JP2556376B2 - Polycarbonate and polystyrene composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition containing an aromatic polycarbonate and a styrene-based polymer, which improves the compatibility of both resins and is caused by a low compatibility in a molded article. Provided is a resin composition in which the delamination and the reduction in impact strength are remarkably reduced as compared with the prior art.

[Prior Art and Problems] Blending of a styrene resin for the purpose of improving the melt fluidity of an aromatic polycarbonate has been conventionally performed (for example, Japanese Patent Publication Nos. 43-6295 and 44-11551). . However, since the polycarbonate and the styrene resin are essentially incompatible with each other, delamination occurs due to the shearing force at the time of molding, impact strength is lowered, and good physical properties cannot be obtained.

In order to improve the compatibility, there is an example in which an organic low molecular compound such as a phosphoric acid ester or a phthalic acid ester is added (Japanese Patent Publication No. 44-11551), but the compatibility is improved to some extent. , I can't say it's enough yet.

Further, when the addition amount of the styrene-based resin is increased, the layered peeling becomes apparent and the impact resistance is significantly deteriorated, so that the addition amount of the styrene-based resin is also limited.

A method for producing a crosslinked resin by reacting an aromatic polycarbonate with an oxazoline derivative in the presence of a catalyst is known (Japanese Patent Laid-Open No. 63-248852).

[Means for Solving the Problems] The present inventor remarkably improved the compatibility between the aromatic polycarbonate and polystyrene by making the ratio of the terminal groups of the aromatic polycarbonate different from the conventional one, and the resin It has been found that the melt flowability of the molded article made from the composition can be improved in the same manner as in the past, while remarkably reducing delamination and reduction in impact strength.

That is, the present invention provides 50 to 90% by weight of an aromatic polycarbonate and 50 to 3 copolymers of a styrene-based monomer and an unsaturated monomer having an epoxy group or an oxazolinyl group.
In the resin composition containing 10 wt%, the ratio (I) :( II) of the phenolic end group represented by the following formula (I) and the non-phenolic end group represented by the following formula (II) as the aromatic polycarbonate is A resin composition comprising an aromatic polycarbonate of 1:19 to 1: 0.

(In the above formula, R ₁ and R ₂ may be the same or different from each other, and each is a hydrogen atom or an alkyl group having 20 or less carbon atoms, which may be halogen-substituted).

The terminal group ratio of the aromatic polycarbonate can be easily adjusted by preparing the aromatic polycarbonate by the transesterification method and changing the molar ratio of the starting material diphenyl carbonate and diphenol (for example, bisphenol A). In the present invention, the aromatic polycarbonate has the formula (Each R is phenylene, halogen-substituted phenylene or C ₁ ~
C ₂₀ alkyl-substituted phenylene, A and B each represent a hydrogen atom, a C ₁ -C ₁₂ hydrocarbon group containing no aliphatic unsaturation, or a group forming a cycloalkane group with an adjacent carbon atom). Mainly has. For example, when bisphenol A and diphenyl carbonate are transesterified, the terminal of the polycarbonate is a phenolic residue derived from bisphenol A or a phenyl group derived from diphenyl carbonate. Therefore, when the molar ratio of bisphenol A is increased during the transesterification reaction, the ratio of phenolic end groups in the produced polycarbonate increases. The aromatic polycarbonate may be branched. Such branched polycarbonates are obtained as branched thermoplastic random branched polycarbonates by reacting polyfunctional aromatic compounds with diphenol and / or carbonate precursors.

Aromatic polycarbonate that has been commonly used in the past
Particularly in aromatic polycarbonates made by the phosgene method, the ratio of phenolic end groups to non-phenolic end groups is less than 1:20. That is, bisphenol A
Polycarbonate is produced by reacting phosgene with phosgene. By adding a small amount of phenol in the raw material or during the reaction, the polymer end is blocked with phenol (hydroxyl group reacts).

According to the invention, the ratio (I) :( II) of the phenolic end groups of the aromatic polycarbonate is 1:19 to 1: 0, preferably
1:10 to 1: 0, especially 1: 5 to 1: 0.

The OH group concentration of the phenolic end group is determined by measuring the absorption intensity of FTIR at 3600 cm ^-1 . The total terminal group concentration is calculated by determining the average molecular weight based on the IV (intrinsic viscosity) value measured with a methylene chloride solution.
The Schnell equation was used when converting the IV value to the average molecular weight.

IV = 1.23 × 10 ⁻⁴ M ^0.83 (M = viscosity average molecular weight) Examples of the unsaturated monomer having an epoxy group or an oxazolinyl group used in the present invention include the following. Preferred epoxy group-containing unsaturated monomers include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, hydroxyalkyl (meth) acrylate glycidyl ether, polyalkylene glycol (meth) acrylate glycidyl ether, and glycidyl itaconate. As a preferred oxazolinyl group-containing unsaturated monomer,
General formula And Z includes a polymerizable double bond. Preferred substituents Z are:

In these formulas, R ² is a hydrogen atom or an alkyl group or an alkoxy group having 1 to 6 carbon atoms, for example, a methyl group,
i- and n-propyl groups or butyl groups.

Particularly preferred compounds have the general formula In the vinyl oxazoline represented by, R ² has the above meaning and is preferably a hydrogen atom or a methyl group.

The epoxy group- or oxazolinyl group-containing unsaturated monomer is copolymerized with the styrene-based monomer to form a copolymer of the styrene-based monomer used in the present invention and the epoxy group- or oxazolinyl-group-containing unsaturated monomer.

In the styrene-based copolymer used in the present invention, the amount of the unsaturated monomer-containing unit having an epoxy group or an oxazolinyl group is preferably 0.1 to 30% by weight based on the copolymer.

In the present invention, the amount ratio of the aromatic polycarbonate and the styrene copolymer is 50 to 97% by weight and 50 to 3% by weight, respectively, and preferably 60 to 90% by weight and 40 to 10% by weight, respectively. If the amount of aromatic polycarbonate is less than 50% by weight, its peculiar properties, particularly mechanical properties and heat resistance, will not be exhibited. On the other hand, if the amount of aromatic polycarbonate is more than 97% by weight and the amount of styrene-based polymer is less than 3% by weight, melt flowability will be insufficient.

Further, the resin composition of the present invention, as long as the physical properties are not impaired, other resins and additives such as pigments, dyes, reinforcing agents, fillers, heat-resistant agents, oxidative deterioration inhibitors, and weather resistance during resin mixing and molding. Agents, lubricants, release agents, crystal nucleating agents, plasticizers, fluidity improvers, antistatic agents and the like can be added.

Reinforcing fillers include finely divided aluminum, iron or nickel, metal oxides and non-metals such as carbon filaments, silicates such as mica, aluminum silicate (clay), talc, asbestos, titanium dioxide, wollastonite, novaculite, It can be selected from potassium titanate and titanate whiskers, glass flakes, glass beads and glass fibers and polymer fibers, or a combination thereof.

The reinforcing filler may be used in an amount capable of exerting a reinforcing action, and is usually 1 to 60% by weight based on the total weight of the composition.
The preferred range is 5 to 50% by weight. The preferred toughening agent is glass, for example glass filaments, or mixtures of glass and talc, glass and mica, glass and aluminum silicate are preferably used. The plastic reinforcing filaments are preferably made by mechanical pulling. The gas filament diameter is preferably about 0.00012 to 0.00075 inches, although this is not essential to the invention.

If the composition of the invention comprises a polycarbonate consisting of brominated bisphenols, further inorganic or organic antimony compounds may be incorporated into the composition of the invention in order to synergistically increase the flame retardancy achieved thereby. Suitable inorganic antimony compounds antimony oxide (Sb ₂ O _3); encompasses the like; phosphoric acid _{antimony; KSb (OH) 6; NH} 4 SbF 6; SbS 3.
A wide variety of organic antimony compounds may also be used, such as antimony esters with organic acids, cyclic alkyl antimonites, aryl antimonate compounds and the like. Examples of representative organic antimony compounds are KSb tartrate, Sb capronate, Sb (OCH ₂ CH ₃ ); Sb [OCH (CH ₃ ) CH ₂ CH ₃ ] ₃ ; Sb
Including polymethylene glycolate, triphenyl antimony and the like. If an antimony compound is used, the preferred antimony compound is antimony oxide.

As the stabilizer and the antioxidant, hindered phenol, phosphite, metal salt of phosphoric acid, metal salt of phosphorous acid and the like can be mixed.

In producing the resin composition of the present invention, the respective components can be mixed by a conventionally known method. For example,
A method in which the respective components are dispersed and mixed in a turnable mixer, a Henschel mixer, a ribbon blender, a high speed mixer typified by a super mixer, and then melt-kneaded by an extruder, a Banbury mixer, a roll or the like is appropriately selected.

[Examples] In the following examples, "parts" are parts by weight.

The aromatic polycarbonates according to the invention used in the examples are diphenyl carbonate and bisphenol A.
Was obtained by transesterification with methylene chloride, the intrinsic viscosity measured at 25 ° C. was 0.50 dl / g, and the ratio of phenolic end groups to non-phenolic end groups was about 3: 7 and
It was 1: 1. These are designated as PC (30) and PC (50), respectively.

For comparison, an aromatic polycarbonate obtained by polymerizing bisphenol A by the phosgene method and end-capping it with a phenyl group to give a ratio of phenolic end groups of about 1:99 (intrinsic viscosity at 25 ° C in methylene chloride 0.5 dl / g) was used. P this
Represented as C (1).

5% by weight as oxazolinyl group-containing polystyrene
Oxazoline-based monomer-containing polystyrene (Nippon Shokubai Chemical Co., Ltd., CX-RPS-1005) was used. As the epoxy group-containing polystyrene, polystyrene containing 5% by weight of glycidyl methacrylate (manufactured by NOF CORPORATION, CP
1005S) was used. G as a polystyrene for comparison
PPS CR3500 (Dainippon Ink and Chemicals, Inc.) was used.

The components in the proportions (weight ratios) shown in Table 1 were melted and kneaded at a kneading set temperature of 280 ° C. with a 65 mm single screw extruder to form pellets. The melt index (MI) was measured using the pellets, and the test pieces were molded to measure the physical properties. The measurement conditions are as follows, and the results are also shown in Table 1.

Melt index: 2mm diameter orifice is used and load
It was measured at 1.2 kg and a temperature of 300 ° C.

Delamination: A 1 / 16-inch flam bar was bent and examined for the presence or absence of delamination.

1/8 ″ Izod impact strength (notch): According to ASTM D256.

As can be seen from the table, Comparative Example 1 containing no polystyrene
In, the melt fluidity (melt index) is poor.
When polystyrene is contained (Comparative Examples 3 to 5), the melt fluidity is improved, but the impact strength is significantly reduced. In Examples 1 to 4 according to the present invention, the melt fluidity is improved to the same level as the corresponding Comparative Examples 3 to 5, while the reduction in impact strength is remarkably reduced. Further, even if a large amount of styrene resin is used (Example 4), delamination does not occur.

Claims (1)

(57) [Claims] An aromatic polycarbonate (50 to 90% by weight) and a copolymer of a styrene-based monomer and an unsaturated monomer having an epoxy group or an oxazolinyl group (50 to 3% by weight).
In the resin composition containing, the ratio (I) :( II) of the phenolic end group represented by the following formula (I) and the non-phenolic end group represented by the following formula (II) as the aromatic polycarbonate is 1: A resin composition comprising an aromatic polycarbonate of 19 to 1: 0. (In the above formula, R ₁ and R ₂ may be the same or different from each other, and each is a hydrogen atom or an alkyl group having 20 or less carbon atoms, which may be halogen-substituted).