KR100430193B1 - Polybutylene Terephthalate Resin Composition - Google Patents

Abstract

The present invention is (A) 40 to 90% by weight polybutylene terephthalate resin, (B) 0.1 to 10% by weight epoxy compound having one epoxy group, (C) 0.1 to 10% by weight epoxy compound having two or more epoxy groups, ( D) 0.01 to 5% by weight of catalyst, (E) 1 to 40% by weight of impact modifier, (F) 0 to 30% by weight of flame retardant, (G) 0 to 10% by weight of flame retardant, and (H) 0 to the total composition The present invention relates to a polybutylene terephthalate resin composition comprising an inorganic filler of about 50% by weight, wherein the epoxy compound containing one or two or more epoxy groups in a polybutadiene terephthalate resin promotes a reaction between an epoxy and a PBT carboxyl terminal group. By using the catalyst, it has the effect of improving the fluidity and impact strength so that injection molding can be performed on a thin molded article while preventing thermal decomposition or hydrolysis of polybutadiene terephthalate by heat. .

Description

Polybutylene Terephthalate Resin Composition

The present invention relates to a polybutylene terephthalate resin composition, and more particularly, by using two or more epoxy compounds and a catalyst in addition to the polybutylene terephthalate resin to improve the long-term heat resistance, heat and moisture resistance of the resin, It relates to a polybutylene terephthalate resin composition excellent in impact strength.

Generally, polybutylene terephthalate resin (hereinafter referred to as PBT resin) has a high crystallization rate, high mechanical fluidity, and is widely used in electric, electronic, automotive, and mechanical parts because of excellent weather resistance, electrical insulation, and abrasion resistance.

Particularly, when reinforcing glass fibers, mechanical properties such as tensile strength and impact strength and basic physical properties such as heat resistance are improved, and physical property change due to hygroscopicity is less than that of glass fiber reinforced nylon resin, and rapid crystallization rate is achieved. It does not require a nucleating agent and shows favorable crystallization behavior even at low mold temperature below 100 ℃.

However, PBT resins have a disadvantage in that they are not easily broken when they are made of a thin molded article, and when used at a high temperature, esters are hydrolyzed even by a small amount of water, and thus, mechanical properties due to molecular weight decrease are rapidly reduced. At this time, the hydrolysis is promoted very quickly by the terminal carboxyl group, and the terminal group can be reduced by using a special additive to the PBT to prevent this.

Japanese Patent Application Laid-Open Nos. 51-91958, 51-5865, 55-82148 and the like have been proposed to use epoxy compounds having 1 to 2 epoxy groups, and in Korean Patent No. 91-6257, an oxazoline compound is used to Although a method of improving heat resistance and hygroscopicity has been proposed, due to the excellent chemical reactivity of the epoxy compound and the oxazoline compound, there is a problem of randomly reacting with PBT, which is a base resin, and promoting the gelation of the resin, thereby degrading moldability.

An object of the present invention is to solve the above problems and to provide a PBT resin composition excellent in mechanical properties, by using an epoxy compound having one epoxy group in the molecule and an epoxy compound having two or more epoxy groups in the molecule, epoxy In order to improve the reactivity of the resin with the carboxyl end groups of the PBT resin, a polybutylene terephthalate resin composition having excellent long-term heat resistance, moist heat resistance and impact strength of the resin is used by using a catalyst which can accelerate the reaction during processing and molding. To provide.

More specifically, the present invention more specifically, (A) 40 to 90% by weight polybutylene terephthalate resin, (B) 0.1 to 10% by weight epoxy compound having one epoxy group, (C) 0.1 epoxy compound having two or more epoxy groups To 10% by weight, (D) 0.01 to 5% by weight of catalyst, (E) 1 to 40% by weight of impact modifier, (F) 0 to 30% by weight of flame retardant, (G) 0 to 10% by weight of flame retardant, and (H It relates to a polybutylene terephthalate resin composition consisting of 0 to 50% by weight of an inorganic filler based on the total composition.

Hereinafter, each component of the present invention will be described in detail.

The polybutylene terephthalate resin (A) used as the base resin in the present invention is obtained from polymerization of dicarboxylic acid and diol. Examples of dicarboxylic acid include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and diphenyl ether dicar. Acids, diphenyldicarboxylic acid, diphenylsulfondicarboxylic acid, and the like. Examples of the diol components include polyethylene, α , ω -diol, that is, ethylene glycol, trimethylene glycol, tetramethylene glycol, and hexamethylene glycol. Neopentyl glycol, cyclohexanedimethylol, 2,2 bis (4- β hydroxyphenyl-phenyl) -propane, 4,4-bis- ( β -hydroxy epoxy) -diphenyl sulfone, diethylene glycol, and the like. Can be mentioned.

Epoxy compound having one epoxy group added in the present invention is a glycidyl ether compound represented by the following formula (1), the addition amount is 0.1 to 10% by weight, more preferably 0.1 to 2% by weight.

[Formula 1]

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

Such glycidyl ether compounds include lauryl glycidyl ether, butylphenyl glycidyl ether, allyl glycidyl ether, stearyl glycidyl ether, methyl glycidyl ether, isobutyl glycidyl ether, and phenyl Glycidyl ether, parachloroglycidyl ether, naphthylglycidyl ether, decylglycidyl ether, glycidyl benzoate, glycidyl butyrate, phenol glycidyl ether and the like.

In general, epoxy resins having two or more functional groups react with the carboxyl end groups in the resin during the molding process to promote gelation, whereas epoxy resins having one reactive functional group do not promote gelation and do not promote gelation. Reacts to reduce the end group content. Therefore, such a performance is not expressed at less than 0.1% by weight, and when the content is more than 10% by weight, there is a disadvantage in that the physical properties of the resin are deteriorated due to the excessive content, so it is most preferable to add it within the range suggested by the present invention. .

Examples of the polyglycidyl ether compound corresponding to the epoxy compound (C) having two or more epoxy groups used in the present invention include a polyglycidylamine compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, and a resorcinol type epoxy. Compound, tetrahydroxy bisphenol F type epoxy compound, cresol noble type epoxy compound, phenol no block type epoxy compound, cycloaliphatic epoxy compound can be selected, the addition amount is 0.1 to 10% by weight, preferably 0.1 to 5% by weight %to be.

The epoxy compound (C) having two or more epoxy groups, like (B), reacts with the carboxyl terminal group of the PBT resin to reduce the content of the terminal carboxyl group, thereby improving the long-term heat resistance and moist heat resistance of the PBT resin, and the impact resistance by the decomposition inhibiting ability. To improve. However, there is a disadvantage in facilitating the gelation of the PBT resin, but by using in combination with the component (B) as in the present invention can solve such problems and can maintain the proper fluidity.

The catalyst (D) used in the present invention is a catalyst for promoting the reaction between the epoxy of the components (B) and (C) and the carboxyl terminal group of the PBT resin, and is preferably lower grades such as phosphoric acid, phosphorous acid, phosphinic acid and phosphonic acid. Alkyl esters, phosphonium compounds, imidazole compounds, trivalent amines, tetravalent ammonium salts and the like can be used, and the amount is 0.001 to 5% by weight.

By using the catalyst within the range proposed in the present invention as described above, not only enhances the reactivity of the epoxy but also undergoes a selective reaction with the carboxyl end groups in the PBT resin, thereby maximizing the efficiency of the epoxy, and extruding Since most of the epoxy proceeds with the reaction in the primary processing process, such as injection molding has the advantage that does not promote the resin gelation in the secondary processing process.

As the impact reinforcing material (E) used in the present invention, it is possible to improve long-term heat resistance and hydrolysis resistance with an olefinic rubber polymer, a styrene rubber polymer and a polyester elastomeric impact reinforcing material.

The olefinic rubber polymer impact modifiers include ethylene propylene copolymer (EPM), ethylene propylene diene copolymer (EPDM), and the like, and styrene-ethylene-butadiene-styrene impact modifiers are also preferable. The polyester elastomeric impact modifier is composed of a polybutylene terephthalate as a hard segment and a polytetramethylene oxide glycol as a soft segment, and the components of the polytetramethylene oxide glycol are 10 to 70% by weight in a total weight ratio. to be.

Flame retardants (F) used in the present invention are brominated epoxy flame retardants or brominated polycarbonate flame retardants. In particular, brominated epoxy flame retardants have excellent electrical insulation and thermal stability of epoxy itself, and when used simultaneously with components (B), (C), (D), and (E), the long-term heat resistance and heat and moisture resistance are greatly improved. It exhibits consistent properties and makes it possible to obtain better compositions.

The brominated epoxy resin flame retardant used in the present invention is a compound having the following formula (2) is used in an amount of 1 to 30% by weight, more preferably 5 to 20% by weight.

[Formula 2]

As the flame retardant aid (G) used in the present invention, antimony trioxide and antimony pentoxide, which are generally used as a flame retardant aid in an epoxy resin composition, are preferable and the amount of use is 1 to 10% by weight.

In the present invention, the glass fiber used as the inorganic filler (H) may be used a common chopped strand, it is also possible to use a coupling agent in order to increase the adhesion with the resin. Other organic fillers may include carbon fiber, boron fiber, potassium titanate, asbestos, calcium carbonate, silicate, alumina, aluminum hydroxide, talc, clay, mica, glass powder, glass beads, barium sulfate, whiskers, and the like.

In addition, stabilizers, antioxidants, mold release agents, anti-dripping agents, pigments, inorganic additives and the like may be added, the content is preferably 0.1 to 2% by weight based on the total composition.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

Examples 1-4 and Comparative Examples 1-5

Each component used in Examples and Comparative Examples of the present invention was quantified as shown in Table 1 below, and then uniformly mixed in a Henschel mixer for 3 to 10 minutes, and then introduced into a twin screw extruder. The glass fiber used as the inorganic filler was put in the middle of the extruder using a side feeder, and the pellet was manufactured by extruding at an extrusion temperature of 240 ° C. and 250 rpm.

The prepared pellets were prepared at 10 Oz injection machine at injection temperature of 240 ° C. and mold temperature of 80 ° C. to prepare the physical specimens, and were then left at 23 ° C. and 50% relative humidity for 40 hours. .

Property measurement method

PBT carboxyl end group content: PBT was dissolved using benzyl alcohol, chloroform, chloroform-methanol as a solvent, and then titrated with sodium hydroxide.

Hydrolysis: The tensile strength test specimens were subjected to a pressure cooking test at 120 ° C. and 2 atm for 100 hours, and then the tensile strength change was measured and compared.

Long-term heat resistance: Tensile strength specimens were measured for 200hr at 180 ° C and the strength decrease was measured.

TABLE 1

As described above, by using an epoxy compound and a catalyst containing one or two or more epoxy groups in the polybutadiene terephthalate resin, the polybutadiene terephthalate is decomposed by heat in the surrounding environment or hydrolyzed by moisture, resulting in mechanical properties. It has the effect of improving fluidity and improving impact strength so that injection molding can be performed on a thin molded article while preventing a disadvantage of deterioration.

Claims (4)

(A) 40-90 weight% of polybutadienetephthalate resins, (B) 0.1 to 10% by weight of an epoxy compound having one epoxy group, (C) 0.1 to 10% by weight of an epoxy compound having two or more epoxy groups, (D) 0.01 to 5% by weight of an epoxy and PBT carboxyl end group reaction catalyst, (E) 1 to 40% by weight of the olefin-based, styrene-based rubber polymer and polyester elastomer-based impact modifier, (F) 0 to 30% by weight of brominated epoxy or brominated polycarbonate oligomer, (G) 0 to 10% by weight of antimony trioxide as a flame retardant, and (H) A polybutylene terephthalate resin composition comprising 3 to 50% by weight of an inorganic filler based on the entirety of (A) (B) (C) (D) (E) (F) (G). The polybutylene terephthalate resin composition according to claim 1, wherein the epoxy compound having one epoxy group is a glycidyl ether compound represented by the following Chemical Formula 1. Formula 1 R ₁ is an aliphatic or aromatic compound or a combination thereof. The epoxy compound according to claim 1, wherein the epoxy compound having two or more epoxy groups is a polyglycidyl ether compound, a polyglycidylamine epoxy compound, a bisphenol A epoxy compound, a bisphenol F epoxy compound, a resorcinol epoxy compound, or tetrahydroxy. A polybutylene terephthalate resin composition selected from the group consisting of bisphenol F type epoxy compounds, cresol novolac type epoxy compounds, phenol novolac type epoxy compounds, and cycloaliphatic epoxy compounds. The polybutylene terephthalate resin composition according to claim 1, wherein the mixing ratio of the epoxy compound having one epoxy group and the epoxy compound having two or more epoxy groups is 0.001 to 99.99% by weight.