KR19990049762A - Polybutylene Terephthalate Resin Composition - Google Patents

Abstract

The present invention provides a polybutylene terephthalate resin composition for use in electrical, electronic and automotive mechanical parts having the following composition, the polybutylene terephthalate resin composition of the present invention is excellent in long-term heat resistance and moisture heat resistance It has the advantage that it can be effectively used for injection molding of thin-walled molded parts by improving the fluidity and impact strength without degrading mechanical properties by degrading by heat or moisture of the environment:

(A) 40 to 90% by weight of PBT resin;

(B) 0.1 to 10.0 wt% of an epoxy compound having one epoxy group;

(C) 0.1 to 10.0% by weight of an epoxy compound having two or more epoxy groups;

(D) 0.01 to 5.0% by weight of epoxy and PBT carboxyl terminal reaction catalyst;

(E) 1.0-30 wt% brominated epoxy;

(F) 1.0-10% by weight of antimony trioxide; And

(G) Glass fiber and inorganic filler 3-50% by weight based on the entirety of (A), (B), (C), (D), (E), and (F).

Description

Polybutylene Terephthalate Resin Composition

The present invention relates to a polybutylene terephthalate (hereinafter referred to as PBT) resin composition, and more particularly, to a polybutylene terephthalate by adding an epoxy compound, an epoxy and a PBT carboxyl end group reaction catalyst, and a brominated epoxy flame retardant. It relates to a polybutylene terephthalate resin composition characterized by improving heat resistance, heat-and-moisture resistance, and moldability.

In general, PBT resin is an engineering plastic that has high crystallization rate and high flowability, and has excellent weather resistance, electrical insulation, chemical resistance, and abrasion resistance, and is widely used in electrical, electronic, and automotive mechanical parts. In particular, PBT resin has the effect of improving the mechanical properties such as tensile strength, flexural strength, impact strength, and basic physical properties such as heat resistance when glass fiber is reinforced. Glass fiber-reinforced PBT resin has very high mechanical strength, less physical property change due to moisture absorption compared to glass fiber-reinforced nylon resin, and crystallization rate is faster than glass fiber-reinforced polyethylene terephthalate resin. It is expected to be a large engineering plastic that can compete with other engineering plastics such as nylon and polycarbonate because it exhibits sufficient crystallization behavior even at low mold temperatures.

However, PBT has a disadvantage in that it is not only broken well in a thin molded article, but also hydrolysis of the ester occurs by a small amount of water at a high temperature, which results in a decrease in the molecular weight of the PBT and a rapid decrease in mechanical properties. There is this. At this time, since hydrolysis is accelerated very quickly by the terminal carboxyl group, a method of reducing the terminal group by employing a special additive to PBT has been proposed to prevent this. However, the above-described method improves long-term heat resistance and heat-and-moisture resistance by reducing the end group of PBT, but has a disadvantage in that molding is difficult by decreasing the fluidity of the PBT resin.

In order to make up for the disadvantages of the above-described PBT resin, Japanese Patent Laid-Open Nos. 51-91958, 51-5865, 55-82148, etc., employ a method of using a compound having 1-2 epoxy groups in one molecule. In Japanese Patent Laid-Open No. 3-9257, a method of improving the long-term heat resistance and heat and humidity resistance of PBT resins using an oxazoline compound has been proposed.

However, when the epoxy compound having one epoxy group is used, the fluidity is excellent, but there is a limit in that the long-term heat resistance and the moist heat resistance are not significantly improved. The epoxy compound and the oxazoline compound having two epoxy groups are excellent in terms of chemical reactivity, There is a problem that the moldability is lowered by randomly reacting to promote gelation of the resin.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems of the prior art as described above, by using an epoxy compound having one epoxy group and an epoxy compound having two or more epoxy reactors and an epoxy and a PBT carboxyl end group reaction catalyst. By controlling the reactivity appropriately, and using a brominated epoxy as the main flame retardant to provide a PBT resin composition not only excellent in moldability but also long-term heat resistance and heat and moisture resistance.

That is, the present invention

(A) 40 to 90% by weight of PBT resin;

(B) 0.1 to 10.0 wt% of an epoxy compound having one epoxy group;

(C) 0.1 to 10.0% by weight of an epoxy compound having two or more epoxy groups;

(D) 0.01 to 5.0% by weight of epoxy and PBT carboxyl end group reaction catalyst;

(E) 1.0-30 wt% brominated epoxy;

(F) 1.0-10% by weight of antimony trioxide; And

(G) Glass fiber and inorganic fillers, characterized in that 3-50% by weight relative to the total (A), (B), (C), (D), (E), and (F) It is providing a polybutylene terephthalate resin composition.

Hereinafter, the present invention will be described in more detail.

The present invention is to provide a polybutylene terephthalate resin composition excellent in impact strength, long-term heat resistance, moist heat resistance and fluidity, the polybutylene terephthalate resin composition of the present invention is a PBT resin, one epoxy group epoxy compound, epoxy group An epoxy compound having two or more thereof, a catalyst which improves the reactivity of the epoxy compound and the carboxyl end groups of the PBT resin, and includes a brominated epoxy as a flame retardant, and antimony trioxide as a flame retardant. Other inorganic fillers are included.

PBT resin (A) used in the present invention can be obtained by polymerization of dicarbonic acid and diol. Examples of the dicarboxylic acid component usable here include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, and the like. Components include polyethylene, α, ω-diol such as ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, cyclohexane dimethylol, 2,2-bis (4-β-hydroxy phenyl- Phenyl) -propane, 4, 4-bis ((beta) -hydroxy epoxy)-diphenyl sulfone, diethylene glycol, etc. are mentioned.

The epoxy compound having one epoxy group included in the composition of the present invention has a structure of Formula 1 below:

Where

R ₁ is an aliphatic or aromatic compound or a compound of the two combined forms.

Examples of such glycidyl ether compounds include lauryl glycidyl ether, butylphenyl glycidyl ether, allyl glycidyl ether, stearyl glycidyl ether, methyl glycidyl ether, isobutyl glycidyl ether, phenyl glycidyl ether, and para. Chlorophenylglycidyl ether, naphthylglycidyl ether, decylglycidyl ether, glycidyl benzoate, glycidyl butylate, phenol glycidyl ether and the like.

Epoxy compound (B) having one epoxy group of Formula 1 has only one reactive functional group, whereas an epoxy resin having at least a bifunctional group reacts with a carboxyl terminal group in the resin to promote gelation during molding. Therefore, it does not promote gelation and reacts with the carboxyl end groups in the resin to reduce the end group content, thereby improving long-term heat resistance and heat and humidity resistance of the resin composition.

The content of the epoxy compound (B) having one epoxy group in the composition of the present invention is 0.1 to 10% by weight, preferably 0.1 to 2% by weight. If the content of the compound (B) in the composition of the present invention is less than 0.1% by weight does not show the gelling performance, if the content exceeds 10% by weight due to the excessive content of the resin does not exhibit the physical properties, such as side effects may occur There is this.

Examples of the epoxy compound (C) having two or more epoxy groups included in the composition of the present invention include polyglycidyl ether compounds, polyglycidylamine epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, and resorcinol type epoxy compounds. And a tetrahydroxy bisphenol F epoxy compound, a cresol novolak type epoxy compound, a phenol novolak type epoxy compound, a cycloaliphatic epoxy compound and the like.

In the present invention, the epoxy compound (C) having two or more epoxy groups reacts with the terminal carboxyl group (-COOH) of PBT like the epoxy compound (B) having one epoxy group to reduce the terminal carboxyl group to prevent hydrolysis, thereby preventing long-term heat resistance of the PBT resin. And it improves the heat and moisture resistance and the impact resistance to improve the decomposition resistance, but has the side effect of promoting PBT gelation by itself, this side effect is prevented by mixing with the epoxy compound (B) having one epoxy group Can be.

In the present invention, the appropriate content of the epoxy compound (C) having two or more epoxy groups is 0.1 to 10% by weight, preferably 0.1 to 5% by weight, and if the content of component (C) is less than 0.1% by weight, long term heat resistance and moisture resistance. When the thermally improving effect is insufficient, on the contrary, when the content exceeds 10% by weight, a problem arises in that the moldability of the resin is poor. In the present invention, the content of the epoxy compound (C) having two or more epoxy groups is within the above range. It is essential.

In the present invention, the mixing ratio of the epoxy compound (B) having one epoxy group and the epoxy compound (C) having two or more epoxy groups is 0.01 to 99.99.

The polybutylene terephthalate resin composition of the present invention includes a reaction catalyst capable of promoting the reaction between the epoxy and the PBT carboxyl end groups, and using such a catalyst not only improves the reactivity of the epoxy, but also PBT. By selectively reacting with the carboxyl end groups in the resin, the efficiency of the epoxy can be maximized, and even a small amount of the epoxy compound can reach an excellent target level, thereby suppressing the gelation of the PBT resin. Furthermore, since most of the epoxy proceeds in the primary processing process such as extrusion, the resin gelation is not promoted during the secondary processing such as injection molding.

Examples of the catalyst (D) used in the present invention as a catalyst for promoting the reaction between the component (B) and (C) epoxy and the carboxyl end groups of the PBT resin include lower alkyl esters such as phosphoric acid, phosphorous acid, phosphinic acid and phosphonic acid. , Phosphonium compounds, imidazole compounds, trivalent amines, tetravalent ammonium salts and the like. Suitable amount of the catalyst (D) in the present invention is 0.001 to 5% by weight. When the amount of the catalyst used in the present invention is outside the above range, the effect intended in the present invention cannot be obtained.

The main flame retardant in the polybutylene terephthalate resin composition of the present invention includes a brominated epoxy flame retardant, the content is 1.0 to 30% by weight, preferably 5 to 20% by weight. The brominated epoxy flame retardant is an epoxy compound (B) having one epoxy group, an epoxy compound having two or more epoxy groups (C), and an epoxy and PBT carboxyl end group reaction catalyst (D) due to its excellent electrical insulation and thermal stability. When used together, the long-term heat resistance and the heat-and-moisture resistance are greatly improved, and thus a better polybutylene terephthalate resin composition can be obtained.

The brominated epoxy flame retardant used as the main flame retardant in the present invention has a structure as shown in the following formula (2).

Where

R ₂ is ego,

R ₃ is _{-Ø (Br) 2 -C (CH} 3) 2 -Ø (Br) 2 - , and (wherein, Ø is benzene),

n is an integer between 1 and 10.

Flame retardant aid (F) in the composition of the present invention contains antimony trioxide in an amount of 1.0 to 10% by weight.

In the present invention, the glass fiber (G) added to improve the mechanical properties and the physical properties of the polybutylene terephthalate may be used a chopped strand cut to a suitable length in ordinary glass roving, and Coupling agents may be used to increase adhesion. Other inorganic fillers include carbon fiber, ceramic fiber, boron fiber, potassium titanate fiber, asbestos, calcium carbonate, silicate, alumina, aluminum hydroxide, talc, clay, mica, glass powder, glass beads, barium sulfate, and heskers. Can be used.

In the polybutylene terephthalate resin composition of the present invention, in addition to the components (A), (B), (C), (D), (E), (F) and (G) described above, normal oxidation is not carried out. Inhibitors, release agents, anti-dripping agents, pigments, inorganic additives and the like may also be added. At this time, the content of each additive is preferably 0.1 to 2.0% by weight based on the total amount of (A), (B), (C), (D), (E), (F) and (G).

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are for illustrative purposes only and should not be construed as limiting the protection scope of the present invention.

Examples 1-4

Among the components of the composition of the composition shown in Table 1, the remaining components except for glass fibers were uniformly mixed for 3 to 10 minutes in a Henschel mixer, and then introduced into a twin screw extruder, and the glass fibers were introduced into the extruder using a side feeder. Extruded at 240 ℃, 250 rpm to produce a pellet. Subsequently, the prepared pellets were injected at an injection temperature of 240 ° C. and a mold temperature of 80 ° C. using a 10 oz injection machine to prepare a physical specimen, and left at 23 ° C. and a relative humidity of 50% for 40 hours, and then measured according to the following method. The results are shown in Table 1 below. In the contents of Table 1, the unit of each component of the composition is weight percent.

<Property evaluation method>

(1) PBT carboxyl end group content: It was measured by dissolving PBT using benzyl alcohol, chloroform and chloroform-methanol as a solvent and titrating with sodium hydroxide.

(2) Moisture and heat resistance: Tensile strength measurement specimens were subjected to a pressure cooking test at 120 ° C. and 2 atm for 100 hours, and then the tensile strength was measured and evaluated, and tensile strength was measured according to ASTM D638. .

(3) Long-term heat resistance: Tensile strength retention was evaluated after 200 hours at 180 ° C.

(4) Fluidity: It was measured by a spiral test (thickness 1.5 mm).

(5) Impact strength: evaluated according to ASTM D256.

Comparative Examples 1 to 7

Except that the composition of the composition was changed as shown in Table 1 below, the same procedure as in Example 1 was carried out to prepare a physical specimen, and after leaving for 40 hours at 23 ℃, 50% relative humidity and then measured the physical properties It is shown together in Table 1 below.

division Comparative Example Example One 2 3 4 5 6 7 One 2 3 4 PBT 49 48 48 48 47 48 48 48 48 48 48 Fiberglass 30 30 30 30 30 30 30 30 30 30 30 Epoxy (1) - 1.0 - - - 0.5 0.5 0.5 0.5 0.5 0.5 Epoxy (2) - - 1.0 - 2.0 0.5 0.5 0.5 - 0.5 - Epoxy (3) - - - 1.0 - - - - 0.5 - 0.5 catalyst - - - - - - - 0.1 0.1 0.1 0.1 Brominated epoxy - - - - - - 15 15 15 15 15 Brominated polycarbonate 15 15 15 15 15 15 - - - - - Antimony trioxide 5 5 5 5 5 5 5 5 5 5 5 Stabilizers and waxes One One One One One One One 0.9 0.9 0.9 0.9 Carboxyl end groups (eq / ton) 62 27 28 22 12 23 22 17 15 12 10 Moisture and heat resistance (%) 38 56 65 70 77 68 73 78 79 81 81 Long-term heat resistance (%) 42 50 53 57 58 52 55 60 62 65 67 liquidity 30 25 20 12 6 22 24 25 20 22 20 Impact Strength (1/8 ") 7.2 8.2 8.0 8.3 8.6 8.3 8.2 8.5 8.5 8.9 9.0 * PBT: Intrinsic viscosity 0.81 * Epoxy (1): Phenol glycidyl ether * Epoxy (2): ADK CIZER EP-17 * Epoxy (3): Cresol novolac epoxy * Brominated epoxy: Molecular weight 20,000 * Brominated polycarbonate: Great lake Stabilizer BC-58 * Stabilizer: Shivagaigi B215 * Wax: Henkel EP861

Since the polybutylene terephthalate resin composition of the present invention uses a mixture of an epoxy compound having one epoxy group and an epoxy compound having two or more epoxy groups, it has excellent long-term heat resistance and heat / moisture heat resistance, so it is decomposed by heat of the surrounding environment or hydrolyzed by moisture. As a result, the mechanical properties are not degraded and flowability and impact strength are improved, and thus, the molded products having the thickness can be injection molded. Furthermore, the brominated epoxy flame retardant used in the composition of the present invention has excellent electrical insulation and thermal stability of the epoxy itself, and when used together with the above two kinds of epoxy compounds and epoxy and PBT carboxyl end group reaction catalysts, the effect of improving long-term heat resistance and moisture and heat resistance Is greatly improved.

In addition, the polybutylene terephthalate resin composition of the present invention to optimize the amount of epoxy available, including a catalyst that can promote the reaction during processing in order to improve the reactivity of the epoxy resin and the carboxyl end groups in the PBT resin In this case, the gelling of the PBT resin is suppressed due to the advantage of reaching an excellent target level even with a small amount of epoxy compound, thereby improving the formability.

Claims (5)

(A) 40 to 90% by weight of PBT resin; (B) 0.1 to 10.0 wt% of an epoxy compound having one epoxy group; (C) 0.1 to 10.0% by weight of an epoxy compound having two or more epoxy groups; (D) 0.01 to 5.0% by weight of epoxy and PBT carboxyl terminal reaction catalyst; (E) 1.0-30 wt% brominated epoxy; (F) 1.0-10% by weight of antimony trioxide; And (G) Glass fiber and inorganic filler Polybutyl, characterized in that composed of 3-50% by weight relative to the total (A), (B), (C), (D), (E), and (F) Renterphthalate resin composition. The polybutylene terephthalate resin composition according to claim 1, wherein the epoxy compound (B) having one epoxy group has a structure represented by the following general formula (1). <Formula 1> Where R ₁ is an aliphatic or aromatic compound or a compound in combination of both. The epoxy compound (C) having two or more epoxy groups is a polyglycidyl ether compound, a polyglycidylamine epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a resorcinol type epoxy compound, and tetra A polybutylene terephthalate resin composition, characterized in that it is selected from the group consisting of a hydroxy bisphenol F type epoxy compound, a cresol novolak type epoxy compound, a phenol novolak type epoxy compound, and a cycloaliphatic epoxy compound. 4. The epoxy and PBT carboxyl end group reaction catalysts are lower alkyl esters such as phosphoric acid, phosphorous acid, phosphinic acid and phosphonic acid, phosphonium compounds, and imidazole compounds. Polybutylene terephthalate resin composition, characterized in that selected from the group consisting of amine, tetravalent ammonium salt. The polybutylene terephthalate resin composition according to any one of claims 1 to 3, wherein the brominated epoxy (E) has a structure represented by the following general formula (2). <Formula 2> Where R ₂ is ego, R ₃ is _{-Ø (Br) 2 -C (CH} 3) 2 -Ø (Br) 2 - , and (wherein, Ø is benzene), n is an integer between 1 and 10.