JPH09143346A - Flame-retardant polyester block copolymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester compsn. for electric wire which is soft and has sufficient flame-retardancy by compounding a polyester block copolymer comprising specific hard and soft segments with ammonium sulfate and a melamine compd. SOLUTION: This flame-retardant polyester compsn. is prepd. by compounding 100 pts.wt. polyester block copolymer comprising polybutylene terephthalate blocks formed from a dicarboxylic acid component contg. at least 60mol% terephthalic acid and a glycol component contg. at least 60mol% tetramethylene glycol as the soft segements and polyether blocks or polyester blocks soft at room temp. as the soft segments with 1-100 pts.wt. ammonium sulfate and 1-100 pts.wt. melamine compd. Pref. the copolymer has a wt. ratio of soft to hard segments of (70:30)-(30:70) and an intrinsic viscosity of 0.8-1.5. Pref., ammonium sulfate having a particle size of 100 mesh or finer and prevented from blocking by a surfactant, etc., is used. Examples of the melamine compd. are melamine and melamine cyanurate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a specific flame-retardant polyester block copolymer composition. More specifically, a non-halogen compound prepared by blending ammonium sulfate and a melamine compound into a specific polyester block copolymer,
Non-phosphorus flame-retardant polyester block copolymer composition.

[0002]

2. Description of the Related Art Polyester block copolymers of a hard segment containing polybutylene terephthalate as a main component and a soft segment consisting of polyether and / or polyester flexible at room temperature have excellent chemical resistance and heat resistance. Known as flexible block polyester.

However, this polyester block copolymer is not sufficiently flame-retardant, which is a problem when it is used in, for example, electrical applications, and its applications are often limited.

When halogen-based flame retardants and antimony oxide, which are generally used as flame retardants for polyester, are used, flame retardancy is improved but elongation at break is reduced, and harmful dioxin is generated by waste. It is not preferable because it may cause pollution problems.

Further, a flame-retardant composition using a phosphorus compound is also known, but in this case, too, the toxicity of the phosphorus compound generated during combustion is a problem.

Therefore, the inventors of the present invention have conducted extensive studies to obtain a flame-retardant composition having elongation, and as a result, it has been found that ammonium sulfate can be used as a flame retardant, and that if this ammonium sulfate is used as a flame retardant, polyester It was found that a flame-retardant composition can be obtained while maintaining the breaking elongation of the block copolymer, and that this ammonium sulfate does not generate diioxin, etc., and that the dropping during combustion can be suppressed, and it was previously proposed.

However, in the technique of using only ammonium sulfate as a flame retardant, when treated in hot water, for example, ammonium sulfate starts to melt and adheres to the surface to reduce electric resistance, which is disadvantageous in some applications.
It was discovered by the subsequent examination.

[0008]

An object of the present invention is to solve the above problems and obtain a polyester block copolymer composition having excellent flame retardancy without using a halogen or phosphorus compound.

[0009]

As a result of repeated studies to solve the above-mentioned problems, the present inventors have found that by using ammonium sulfate and a melamine compound as flame retardants at the same time without using a halogen or phosphorus compound. Further, it was found that a polyester block copolymer composition having excellent flame retardancy can be obtained without further containing a large amount of ammonium sulfate, and that this composition has little elution of ammonium sulfate, and thus the present invention is completed. Arrived

That is, according to the present invention, polybutylene terephthalate in which 60 mol% or more of dicarboxylic acid component and glycol component are terephthalic acid and tetramethylene glycol is used as a hard segment, and a polyether and / or a flexible polyester at room temperature (25 ° C.) is used. A flame-retardant polyester block copolymer composition comprising 100 parts by weight of a polyester block copolymer (A) having 1 to 100 parts by weight, 1 to 100 parts by weight of ammonium sulfate (B), and 1 to 100 parts by weight of a melamine compound (C). is there.

The present invention will be described in detail.

In the polyester block copolymer (A) used in the present invention, polybutylene terephthalate in which 60 mol% or more of the dicarboxylic acid component and the glycol component are terephthalic acid and tetramethylene glycol is used as a hard segment. Aromatic dicarboxylic acid containing benzene ring or naphthalene ring other than terephthalic acid as dicarboxylic acid component, aliphatic dicarboxylic acid having 4 to 12 carbon atoms, and aliphatic diol having 2 to 12 carbon atoms other than tetramethylene glycol as diol component, cyclohexane A diol such as an alicyclic diol such as dimethanol may be copolymerized, and the copolymerization ratio is less than 40 mol%, preferably less than 30 mol% based on the total dicarboxylic acids. The smaller the copolymerization ratio, the higher the crystallinity and the higher the melting point. On the one hand, there is also the advantage of being softened by copolymerization.

Although this copolymerization ratio is difficult to specify in the block copolymer of the present invention, it is preferable to apply the copolymerization ratio such that the melting point of the crystal is 150 ° C. or higher, more preferably 160 ° C. or higher. .

When a polyether is used as the soft segment, a condensed form of polyether such as ethylene glycol, propylene glycol or tetramethylene glycol is generally used as the polyether. Polyethers derived from aromatic diols such as bisphenols may be included. Particularly, polytetramethylene glycol is preferably used. The polyether has a molecular weight of 400 to 5000, more preferably 6
Those of 00 to 2000 are preferably used.

In the polyester block copolymer having polyether as the soft segment, the weight ratio of the hard segment to the soft segment is 20 to 80:80.
20 and preferably 30 to 70 to 70 to 30. Regarding the weight ratio of the hard segment and the soft segment, when the hard segment is more than this range, there is little advantage of using a polyester block copolymer, and when the number of the soft segment is many, the crystallinity becomes low and molding becomes difficult.

When polyester is used as the soft segment, the polyester has 4 to 10 carbon atoms.
Polyester composed of 12 aliphatic dicarboxylic acid and aliphatic diol having 2 to 12 carbon atoms, polyester of aliphatic oxycarboxylic acid having 6 to 12 carbon atoms, or 8 to 14 carbon atoms
Which is a polyester composed of the aromatic dicarboxylic acid and a diol having 5 to 12 carbon atoms and is flexible at room temperature (25 ° C.).

Regarding the polyester used as the soft segment, "flexible at room temperature (25 ° C)" means that the glass transition point is 25 ° C or lower, and the melting point is less than 100 ° C or amorphous polyester. It is preferable.

For this purpose, a copolymer is preferably used,
Further, the above mutual copolymers can of course be used.

Among the aromatic dicarboxylic acids, phthalic acid, isophthalic acid, terephthalic acid, and naphthylenedicarboxylic acid are preferable as the dicarboxylic acid as a constituent component of the polyester. Particularly, non-linear dicarboxylic acids such as phthalic acid and isophthalic acid are preferable. Preferably, among the aliphatic dicarboxylic acids, succinic acid, adipic acid, azelaic acid, sebacic acid,
Decanedicarboxylic acid is preferable, and cyclohexanedicarboxylic acid is preferably used among alicyclic dicarboxylic acids.

Examples of the diol as a constituent component of the polyester include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, 3-methyl-1,5-pentanediol and 2-methyl-1,8-octanediol. can give. When used in combination with an aromatic dicarboxylic acid, a diol having 5 or more carbon atoms is particularly preferable. Further, a diol having an ether bond such as diethylene glycol or triethylene glycol is also preferably used.

An oxycarboxylic acid can also be used as a copolymerization component. Oxycaproic acid is common.

In particular, a polyester having a polyester unit consisting of an aromatic dicarboxylic acid and a diol having 5 or more carbon atoms in an amount of 60 mol% or more is excellent in hydrolysis resistance and flame retardancy can be obtained even if the amount of ammonium sulfate is small. Therefore, it is preferable.

In the polyester block copolymer having polyester as the soft segment, the amount ratio of the hard segment and the soft segment is not particularly limited.

The segment lengths of the soft segment and the hard segment of the polyester block copolymer used in the present invention are expressed by molecular weight and are about 500 to 70.
00 is preferable, and 800 to 5000 is more preferable. Although it is difficult to directly measure this segment length, for example, the composition of the polyester constituting the soft segment and the hard segment, the melting point of the polyester composed of the components constituting the hard segment, and the obtained polyester block copolymer It can be estimated from the melting point of the coalescence using the Flory equation.

Any known method may be used for producing the polyester block copolymer (A). For example, those having a soft segment of polyether include those having an ester-forming terminal such as a hydroxy group in a usual melt polymerization. ,
It can be obtained by adding and polymerizing a polyether compound having a terminal such as carboxy in the same manner as a usual monomer.
In addition, those having a polyester as a soft segment are produced by respectively producing polyesters composed of components constituting a hard segment and a soft segment, and melt-mixed to have a melting point of 2 to more than the polyester constituting the hard segment.
It can be obtained by using a method of lowering the temperature by 40 ° C., a method of adding and reacting a cyclic ester such as caprolactone in polyester constituting the hard segment, and the like.

The polyester block copolymer (A) is
It has an intrinsic viscosity of 0.6 or more, preferably 0.8 to 1.5, as measured in 35 ° C. orthochlorophenol.
This is because when the intrinsic viscosity is lower than this, the strength is low, the viscosity is low, and it is difficult to use, and it is meaningless to apply the present invention.

In the present invention, ammonium sulfate (B) and melamine compound (C) are added to the above polyester block copolymer (A) to prepare a flame retardant composition.

The ammonium sulphate (B) used as the flame retardant is not particularly limited, but naturally it is not preferable that it contains impurities that decompose the polyester block copolymer as impurities. For example, when sulfuric acid is contained as an impurity, it is colored or decomposed, so the amount of the impurity is preferably 0.1 parts by weight or less.

The particle size of ammonium sulfate (B) may be 10 to 50 mesh, which is usually commercially available, as it is, but if extruded, the surface condition may deteriorate. In many cases, it is preferable to use. In this case, 100-500 mesh is preferable.

Since such ammonium sulfate (B) may adhere to each other even when finely pulverized,
It is also a preferable method to prevent sticking by treating the surface with a surfactant or mixing particles smaller than the particle size of ammonium sulfate. As a surfactant,
Sulfonic acid compounds are preferable, and examples thereof include alkylsulfonic acids having 10 to 30 carbon atoms or sodium salts of alkylbenzenesulfonic acids. When a surfactant is used, its amount is 0.1-10 with respect to ammonium sulfate.
% By weight.

Any particles can be used for preventing sticking as long as they can be used stably, and examples thereof include inorganic fine particles such as silica fine particles. When these particles are used, the amount used is 1 to 10 with respect to ammonium sulfate.
0% by weight.

The amount of ammonium sulfate (B) as the flame retardant is 1 to 100 parts by weight, preferably 5 to 70 parts by weight, based on 100 parts by weight of the polyester block copolymer. If it is less than this range, the flame retardancy is not sufficient, and if it is more than this, the tensile elongation and impact strength are lowered.

As the melamine compound (C) which is the other component used as the flame retardant in the present invention, melamine and / or melamine cyanurate is preferred. The amount used is 1 to 100 parts by weight, preferably 5 to 70 parts by weight. This melamine compound should also be fine, 100
It is preferably about 500 mesh.

In order to impart flame retardancy, it is particularly preferable that the total amount of ammonium sulfate and melamine compound is about 20 to 50 parts by weight per 100 parts by weight of the polyester block copolymer.

The composition of the present invention can be obtained by melt-mixing a polyester block copolymer with ammonium sulfate and a melamine compound. For example, it is manufactured by extrusion using an extruder. This extrusion temperature is usually above the melting point, for example 160 ° C to 260 ° C, preferably 18 ° C.
It is 0-240 degreeC. This is because the decomposition of ammonium sulfate and the decomposition of polyester due to this decomposition product occur at a temperature higher than this, and it is often impossible to melt at a lower temperature.

The composition of the present invention thus obtained contains a stabilizer, a reinforcing material, a pigment, a dye, a nucleating agent, in addition to the polyester block copolymer, ammonium sulfate and melamine compound.
It may contain a lubricant and other additives, and may be a mixture with other polymers. Examples of polymers that can be added as a mixture include polyesters such as polybutylene terephthalate, ethylene, and (meth)
Examples thereof include copolymers of acrylic acid ester, vinyl acetate, styrene and the like. The amount of these additives and polymers is 0.01 to 50 parts by weight based on 100 parts by weight of the composition of the present invention.

[0037]

The present invention will be described in detail with reference to examples. In the examples, “parts” means “parts by weight”.

Reference Example 1 Dimethyl isophthalate 175
Part, 23 parts of dimethyl sebacate and 140 parts of hexamethylene glycol are subjected to a transesterification reaction with a dibutyltin diacetate catalyst, and then polycondensed under reduced pressure to give an intrinsic viscosity of 1.06.
By the DSC method, an amorphous polyester showing no endothermic peak due to melting of crystals was obtained. Separately, polybutylene terephthalate chips having an intrinsic viscosity of 0.98 obtained by polycondensation were dried and added to 107 parts of the polyester and reacted at 240 ° C. for 45 minutes, and then phenylphosphonic acid was added. The reaction was stopped by adding 0.1 part. This polyester block copolymer was taken out and made into chips to be used as a raw material. The melting point of this chip is 190 ° C,
The intrinsic viscosity was 1.03.

[Reference Example 2] Dimethyl isophthalate 125
, 54 parts of dimethyl sebacate and 140 parts of hexamethylene glycol were subjected to a transesterification reaction with a dibutyltin diacetate catalyst, followed by polycondensation under reduced pressure to obtain a polyester having an intrinsic viscosity of 1.06.

Reference Example 3 Dimethyl terephthalate 44
Parts, tetramethylene glycol 40 parts, molecular weight 1500
Polytetramethylene glycol (50 parts) was polymerized at 240 ° C. by a normal melt polycondensation reaction using a titanium tetrabutoxide catalyst to obtain a polyester block copolymer having an intrinsic viscosity of 1.24.

Example 1 To 100 parts of the polyester block copolymer of Reference Example 1, 15 parts of ammonium sulfate and 15 parts of melamine cyanurate passing through a 200-mesh wire net were charged from the hopper of the extruder and extruded at 220 ° C. .
This composition was subjected to extrusion coating at 220 ° C. at 0.5
A stranded mm copper wire was coated to a thickness of 0.3 mm to obtain a coated electric wire. This coated electric wire was tested by a method according to the ISO 6722 45 ° diagonal test, but the fire of the coated electric wire was extinguished at the same time when the fire was removed. At this time, the amount of smoke was obviously smaller than that in the case of using Fireguard (manufactured by Teijin Chemicals Ltd.), which is a polycarbonate of brominated bisphenol-A, and flame retardant with antimony oxide (Comparative Example 3).

The coated electric wires obtained by extrusion in the examples were smooth.

As a result of setting the molding temperature to 250 ° C., the color of the molded product turned brown, but the flame retardancy did not change.

[0044]

[Table 1]

[Examples 2 to 4] Perprene S1001 (manufactured by Toyobo Co., Ltd .: abbreviated as S1001 in the table), which is a polyester block copolymer using polycaprolactone, was used. A composition in which the amount of ammonium sulfate and the amount of melamine compound were as shown in Table 1 was obtained, and the flame retardancy and physical properties were measured. Table 1 shows the results.

Examples 5 to 7 and Comparative Examples 1 to 3 Polytetramethylene terephthalate, ammonium sulfate and a melamine compound were added to the polyester block copolymer of Reference Example 1 to give the compositions shown in Table 2. The composition was obtained, and the same coated electric wire as in Example 1 was tested for flammability. Table 2 shows the results.

[0047]

[Table 2]

[0048]

EFFECTS OF THE INVENTION By carrying out the present invention, a composition which is flexible, has elongation and has sufficient flame retardancy can be obtained, and there is little smoke and toxic gas generation when burned, and there is no dripping. There is a characteristic. Since the composition of the present invention has a lower content of ammonium sulfate than that of the prior art, it can be suitably used for electric wires and the like with little elution of ammonium sulfate even when used in hot water.

Claims (2)

[Claims] 1. A hard segment of polybutylene terephthalate in which 60 mol% or more of a dicarboxylic acid component and a glycol component are terephthalic acid and tetramethylene glycol, and a soft segment of polyether and / or polyester flexible at room temperature (25 ° C.) A flame-retardant polyester block copolymer composition comprising 100 parts by weight of a polyester block copolymer (A), 1 to 100 parts by weight of ammonium sulfate (B), and 1 to 100 parts by weight of a melamine compound (C). 2. The flame-retardant polyester block copolymer composition according to claim 1, wherein the melamine compound is melamine and / or melamine cyanurate.