JP2001072840A - Shockproof polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a shockproof polyester resin composition having an improved impact strength, and suitable for forming a thin formed article such as an IC-card or a tramp card, a communication instrument such as an OA instrument, or the like by melt-kneading a specific epoxidized diene block- copolymer into a polyester resin. SOLUTION: The objective composition, which is free from whitening when deformed by shock, is obtained by melt-kneading (B) an epoxidized diene block- copolymer having an epoxy group on the main chain preferably in an amount of 0.1-30 pts.wt. into (A) 100 pts.wt. of a polyester resin. The component A is preferably a copolymefized polyester of 1,4-cyclohexanedimethanol and polyethylene terephthalate. The component B is preferably a block copolymer consisting of (i) a vinyl aromatic compound (e.g. styrene) and (ii) a conjugated diene compound (e.g. butadiene), and the weight ratio of the component (i) to (ii) is preferably 5/95 to 85/15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin molded article such as an IC card, a playing card, a floppy disk, etc.
The present invention relates to a polyester resin composition suitable for components such as A devices, communication devices such as mobile phones, home electric appliances and the like, and automobile members. More specifically, a polyester resin having improved impact strength by melt-kneading an epoxidized diene-based block copolymer having an epoxy group on the main chain in a polyester resin, and which does not whiten when subjected to deformation due to impact It relates to a resin composition.

[0002]

2. Description of the Related Art Conventionally, polyester resins have been widely used in fields requiring strength and heat resistance, such as automobile interiors and card materials. However, by adding a rubber-like component as an impact modifier to give further strength, physical properties can be improved, but domains are formed as a polymer alloy to form an interface, and impact, deformation, and other factors cause Whitening often occurs due to generation of voids from the interface. In particular, in the transparent field where no pigment is added, slight whitening can greatly reduce the quality of the product.

[0003]

Although it is possible to increase the interfacial strength by using a so-called compatible rubber-like component or by using a compatibilizer, it is possible to increase the short-time strength such as impact. The difference in hardness is a problem for deformation, and voids often occur.

[0004] On the other hand, it is possible to chemically bond the interface by utilizing a reaction. However, it is generally difficult to control the interface, and the interface is hardened, so that voids are more likely to be generated as a result. There's a problem.

Accordingly, an object of the present invention is to provide a polyester resin composition which does not whiten when subjected to deformation due to impact.

[0006]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the reactivity of the epoxy group on the main chain of the polymer was moderate, and the terminal or hydrolysis of the polyester was not achieved. It is noted that it is very sensitive to active species that are sometimes generated. When an epoxidized diene-based block copolymer having an epoxy group on the main chain is added to a polyester resin as a rubber-like component (impact modifier), the epoxy group of this copolymer becomes gentle only at the domain interface. Have been found to react and chemically bond the interface without curing the interface.

The inventor used pulse NMR as a means for efficiently knowing the reaction of an epoxy group at an interface. In the SOLID ECHO method of pulsed NMR, the better the mobility of the molecular chain, the longer the relaxation time of the magnetic spin becomes. Therefore, the mobility distribution of the molecular chain can be known. In the case of the present invention, the polyester resin is a component having low mobility,
The epoxidized diene-based block portion contained in the epoxidized diene-based block copolymer is a rubbery component having high mobility. When the epoxy group reacts with the polyester resin at the interface, the molecular chain near the reaction position of the reacted polyester resin component is incorporated into the rubber component, thereby increasing the mobility of the polyester resin component. Therefore, the reaction amount of the epoxy group at the interface can be observed as a change in the mobility distribution. Then, the ratio of the expected amount of protons of the highly mobile component, which is calculated by multiplying the proton amount measurement result of the resin component alone by the blending ratio, and the actually measured proton amount of the highly mobile component, is calculated at the interface. The effect of the amount of the epoxy group on the polyester resin composition was studied as a value indicating the amount of the epoxy group reacted. As a result, if the reaction amount of the epoxy group is small, the adhesive force at the interface is small, and voids due to peeling are likely to occur. On the other hand, it was revealed that if the reaction amount of the epoxy group was too large, the interface would be hardened and the domain would be less likely to be deformed, so that voids were surely generated during the deformation.
When the value of the reaction amount of the epoxy group (actual measurement of proton amount / expected amount of proton amount) is a specific value, the reforming effect is high such that the polyester resin composition does not whiten when subjected to deformation due to impact. This led to the completion of the present invention.

That is, the present invention relates to a polyester resin,
An object of the present invention is to provide a polyester resin composition obtained by melt-kneading an epoxidized diene-based block copolymer having an epoxy group on a main chain and not whitening when subjected to deformation due to impact. Further, the present invention is characterized in that 0.1 to 30 parts by weight of an epoxidized diene-based block copolymer having an epoxy group on a main chain is melt-kneaded with respect to 100 parts by weight of a polyester resin. The present invention provides a resin composition. Further, the present invention provides the polyester resin composition, wherein 2 to 15 parts by weight of an epoxidized diene-based block copolymer having an epoxy group on a main chain is melt-kneaded with respect to 100 parts by weight of the polyester resin. It provides things. Also, the present invention
The epoxidized diene-based block copolymer is obtained by epoxidizing a block copolymer composed of a block composed of a vinyl aromatic compound and a block composed of a conjugated diene compound, or a partially hydrogenated product thereof. The present invention provides the polyester resin composition having a group. Also, the present invention provides a pulsed NMRSOL
The proton amount of the longest relaxation time component derived from the rubbery component measured at room temperature by the IDECHO method is 1.1 to 3 times the proton amount calculated from the measured value of each resin component and the compounding ratio. The above-mentioned polyester resin composition is provided. Also, the present invention relates to pulsed NMR.
The amount of proton of the longest relaxation time component derived from the rubbery component measured at room temperature by the SOLIDECHO method was 1.2 times smaller than the measured proton amount of each resin component and the proton amount calculated from the compounding ratio.
The present invention provides the polyester resin composition, wherein the ratio is from 1.8 to 1.8 times. The present invention also provides the polyester resin composition, wherein the polyester resin is an amorphous polyester resin or a transparent polyester resin composition mainly composed of the amorphous polyester resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyester resin used in the present invention, a polyester composed of one kind of a dicarboxylic acid and a glycol component or a copolyester composed of a plurality of components can be mentioned. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, succinic acid, sebacic acid, adipic acid, glutaric acid, azelaic acid, and other aromatic dicarboxylic acids and alicyclic dicarboxylic acids. . As the glycol component, diethylene glycol,
Examples include triethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and tetramethylcyclobutanediol.

[0010] Preferred non-crystalline polyester resins used in the present invention are those produced by a condensation reaction of a dicarboxylic acid or a dicarboxylic acid derivative with a diol. More preferred is a copolymerized polyester of 1,4-cyclohexanedimethanol and polyethylene terephthalate, which is disclosed in JP-A-9-509449. In the dicarboxylic acid component of the copolymerized polyester, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid,
An aromatic or alicyclic dicarboxylic acid such as succinic acid, sebacic acid, adipic acid, glutaric acid, azelaic acid and the like may be contained. The glycol component mixture of ethylene glycol and 1,4-cyclohexanedimethanol also contains diethylene glycol, triethylene glycol, propanediol, butanediol, pentanediol, hexanediol, tetramethylcyclobutanediol, etc. in a proportion of 10 mol% or less. It may be.

(Epoxidized diene block copolymer)
Preferred epoxidized diene block copolymers having an epoxy group on the main chain used in the present invention are epoxidized diene block copolymers or partially hydrogenated products thereof.

The term "diene block copolymer" as used herein means a block copolymer comprising a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene compound. Weight ratio of aromatic compound and conjugated diene compound (weight ratio of block copolymer)
Is 5/95 to 85/15, preferably 60/40
８５85/15. The number average molecular weight of the block copolymer used in the present invention is 5,000 to 1,000,000.
0, preferably in the range of 10,000 to 800,000, and the molecular weight distribution [weight average molecular weight (Mw) and number average molecular weight
(Mw / Mn)] is 10 or less. The molecular structure of the block copolymer is linear, for example, X
It is a vinyl aromatic compound (X) block-conjugated diene compound (Y) block copolymer having a structure such as -YX, YXYX, XYXYX, or the like. Further, the unsaturated bond of the conjugated diene compound of the diene-based block copolymer may be partially hydrogenated.

Examples of the vinyl aromatic compound constituting the diene block copolymer include styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, 1,1-
One or more of diphenylstyrene and the like can be selected, and among them, styrene is preferable. As the conjugated diene compound, for example, butadiene, isoprene,
One of 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, phenyl-1,3-butadiene and the like.
Species or two or more species are selected, and among them, butadiene, isoprene and a combination thereof are preferred.

As a method for producing the block copolymer used in the present invention, any production method having the above-mentioned structure can be adopted. For example,
23798, JP-B-47-3252, JP-B-48-
No. 2423, JP-A-51-33184, JP-B-46-
No. 32415, JP-A-59-166518, Japanese Patent Publication No. Sho 4
Nos. 9-36957, JP-B-43-17979, JP-B-46-32415, JP-B-56-28925, and the like. A compound-conjugated diene compound block copolymer can be synthesized.

Further, JP-B-42-8704, JP-B-43-6636, or JP-A-59-133.
According to the method described in JP-A-203, hydrogenation can be carried out in an inert solvent in the presence of a hydrogenation catalyst to synthesize a partially hydrogenated block copolymer for use in the present invention.

The epoxidized diene-based copolymer used in the present invention can be obtained by epoxidizing the above-mentioned diene-based block copolymer.

The epoxidized diene block copolymer in the present invention can be obtained by reacting the above block copolymer with an epoxidizing agent such as hydroperoxides and peracids in an inert solvent. Examples of peracids include formic acid, peracetic acid, and perbenzoic acid. In the case of hydroperoxides, a catalytic effect can be obtained by using a mixture of tungstic acid and caustic soda with hydrogen peroxide, an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tertiary butyl hydroperoxide. .

There is no strict limit on the amount of epoxidizing agent,
The optimal amount in each case will depend on variables such as the particular epoxidizing agent used, the degree of epoxidation desired, the particular block copolymer used, and the like.

The obtained epoxidized diene block copolymer can be isolated by a suitable method, for example, a method of precipitating with a poor solvent, a method of throwing the polymer into hot water with stirring and distilling off the solvent, It can be performed by a direct desolvation method or the like.

The epoxy equivalent of the obtained epoxidized (hydrogenated) diene block copolymer is preferably from 320 to 80.
00 range.

The polyester resin composition of the present invention can be produced by mixing using various known mixers. For example, a method of melt-kneading the components with a tumbling mixer, a Henschel mixer, a ribbon blender, a super mixer, or the like is appropriately selected.

Further, the composition of the present invention may contain, for example, a filler, a curing accelerator, an antioxidant, an ultraviolet absorber, a sulfur curing agent, a decomposition inhibitor, a process oil, a pigment, zinc oxide, stearic acid, Agents, tackifiers, plasticizers, antistatic agents,
Additives used for ordinary thermoplastic materials, such as a flame retardant, a lubricant, a foaming agent, a coloring agent, and a crosslinking aid, can be added alone or in combination as needed. In addition, a thermosetting polymer can be added as long as the properties of the composition of the present invention are not impaired.

As the pulse NMR apparatus used for the measurement in the present invention, any apparatus that is commercially available may be used as long as it can perform the SOLID ECHO method. However,
Since the SOLID ECHO method can capture the change in molecular chain motility due to the residual stress of the measurement sample, the residual stress of the measurement sample is completely removed by heat treatment, and the original properties of the resin without the influence of the residual stress are measured. There is a need to.

The pulsed NMR SOLID EC of the present invention
The proton amount of the long relaxation time component in the HO method
Line based on Lorentz and / or Gaussian distribution
Spin-spin relaxation time T when splitting a peak_TwoIs T_Two
Lorentzian primary decay line> 100 μs integrated
Value. The absolute value of the actual measurement has no meaning,
It is expressed as a molar ratio of the amount of protons with the integrated value being 100%.
You. Such a long T _TwoIs a common hard plastic
It is not present in the molecular chain of the stick,
Such an amorphous phase whose measurement temperature is higher than the glass transition temperature
Observed when present.

[0025]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to the following Examples.

The epoxidized diene-based block copolymer having an epoxy group on the main chain used in the examples was prepared as follows.

Example of Adjustment A jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer was charged with 300 g of polystyrene-polybutadiene block copolymer [Asaflex 810, manufactured by Asahi Kasei Corporation] and 1500 g of ethyl acetate. Dissolved. Then, 165 g of a 30 wt% solution of peracetic acid in ethyl acetate was continuously dropped, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature, taken out of the reactor, and a large amount of methanol was added to precipitate a polymer. The polymer was separated by filtration, washed with water, and dried to obtain an epoxy-modified polymer. The epoxidized diene-based block copolymer having an epoxy group on the main chain thus obtained is referred to as copolymer A (the oxirane oxygen concentration of copolymer A was 2.1 wt%).

Example 1 Amorphous polyester resin (PET-G, manufactured by Eastman Chemical Company) 90
Pellets (hereinafter, referred to as A pellets) were prepared by kneading 10 parts by weight of the copolymer A obtained in the Preparation Example with respect to parts by weight. The A pellet was formed into a color plate, a drop weight impact test was performed on a portion having a thickness of 1 mm, and the total light transmission amount of the deformed portion was divided by the total light transmission amount of the undeformed portion to calculate a rate of change. Further, the color plates before and after the falling weight impact test were respectively broken under cooling, and the broken surfaces were observed with a scanning electron microscope. As a result of observing the interface with a scanning electron microscope, almost no voids were observed. The rate of change in the total amount of transmitted light was 96%.

On the other hand, the pellets of the A pellet and the pellet of the copolymer A were heat-treated at 130 ° C. for 24 hours under vacuum for 24 hours to completely remove the residual stress, and the proton amount was measured by pulse NMR using as a sample. Table 1 shows the results. The proton amount of the longest relaxation time component of the A pellet by pulse NMR was 1.41 times the value calculated from the blending ratio of the A pellet.

[Comparative Example 1] Amorphous polyester resin (PET-G, manufactured by Eastman Chemical Company) 90
Parts by weight of a diene-based block copolymer (Asahi Kasei,
Asaflex 810) was prepared by kneading 10 parts by weight of pellets (hereinafter referred to as B pellets). The B pellet was formed into a color plate, a drop weight impact test was performed on a portion having a thickness of 1 mm, and the total light transmittance change rate and the fracture surface were observed by a scanning electron microscope in the same manner as in Example 1. As a result, the rate of change in the total amount of transmitted light was 37%. When observed with a scanning electron microscope, the interface was clearly confirmed and a large amount of voids were observed.

On the other hand, B pellet and Asaflex 8
Each of the 10 pellets was heat-treated at 130 ° C. for 24 hours under vacuum to completely remove the residual stress, and the amount of protons was measured by pulse NMR using as a sample. Table 1 shows the results. The proton amount of the longest relaxation time component of the B pellet by pulse NMR was 0.97 times the value calculated from the blending ratio of the B pellet.

[0032]

[Table 1]

[0033]

According to the present invention, a polyester resin composition obtained by melt-kneading the polyester resin of the present invention and an epoxidized diene-based block copolymer having an epoxy group on the main chain is not whitened even when an impact is applied. As a result of observing the cross section of the resin composition after the impact test with an electron microscope, it was confirmed that almost no voids were generated.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph of a cut surface of a color plate before a falling weight impact test of Example 1.

FIG. 2 is a scanning electron micrograph of a cut surface of a color plate after a falling weight impact test of Example 1.

FIG. 3 is a scanning electron micrograph of a cut surface of a color plate before a falling weight impact test of Comparative Example 1.

FIG. 4 is a scanning electron micrograph of a cut surface of a color plate after a falling weight impact test of Comparative Example 1.

Claims (7)

[Claims] 1. A polyester resin composition comprising a polyester resin melt-kneaded with an epoxidized diene-based block copolymer having an epoxy group on a main chain, wherein the polyester resin composition does not whiten when subjected to impact deformation. object. 2. 100 parts by weight of a polyester resin,
The polyester resin composition according to claim 1, wherein 0.1 to 30 parts by weight of an epoxidized diene-based block copolymer having an epoxy group on a main chain is melt-kneaded. 3. 100 parts by weight of the polyester resin,
The polyester resin composition according to claim 1, wherein 2 to 15 parts by weight of an epoxidized diene-based block copolymer having an epoxy group on a main chain is melt-kneaded. 4. The epoxidized diene-based block copolymer is obtained by epoxidizing a block copolymer composed of a block composed of a vinyl aromatic compound and a block composed of a conjugated diene compound or a partially hydrogenated product thereof. The polyester resin composition according to any one of claims 1 to 3, wherein the polyester resin composition has an epoxy group on a main chain. 5. The amount of protons of the longest relaxation time component derived from the rubbery component measured at room temperature by pulsed NMR SOLID ECHO method is 1.1 times smaller than the measured value of each resin component and the amount of protons calculated from the compounding ratio. The polyester resin composition according to any one of claims 1 to 4, wherein the ratio is double to triple. 6. The amount of protons of the longest relaxation time component derived from the rubbery component measured at room temperature by the pulsed NMR SOLID ECHO method is 1.2 times smaller than the measured value of each resin component and the proton amount calculated from the compounding ratio. The polyester resin composition according to any one of claims 1 to 4, wherein the ratio is from 1.8 to 1.8 times. 7. The polyester resin according to claim 1, wherein the polyester resin is an amorphous polyester resin or a transparent polyester resin composition mainly composed of the amorphous polyester resin.
7. The polyester resin composition according to any one of items 1 to 6.