JPH07331023A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition, comprising a polycarbonate-based resin and a specific modified block copolymer in a specified proportion, improved in impact resistance at low temperatures without causing the delamination and useful for electrical and electronic parts, etc. CONSTITUTION:This resin composition comprises (A) 95-30 pts.wt. polycarbonate- based resin and (B) 5-70 pts.wt. of (i) a modified block copolymer having hydroxyl groups at the terminals of a block copolymer containing one or more blocks A selected from a polymer block consisting essentially of an aromatic vinyl compound and a hydrogenated polybutadiene block obtained by hydrogenating a polybutadiene having <=20% content of 1,2-bonds and one or more blocks B such as a hydrogenated polyisoprene block or a hydrogenated polybutadiene block prepared by hydrogenating a polybutadiene having 30-70% content of the 1,2-bonds and/or (ii) a modified block copolymer having hydroxyl groups at the terminals of a block copolymer containing one or more polymer blocks C consisting essentially of the aromatic vinyl compound and one or more polyisobutylene blocks D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition comprising a polycarbonate polymer and a mixture of a specific block copolymer having a hydroxyl group at the terminal.

[0002]

2. Description of the Related Art Polycarbonate polymers have excellent properties such as transparency, impact resistance, heat resistance and dimensional stability, and are used in a wide variety of fields such as electricity, electronics and automobiles. However, this excellent impact resistance also remarkably deteriorates in the low temperature region. An elastomer such as a hydrogenated product of a styrene-conjugated diene copolymer may be added for the purpose of improving the low temperature impact resistance. However, the method of adding this elastomer has problems that the effect of improving impact resistance at low temperature is insufficient, the compatibility is not sufficient, and delamination occurs in the molded body.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to obtain a thermoplastic resin composition comprising a polycarbonate polymer having improved impact resistance at low temperatures without delamination.

[0004]

According to the present invention, the above object is achieved by a composition in which a block copolymer having a hydroxyl group at a terminal is mixed with a polycarbonate resin.

More specifically, it is selected from the group consisting of a polymer block composed mainly of a polycarbonate resin and an aromatic vinyl compound and a hydrogenated polybutadiene block obtained by hydrogenating a polybutadiene having a 1,2-bond content of 20% or less. At least one block A, a hydrogenated polyisoprene block, a hydrogenated polybutadiene block obtained by hydrogenating a polybutadiene having a 1,2-bond content of 30 to 70%, and hydrogenated isoprene and butadiene At least one mainly composed of a modified block copolymer having a hydroxyl group at the terminal of a block copolymer containing at least one block selected from the group consisting of random copolymer blocks of A polymer block of at least 1
This is achieved by a composition containing a modified block copolymer having a hydroxyl group at a terminal of a block copolymer containing one polyisobutylene block.

The present invention will be described in detail below.

The polycarbonate resin used as the component (a) in the resin composition of the present invention is a polymer having a carbonic acid ester structure in the main chain, and is bisphenol A.
The carbonic acid ester structure of is used.

The block copolymer having a hydroxyl group at the terminal of the component (b) used in the resin composition of the present invention can be obtained by an anionic polymerization method or a cationic polymerization method.

The block copolymer having a hydroxyl group at the terminal obtained by the anionic polymerization method is an aromatic compound such as styrene, α-methylstyrene, 3-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene and 2-vinylnaphthalene. A block obtained by polymerizing vinyl, or one or more blocks (block A) selected from polybutadiene blocks obtained by polymerizing a butadiene monomer such that 1,4 bonds are 60% or more; 1,2 bond or 3, with isoprene block or isoprene monomer
Polyvinyl isoprene block polymerized to have 4 bonds of 30% to 60%, or a random copolymer block of isoprene and butadiene, or butadiene monomer having 1,2 bonds of 30% to 60% A hydroxyl group is added to the end of a block copolymer having at least one block (block B) selected from the polymerized polyvinyl butadiene blocks, and the double bond in the block composed of a conjugated diene is hydrogenated. It was done.

In the block copolymer having a hydroxyl group at the terminal, the block A and the block B are (AB) p-
OH, (BA) q-OH, A (BA) r-OH, and B (AB) s-OH (in the formula, p, q, r, and s each represent an integer of 1 or more, and OH represents a hydroxyl group. ) Has a structure represented by. Although p, q, r and s can be arbitrarily determined, they are usually selected from the range of 5 or less. The block copolymer having a hydroxyl group at the terminal may be used in a state where two or more kinds of block copolymers having a hydroxyl group at the terminal are mixed depending on the case.

Such a block copolymer having a hydroxyl group at the terminal can be obtained by obtaining a polymer by anion living polymerization or the like using a commonly used organic alkali metal catalyst, adding a hydroxyl group to the terminal, and then hydrogenating the polymer. . For example, (AB) p-OH, or A (BA) r-O
To polymerize H, a saturated aliphatic hydrocarbon compound such as hexane, heptane, or cyclohexane using an anionic polymerization initiator such as n-butyllithium or s-butyllithium,
Alternatively, a living polymer is produced by anionically polymerizing an aromatic vinyl monomer or a butadiene monomer using an aromatic hydrocarbon compound such as benzene or toluene as a solvent under a temperature condition of 30 to 60 ° C. Then, an isoprene monomer is dropped into the system to obtain a binary block copolymer. Furthermore, if an aromatic vinyl monomer or a butadiene monomer is dropped again into the system, a ternary block copolymer can be produced. By repeating this operation, a block copolymer of 4 or more elements is obtained. On the other hand, (BA) q-OH or B
To polymerize (AB) s-OH, a living polymer is produced by anionically polymerizing an isoprene monomer, and then an aromatic vinyl monomer or butadiene is dropped into the system to form a binary block copolymer. To get Furthermore, a ternary block copolymer can be produced by dropping the conjugated diene-based monomer again into the system. Repeat this operation 4
An original or higher block copolymer is obtained. The polyvinyl butadiene block can be obtained by adding dioxane or tetrahydrofuran to the system in an appropriate amount and dropping a butadiene monomer. Similarly, the polyvinyl isoprene block can be obtained by adding an appropriate amount of dioxane or tetrahydrofuran to the system and dropping the isoprene monomer. Then, when the block copolymer reaches a desired molecular structure and molecular weight, ethylene oxide or propylene oxide is added, and then alcohols, carboxylic acids, water, etc. are added to terminate the polymerization.

Subsequently, the obtained copolymer is hydrogenated to produce a block copolymer having a hydroxyl group at the terminal. A homogeneous catalyst or a heterogeneous catalyst can be used as the hydrogenation catalyst. When using a homogeneous catalyst, an organic transition metal catalyst (for example, nickel acetylacetonate,
Cobalt acetylacetonate, nickel naphthenate,
0.01 to 0.1 mol% per double bond of the polymer subjected to hydrogenation of a Ziegler catalyst or the like, which is a combination of an alkyl compound of a metal such as cobalt naphthenate) and aluminum, an alkali metal or an alkaline earth metal Use to some extent. Hydrogenation reaction is from room temperature to 150 ° C, normal pressure to 50 kg / cm
It is carried out under a hydrogen pressure of 2 and is completed in about 1 to 50 hours.
After completion of the reaction, acidic water is added to the vessel and vigorously stirred to dissolve the hydrogenation catalyst in water. Phase separated 2
By removing the aqueous phase from the phases and further distilling off the solvent,
A block copolymer having a hydroxyl group at a desired end is obtained.

In the block copolymer having a hydroxyl group at the terminal used in the present invention, it is necessary that 50% or more of the carbon-carbon double bond in the block composed of the conjugated diene monomer is hydrogenated. From the viewpoint of deterioration and weather resistance, the hydrogenation rate is preferably 80% or more.

The block copolymer having a hydroxyl group at the terminal obtained by the cationic polymerization method is an aromatic vinyl compound such as styrene, α-methylstyrene, p-methylstyrene, pt-butylstyrene or p-chlorostyrene. Copolymerization of a block obtained by polymerizing one or more kinds or a block obtained by polymerizing indene and its derivative (block A) and a polyisobutylene block obtained by polymerizing isobutylene (block B) A hydroxyl group is added to the end of the united product.

The block copolymer having a hydroxyl group at the terminal is obtained by a conventional cationic living polymerization using 1,4-di (2-methoxy-2-propyl) benzene or the like, and a hydroxyl group is added to the terminal. Obtained by For example, in order to obtain a styrene-isobutylene-styrene triblock copolymer, 1,4-di (2-methoxy-) is used in a solvent of cycloalkane such as cyclohexane and methylcyclohexane, or halogenated alkane such as methyl chloride and methylene chloride. A living polymer is produced by cationically polymerizing a monomer of isobutylene under the temperature condition of -10 ° C to -90 ° C using 2-propyl) benzene and titanium tetrachloride as an initiator, and then N, N-dimethylacetamide and After adding 2,6-di-t-butylpyridine, a styrene monomer is dropped into the system to obtain a styrene-isobutylene-styrene triblock copolymer having chlorine at both ends. By repeating this operation, a block copolymer of 5 or more units is obtained. Then, dehydrochlorination, hydroboration, and oxidation are performed to obtain a styrene-isobutylene-styrene triblock copolymer having hydroxyl groups at both ends.

The hydroxyl group of the block copolymer having a hydroxyl group at the terminal may be added to either the block A terminal or the block B terminal, but it is preferable that the hydroxyl group is added to the terminal of the block A, which is a hard block. The one added to the end of the block is most preferably used. The number average molecular weight of the block A of the block copolymer having a hydroxyl group at the terminal is preferably in the range of 5,000 to 50,000. The number average molecular weight of block B is 10,000
It is preferably in the range of -100,000. Further, the number average molecular weight of the entire block copolymer is 15,000 to 1500.
Those in the range of 00 are used. The weight ratio of block A to block B is not particularly limited, but is 1: 9 to 7:
Those in the range of 3 are preferably used.

The concentration of terminal OH groups must be 0.5 or more per molecule. When the concentration of OH groups is less than the above range, it becomes difficult to maintain high mechanical properties of the composition of the present invention. From this viewpoint, the concentration of OH groups is more preferably 0.75 or more.

In the polymer composition of the present invention, the weight ratio of the polycarbonate resin to the block copolymer having a hydroxyl group at the end must be in the range of 95/5 to 30/70. In the resin composition finally obtained in which the proportion of the block copolymer having a hydroxyl group at the end is less than 5% by weight, the impact resistance improving effect becomes small, which is not preferable. On the other hand, if the amount exceeds the above range, the composition obtained by mixing will have a large decrease in elastic modulus and mechanical strength, which is not preferable. From this viewpoint, the ratio is more preferably 90/10 to 60/40.

The resin composition of the present invention can be produced by mixing the above-mentioned three kinds of components and, if necessary, other additives simultaneously or sequentially and melt-kneading by a conventional method. Melt-kneading can be performed using a kneader such as a single-screw extruder, a twin-screw extruder, a kneader or a Banbury mixer. The type of equipment used and the melt-kneading conditions are not particularly limited, but kneading is generally performed at 180 to 270 ° C. for 3 to 30 minutes.

In the composition of the present invention, styrene-isoprene, styrene-, which does not have a functional group at the terminal as the case requires.
Hydrogenated product of butadiene block copolymer, polystyrene,
Styrene-based resins such as ABS and other various thermoplastic resins, reinforcing agents such as glass fibers, fillers such as mica and talc, antioxidants, release agents, colorants, ultraviolet absorbers, antistatic agents, crystal nucleating agents, It may contain various additives such as flame retardants.

The composition of the present invention has the characteristic that it retains the characteristics inherently possessed by polycarbonate resins and that the impact resistance at low temperatures is improved without delamination. The polymer composition of the present invention can be molded by any molding method such as injection molding, extrusion molding, press molding, blow molding, extrusion blow molding, calender molding, cast molding, etc. It is possible to manufacture molded articles of any shape and application such as parts, machine parts, automobile parts, pipes, sheets, films and daily necessities.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Further, in the following Examples and Comparative Examples, each polymer is shown by an abbreviation, and the specific contents are shown in Tables 1 and 2 below.

[0023]

[Table 1] (Production of Block Copolymer Having Hydroxyl Group at Terminal) Production Example 1, After polymerization of styrene, isoprene and styrene in order using s-butyllithium as an initiator in cyclohexane and completion of the polymerization, 10 times the polymerization active terminal. By adding mol of ethylene oxide, a copolymer having a structure of S—I—S having a hydroxyl group at one end of the molecular chain was obtained. Further, by hydrogenating this, SEPS having a terminal hydroxyl group
-OH (I) was obtained. Further, SEPS-OH (II) was obtained by changing the amount of the monomer used. The molecular properties are shown in Table 2.

Production Example 3. Using butadiene instead of isoprene in Production Example 1 and using SEBS-OH (III
) Got.

Production Example 4. After completion of the polymerization, a block copolymer having no terminal functional group, SEPS (II), was obtained in the same manner as in Production Example 1 without adding ethylene oxide.

[0026]

[Table 2] (Examples 1 to 6 and Comparative Examples 1 to 3) Each polymer shown in Table 1 and Table 2 was blended at a temperature of 250 ° C. by a twin-screw extruder at a weight ratio shown in Table 3 below to prepare a blend. Using the obtained compound, a test piece was prepared by injection molding at 270 ° C.
Bending strength according to 7113, normal temperature by Izod,
The impact resistance at 20 ° C was measured. The state of delamination was determined by visually observing the cross section of the test piece.

As a result, the results shown in Table 3 below were obtained.

[0028]

[Table 3] From the results in Table 3 above, it can be seen that the composition according to the present invention has improved low temperature impact resistance.

[0029]

When the resin composition of the present invention is used, the impact resistance of the polycarbonate resin at low temperatures can be improved without delamination.

Front page continuation (72) Inventor Issei Ishiura 41 Miyukigaoka, Tsukuba City, Ibaraki Prefecture Kuraray Co., Ltd.

Claims (1)

[Claims] 1. (a) Polycarbonate resin 95 to 3
At least 0 part by weight, and (b) at least one selected from the group consisting of a polymer block mainly composed of an aromatic vinyl compound and a hydrogenated polybutadiene block obtained by hydrogenating a polybutadiene having a 1,2-bond content of 20% or less. One block A, hydrogenated polyisoprene block, hydrogenated polybutadiene block obtained by hydrogenating polybutadiene having a 1,2-bond content of 30 to 70%, and hydrogenated isoprene-butadiene random Modified block copolymer (b-1) having a hydroxyl group at the terminal of a block copolymer containing at least one block B selected from the group consisting of copolymer blocks and /
Alternatively, a modified block copolymer (b-2) having a hydroxyl group at the terminal of a block copolymer containing at least one polymer block C mainly containing an aromatic vinyl compound and at least one polyisobutylene block D 5-70
A thermoplastic resin composition comprising 1 part by weight.