheet surface will be significantly impaired. Therefore, the blending amount of the fibrous reinforcing material is 5 to 50 parts by weight, preferably 10 to 40 parts by weight.

(Example) Examples 1 to 3 Polyethylene terephthalate 100 with intrinsic viscosity 0.95
Three types of compositions according to the present invention (Examples 1 to 3) as shown in Table 1 are blended into the parts by weight and melted and kneaded using a twin-screw press ratio machine to create pellets, which are then mixed using a T-die. When molded into a 1 mm thick sheet using an extrusion sheet molding apparatus, a sheet with a smooth surface and good appearance as shown in Table 2 could be obtained. Further, when the bending strength and bending elastic modulus were measured, the physical properties showed low anisotropy, giving good results.

Comparative Examples 1 to 6 Six types of comparative compositions (Comparative Examples 1 to 6) as shown in Table 1 were added to 100 parts of the same polyethylene terephthalate as in Examples 1 to 3 above.

Melt and knead with a twin-screw presser to create pellets, which are then
When the extrusion work was performed using an extrusion sheet forming device using a die, as shown in Table 2, 2°2'-(1,3-
In Comparative Example 4, which contained a large amount of 13 parts by weight of (phenylene)-bis(2-oxazoline), a gelled substance was generated, making it impossible to form a sheet. In addition, Comparative Example 2, which contains 36 parts by weight of inorganic compounds such as talc and mica, has a slightly rough surface, and Comparative Example 6, which contains 55 parts by weight of glass fibers, has a rough surface. It was something without.

Furthermore, when we measured the bending strength 2 flexural modulus of Comparative Examples 1, 2, and 3.5, we found that Comparative Example 1, which contains only 4 parts by weight of inorganic compounds, and Comparative Example 3, which does not contain PBO, exhibit anisotropy. Comparative Example 2 containing 36 parts by weight of inorganic compounds and Comparative Example 5 containing as little as 3 parts by weight of glass fibers had low bending strength, and both had low commercial value.

Table 1 Comparative Examples 7 to 11 The crystallinity of the sheet prepared in Example 1 and the sheet prepared in Example 2 was O (Comparative Examples and 9). In addition, the sheets of Examples 1 and 3 were crystallized by applying heat for 1 minute at a temperature of 105 DEG C. and a pressure of 0.5/cIII in the same manner as in Examples 4 to 7.

The crystallinity was 8% in all cases (Comparative Examples 8 and 10).
). Regarding these four types of sheets, as in Examples 4 to 7, we conducted measurements regarding 2 necessary materials for electrical insulating boards, and as shown in Table 3, their bending strength was low, and their use was limited to 7. It turned out that it was not possible.

Furthermore, when similar measurements were carried out on Giophenol laminates, which have been conventionally used as electrical insulating boards, the results showed that the bending strength was lower than other comparative examples, but the water resistance was poor and the board was punched.

The appropriate temperature for the process was also as high as 145°C (Comparative Example 11).

Examples 4 to 7 The sheets prepared in Example 1 were crystallized by applying heat for 1 minute under a pressure of 0.5 Kg/ctM using a heat press machine at a temperature of 170°C. As shown in (Example 4), the crystallinity was 30%. Similarly, for the sheet prepared in Example 1, the temperature was 120″C1.
When crystallization was performed by applying heat for 1 minute at a pressure of 0.5 and g/c+fl, the degree of crystallinity was 14% (Example 5)
).

Furthermore, regarding the sheets created in Examples 2 and 3,
When crystallization was performed by applying heat for 1 minute at a temperature of 170"C and a pressure of 0.5 Kg/cnl, the crystallinity was 32% and 31%, respectively (Examples 6 and 7). About crystallized sheets.

When we measured the typical properties necessary for an electrical insulation board, such as bending strength, surface resistivity, water absorption, water resistance, and suitable punching temperature, we found good results in all of them, as shown in Table 3. It has been found that it can be used in a wide range of applications.

(Effects of the Invention) The extruded sheet made of the resin composition of the present invention has low anisotropy in mechanical properties, and the electrical insulating board obtained by crystallizing such a molded sheet.

Although it can be manufactured with high efficiency using small-scale equipment, it has one-dimensional stability and chemical resistance.

It has excellent room-temperature punching workability, high elastic modulus, and high fij impact strength. Therefore, it is a new thermoplastic electrical insulation board that can be used in a wide range of industries and can be used even under harsh conditions.

Patent applicant: Unitika Co., Ltd.

Claims (2)

[Claims] (1) For 100 parts by weight of polyethylene terephthalate or polyester having at least 80 mol% or more of ethylene terephthalate repeating units, (a)
5 to 30 parts by weight of an inorganic compound with an average particle size of 50 μ or less, 0.1 to 10 parts by weight of (b) phenylenebisoxazoline,
(c) A resin composition for extrusion-molded sheets containing 5 to 50 parts by weight of a fibrous reinforcing material. (2) An electrical insulating board obtained by heat-treating a sheet using the extrusion molded sheet resin composition according to claim (1) to a degree of crystallinity of 10% or more.