KR100241491B1 - Thermoplastic resin composition with excellent hydrothermal stability - Google Patents

Abstract

The thermoplastic resin composition of the present invention (A) 20 to 80 parts by weight of polybutylene terephthalate resin; (B) 80 to 20 parts by weight of a polycarbonate resin; (C) a reactive copolymer comprising a core portion and a shell portion, wherein the core portion is selected from the group consisting of butadiene rubber, acrylate rubber, silicone rubber and mixtures thereof, and glycidyl methacrylate in the shell portion 5 to 30 parts by weight; And (D) 5 to 50 parts by weight of glass fibers based on 100 parts by weight of the total resin composition; It is a thermoplastic resin composition excellent in the hydrothermal stability characterized by the above-mentioned.

The thermoplastic resin composition of the present invention may be added with flame retardants, flame retardant aids, inorganic additives, heat stabilizers, antioxidants, light stabilizers, lubricants, pigments and / or dyes according to their respective uses.

Description

[Name of invention]

Thermoplastic resin composition with excellent hydrothermal stability

Detailed description of the invention

[Field of Invention]

The present invention relates to a thermoplastic resin composition having excellent hydrothermal stability.

More specifically, the present invention is a thermoplastic resin having excellent hydrothermal stability consisting of a polybutylene terephthalate (PBT) resin, a polycarbonate (PC) resin, a reactive copolymer containing glycidyl methacrylate (GMA), and glass fibers. To a composition.

[Background of invention]

In general, polybutylene terephthalate resin has a high crystallization rate, excellent fluidity, excellent weather resistance, electrical insulation, chemical resistance, and abrasion resistance has been widely used in applications such as electrical, electronic and automotive machinery parts. As is commonly seen in conventional crystalline resins, when the polybutylene terephthalate resin is reinforced with glass fibers, the basic physical properties of the resin such as mechanical strength and heat resistance such as tensile strength, flexural strength, and impact strength are improved. Cause. In particular, glass fiber-reinforced polybutylene terephthalate resin has a smaller change in physical properties due to moisture absorption than glass fiber-reinforced nylon resin, and has a faster crystallization rate than glass fiber-reinforced polybutylene terephthalate (PET) resin. In addition, it can exhibit sufficient crystallinity even at low mold temperature below 120 ° C.

As described above, the glass fiber reinforced polybutylene terephthalate resin has excellent properties compared to the conventional glass fiber reinforced nylon resin or polyethylene terephthalate resin, and also has excellent mechanical strength, heat resistance, and moldability, and its use has been increased. .

However, the glass fiber-reinforced polybutylene terephthalate resin is formed inside the molding due to the interaction of the shrinkage stress caused by the crystallization of the polybutylene terephthalate resin and the glass fiber arrangement when the molten resin composition is solidified during the injection molding There is a disadvantage that the internal stress occurs in each part of the molding, and after the molding is taken out of the mold, warpage occurs in the molding.

In Japanese Laid-Open Patent Publication No. 52-121659, an improved method of alloying with a polycarbonate resin is provided to compensate for the impact resistance. However, the ester linkages of polybutylene terephthalate resin and polycarbonate resin are susceptible to hydrolysis, so that when exposed to resin products for a long time under hot water and high temperature and high humidity conditions, the molecular weight decreases due to breakage of the main chain, resulting in strength, rigidity, and It causes a decrease in physical properties such as impact resistance.

Accordingly, the present inventors have developed a thermoplastic resin composition having excellent thermal stability by using a polycarbonate resin, a reactive copolymer containing glycidyl methacrylate, and glass fiber in a polybutylene terephthalate resin to solve the above problems. It came to the following.

[Purpose of invention]

An object of the present invention is to provide a thermoplastic resin composition having excellent hydrothermal stability consisting of a polybutylene terephthalate resin, a polycarbonate resin, a reactive copolymer containing glycidyl methacrylate, and glass fibers.

[Summary of invention]

The thermoplastic resin composition of the present invention (A) 20 to 80 parts by weight of polybutylene terephthalate resin; (B) 80 to 20 parts by weight of a polycarbonate resin; (C) a reactive copolymer comprising a core portion and a shell portion, wherein the core portion is selected from the group consisting of butadiene rubber, acrylate rubber, silicone rubber and mixtures thereof, and glycidyl methacrylate in the shell portion 5 to 30 parts by weight; And (D) 5 to 50 parts by weight of glass fibers based on 100 parts by weight of the total resin composition; It is a thermoplastic resin composition excellent in the hydrothermal stability characterized by the above-mentioned.

Inorganic additives, heat stabilizers, antioxidants, light stabilizers, pigments and / or dyes may be added to the thermoplastic resin composition of the present invention depending on the respective use.

Detailed Description of the Invention

The thermoplastic resin composition excellent in the hydrothermal stability of the present invention comprises (A) a polybutylene terephthalate resin, (B) a polycarbonate resin, (C) a reactive copolymer containing glycidyl methacrylate, and (D) a glass fiber. Is done. Description of each of these components is as follows.

(A) polybutylene terephthalate resin

Polybutylene terephthalate resin is a polymer of dicarboxylic acid and diol.

The dicarboxylic acid includes terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, and the like.

The diols include polyethylene, α, ω-diol, ie ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycone, cyclohexane dimethylol, 2,2 bis (4-βhydroxy phenyl- Phenyl) propane, 4,4-bis- (β-hydroxyepoxy) diphenyl sulfone, diethylene glycol, and the like.

In the present invention, the polybutylene terephthalate resin is used in 20 to 80 parts by weight. When the polybutylene terephthalate resin is used in an amount of 80 parts by weight or more, it is excellent in heat resistance and chemical resistance, so that the properties of the crystalline resin can be well utilized, but warpage of moldings is likely to occur during molding. In addition, when the polybutylene terephthalate resin is used in an amount of 20 parts by weight or less, the impact resistance is excellent and the occurrence of warpage of the molded product can be suppressed, but the physical properties such as heat resistance and chemical resistance are reduced.

(B) polycarbonate resin

In the present invention, the polycarbonate resin may be a homogeneous polycarbonate, polycarbonate copolymer, and polycarbonate terpolymer, or a mixture thereof.

Conventionally, polycarbonate resins can synthesize phosgene and dihydroxy compounds using interfacial polycondensation (German Patent Nos. 2063050, 2062305, 1570703, and 2211956, French Patent No. 15,561, H). Schnell, “Chemistry and Physics of Polycarbonates”; published in Interscience, 1964). In addition, condensation polymerization by the transesterification method disclosed in US Pat. Nos. 30,383, 2,99,597, 3248414 and the like can also be used.

Examples of the dihydroxy compounds used to synthesize the polycarbonate resins used in the present invention include hydro, quinone, risoxinol, bis (hydr) disclosed in US Pat. Nos. 3028365, 2999835, and 2991273. Hydroxyphenyl) ether, bis (hydroxyphenyl) ketone, bis (hydroxyphenyl) sulfone, a, a-bis (hydroxyphenyl) diisopropylbenzene and the like and 2,2-bis (4-hydroxyphenyl) propane ( Bisphenol A), 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) cyclohexane, a, a-bis (4-hydroxyphenyl)- p-diisopropylbenzene, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, bis-3,5-dimethyl 4-hydroxyphenyl) methane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis (3-methyl-4-hydroxyphenyl) sulfoxide Id, bis (3-methyl-4-hydroxyphenyl] -sulfone, hydroxybenzophenol, 2,4-bis- (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,1 -Bis (3,5-dimethyl-4-hydroxyphenol) cyclohexane, etc. Among them, 2,2-bis (3,5-dimethylhydroxyphenyl) propane and 1,1-bis (4-hydroxy Phenyl) cyclohexane is preferred, with 2,2-bis (4-hydroxyphenyl) propane being the most preferred dihydroxy compound.

The polycarbonate resin used in the present invention may have a structure derived from one or more of the dihydroxy compounds exemplified above, and may have a branch structure using the polyhydroxy compound. In addition, polycarbonate resins based on phenolphthalein, polycarbonate copolymers, polycarbonate terpolymers, and the like may also be used.

The polycarbonate resin is preferably used in 20 to 80 parts by weight.

(C) a reactive copolymer containing glycidyl methacrylate

The reactive copolymer containing glycidyl methacrylate used in the present invention is a core-shell copolymer.

The core component of the copolymer may be a rubber component having a glass transition temperature of 0 ° C. or less to have characteristics of an elastomer. The rubbery components include butadiene-based, acrylate-based and silicone-based rubbers having conjugated diene bonds. As the butadiene rubber, diene rubbers such as styrene / butadiene and acrylonitrile / butadiene copolymerized with other monomers copolymerizable with butadiene may be used, and as the acrylate rubber, metal acrylate, methyl methacrylate, methyl acrylate , Butyl acrylate, propyl acrylate, isopropyl acrylate, isobutyl acrylate and the like can be used. A core component can use not only said single component but a mixture thereof.

As the core component used in the present invention, a silicone rubber which is a mixture of silicone and butadiene is preferable.

In the present invention, the shell component of the copolymer is composed of a copolymer of glycidyl methacrylate and acrylate.

The acrylate used for the shell includes metal acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, propyl acrylate, isopropyl acrylate, isobutyl acrylate and the like. Among them, it is preferable to use methyl methacrylate.

The epoxy reactor contained in glycidyl methacrylate chemically reacts with the matrix resin (PBT / PC resin) to prevent the molecular chain of the resin from being cut by hot water, thereby preventing the physical properties such as strength and impact resistance from being lowered. .

In the composition of the present invention, the reactive copolymer containing glycidyl methacrylate in the shell may not ensure sufficient water resistance when used at 5 to 30 parts by weight or less, and when used at 30 parts by weight or more, It results in deterioration of physical properties and chemical resistance.

(D) glass fiber

Glass fiber is added to improve mechanical properties and heat resistance, such as tensile strength, flexural strength, and impact strength, of the resin composition.

In the present invention, the glass fiber may be a chopped strand, and a coupling agent may be used together to improve adhesion.

Glass fibers are preferably added in 5 to 50 parts by weight of the total resin composition.

The thermoplastic resin composition of the present invention may be added with flame retardants, flame retardant aids, inorganic additives, heat stabilizers, antioxidants, light stabilizers, lubricants, pigments and / or dyes according to their respective uses.

The thermoplastic resin composition of the present invention is mixed with a polycarbonate resin to a polybutylene terephthalate resin, by using a reactive copolymer containing glycidyl methacrylate in the shell to give thermal stability, and by using glass fiber as an impact modifier Not only is it excellent in stability but also has strength, rigidity and impact resistance.

In the thermoplastic resin composition of the present invention, a polycarbonate resin, a reactive copolymer including glycidyl methacrylate, and a glass fiber are added to a polybutylene terephthalate resin, mixed with a glass fiber, and necessary additives such as a flame retardant are added to the mixture. Then mix into a conventional mixer. This mixture is prepared into pellet resin composition through an extruder.

The invention can be better understood by the following examples, which are intended for purposes of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

EXAMPLE

Reactive copolymers comprising (A) polybutylene terephthalate resin, (B) polycarbonate resin, (C) glycidyl methacrylate in the resin compositions of Examples 1 and Comparative Examples 1 and 2 below, and (D) The manufacture and specification of glass fibers are as follows.

Example 1

47 parts by weight of polybutylene terephthalate resin, 35 parts by weight of polycarbonate resin, and 18 parts by weight of a reactive copolymer containing glycidyl methacrylate (using METHABLEN KS 4015 manufactured by MRC of Japan) were mixed and 100 parts by weight of this mixture 0.3 parts by weight of octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenylpropiorate) as a hindered phenolic stabilizer, and mono and di-stearyl acid as phosphorus stabilizers 0.3 parts by weight of phosphate was added and uniformly mixed in a Henschel mixer for 5 minutes, and then introduced into a twin screw extruder of L / D 29 and, = 40 mm. Glass fibers were fed into the middle of the extruder through a side feeder and the feed amount was 15 parts by weight of the total resin. After the test specimens were prepared at the injection temperature of 240 ° C., the specimens were kept at 23 ° C. and 50% relative humidity for 40 hours, and then the tensile strength was measured according to ASTM.

Heat-resistant water resistance was measured by immersing the tensile test specimen in a water bath (sample) at regular intervals while maintaining a constant temperature at 80 ℃.

Comparative Example 1

57 parts by weight of polybutylene terephthalate resin and 43 parts by weight of polycarbonate resin were mixed and octadecyl-3- (3,5-di-t-butyl- as a hindered phenolic stabilizer based on 100 parts by weight of the mixture. 4-hydroxyphenyl phenyl propioate) 0.3 parts by weight, and 0.3 parts by weight of mono- and di-stearyl acid phosphate as phosphorus stabilizers were added and uniformly mixed in a Henschel mixer for 5 minutes, and then L / S 29, ￠ = 40 mm twin screw extruder Was put in. Glass fibers were fed into the middle of the extruder through a side feeder and the feed amount was 15 parts by weight of the total resin. After the test specimens were prepared at the injection temperature of 240 ° C., the specimens were kept at 23 ° C. and 50% relative humidity for 40 hours, and then the tensile strength was measured according to ASTM.

Heat-resistant water resistance was measured by immersing the tensile test specimen in a water bath and sampling at regular intervals while keeping it constant at 80 ° C.

That is, in Comparative Example 1, the reactive copolymer containing glycidyl methacrylate (KS 4015) was not added, and the preparation of the physical specimens and the measurement method of the physical properties were the same as in Example 1.

Comparative Example 2

47 parts by weight of polybutylene terephthalate resin, 35 parts by weight of polycarbonate resin, and 18 parts by weight of impact modifier (S-2001) containing no glycidyl methacrylate were mixed, and 100 parts by weight of the mixture was hindered ( 0.3 parts by weight of octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenylpropioate), a phenolic stabilizer, and 0.3 parts by weight of mono and di-stearyl acid phosphates, which are phosphorus stabilizers The mixture was added and mixed uniformly in a Henschel mixer for 5 minutes, and then introduced into a twin screw extruder having an L / D of 29 and ￠ = 40 mm. Glass fibers were fed into the middle of the extruder through a side feeder and the feed amount was 15 parts by weight of the total resin. After the test specimens were prepared at the injection temperature of 240 ° C., the specimens were kept at 23 ° C. and 50% relative humidity for 40 hours, and then the tensile strength was measured according to ASTM.

Heat-resistant water resistance was measured by immersing the tensile test specimen in a water bath and sampling at regular intervals while keeping it constant at 80 ° C.

That is, in Comparative Example 2, the polybutylene terephthalate resin and the polycarbonate resin have the same composition as in Example 1, but the glycidyl methacrylate-containing reactive copolymer does not contain glycidyl methacrylate. It was added in place of the reinforcing material (S-2001), except that the physical properties of the resin composition was prepared in the same manner as in Example 1 and the physical properties were measured.

The composition of each component used in Example 1 and Comparative Examples 1 and 2 is shown in Table 1.

TABLE 1

Note) The above figures are all parts by weight

Tensile strength was measured for the test pieces of the resin composition prepared according to Example 1 and Comparative Examples 1 and 2, and the results for the tensile strength retention were shown in Table 2.

TABLE 2

Note) # Tensile strength retention unit: (%)

As can be seen in Table 2 of the resin composition prepared according to Example 1 of the present invention, it is understood that the tensile strength is not large with a change in time, so that the stability in hot water is excellent.

In Comparative Example 1, compared with Example 1, the resin composition can be seen that the tensile strength rapidly decreases with time (96 → 57, 91 → 41, 68 → 35 and 58 → 22). Therefore, it can be seen that the reactive copolymer containing glycidyl methacrylate improved the hydrothermal stability of the resin composition.

In Comparative Example 2 instead of the reactive copolymer KS 4015 containing the glycidyl methacrylate used in Example 1 with a resin composition using the impact modifier S-2001 containing no glycidyl methacrylate, Comparative Example Compared to 1, the decrease in tensile strength is not large, but the retention rate of tensile strength is significantly reduced (96 → 78, 91 → 53, 69 → 46 and 58 → 31) than in Example 1. Therefore, it can be seen that the role of improving the hydrothermal stability of the resin composition also depends on the kind of reactive copolymer used.

Simple modifications or changes of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (3)

(A) 20 to 80 parts by weight of polybutylene terephthalate resin; (B) 80 to 20 parts by weight of a polycarbonate resin; (C) a reactive copolymer comprising a core part and a shell part, wherein the core part is selected from the group consisting of butadiene rubber, acrylate rubber, silicone rubber and mixtures thereof, and glycidyl methacrylate in the shell part 5 to 30 parts by weight; And (D) 5 to 50 parts by weight of glass fibers based on 100 parts by weight of the total resin composition; The thermoplastic resin composition excellent in the hydrothermal stability characterized by consisting of. The thermoplastic resin composition of claim 1, wherein the shell portion of the reactive copolymer comprises a copolymer of glycidyl methacrylate and acrylate. The thermoplastic resin composition of claim 1, wherein a flame retardant, a flame retardant aid, an inorganic additive, a heat stabilizer, an antioxidant, a light stabilizer, a lubricant, a pigment, and / or a dye are further selectively added to the thermoplastic resin composition. Resin composition.