KR20210067104A - Flame retardant polycarbonate and copolyester alloy resin composition with improved transparency and chemical resistance - Google Patents

Abstract

The present invention relates to a polycarbonate and copolyester alloy resin composition which shows flame resistance and has improved transparency, chemical resistance, heat resistance and impact resistance. The polycarbonate and copolyester alloy resin composition includes: (A) 60-95 wt% of polycarbonate; (B) 5-40 wt% of copolyester containing a dicarboxylic acid ingredient and a diol ingredient; and (C) 5-30 parts by weight of a solid-phase polymer flame retardant based on 100 parts by weight of the total weight of ingredients (A) and (B), wherein the dicarboxylic acid ingredient contains a terephthalic acid residue, the diol ingredient contains a 1,3-cyclohexanedimethanol residue or a terephthalic acid residue and a 2,2,4,4-tetramethyl-1,3-cyclobutanediol residue.

Description

Flame retardant polycarbonate and copolyester alloy resin composition with improved transparency and chemical resistance

The present invention relates to a polycarbonate and copolyester alloy resin composition, and more particularly, to a flame-retardant polycarbonate and copolyester alloy resin composition with improved transparency and chemical resistance.

Polycarbonate is used for various purposes such as housing materials for electronic products due to excellent characteristics such as impact resistance and heat resistance. However, there is a problem in that the appearance color is changed or cracks occur and the quality of the product is induced by women's cosmetics and fragrances commonly used in the market.

Since polyester has excellent chemical resistance and mechanical strength, its use is increasing in the field of building interior materials or molded signboards. However, polyester has a low heat resistance compared to polycarbonate-based materials, and thus physical properties deterioration and deformation occur due to changes in the surrounding environment, so that it is unsuitable for use alone as a housing material for electronic products.

Various attempts have been made to solve such problems of polycarbonate or polyester, and research on a method for blending polycarbonate and polyester has been continued.

On the other hand, there are cases of adding Si-PC (Siloxane Polycarbonate Copolymer) or mixing copolyesters with different molecular structures to improve chemical resistance while maintaining transparency to existing polycarbonates. , a technology for improving heat resistance and impact resistance has not been suggested.

Korean Patent Laid-Open No. 2016-0075207 uses polyester resin and polycarbonate resin for the purpose of improving chemical resistance and mechanical properties for use as a housing material for electronic products, and uses a phosphorus-based flame retardant to further reinforce flame retardancy. It discloses a technology that secures a flame retardancy of 0 (@ 3.0 mm), but it is an opaque resin that shows insufficient flame retardancy for use in the housing of electronic products, and does not mention the improvement of transparency and chemical resistance while flame retardancy is given. is not

Korean Patent Application Laid-Open No. 2013-0044867 refers to the improvement of thermal stability, color stability, and flame retardancy as a polyester/polycarbonate blend, but does not mention improvement of physical properties of impact resistance and chemical resistance along with flame retardancy.

An object of the present invention is to provide a polycarbonate and copolyester alloy resin composition with improved transparency and chemical resistance, heat resistance and impact resistance while imparting flame retardancy.

The present invention in order to solve the above problems, (A) 60 to 95% by weight of polycarbonate; (B) 5 to 40% by weight of a copolyester comprising a dicarboxylic acid component and a diol component; and (C) 5 to 30 parts by weight of a solid polymer flame retardant based on a total of 100 parts by weight of the components (A) and (B), wherein the dicarboxylic acid component includes a terephthalic acid residue, and the diol component comprises: Polycarbonate and copolyester alloys comprising 1,3-cyclohexanedimethanol residues or 1,4-cyclohexanedimethanol residues and 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues A resin composition is provided.

In addition, the copolyester provides a polycarbonate and copolyester alloy resin composition comprising a repeating unit represented by the following formula (1).

[Formula 1]

In Formula 1, n and m are each independently an integer of 1 to 10.

In addition, the copolyester provides a polycarbonate and copolyester alloy resin composition, characterized in that the glass transition temperature is 100 ℃ or more.

In addition, the solid polymer flame retardant provides a polycarbonate and copolyester alloy resin composition comprising a repeating unit represented by the following formula (2).

[Formula 2]

In Formula 2, X is an alkylene group having 1 to 10 carbon atoms, a is an integer of 6 to 20, and b is an integer of 1 to 20.

In addition, the solid polymer flame retardant has a weight average molecular weight (Mw) of 1,000 to 100,000 g / mol, and provides a polycarbonate and copolyester alloy resin composition, characterized in that the glass transition temperature is 80 to 130 ℃ .

According to the present invention, polycarbonate and copolyester alloy with improved heat resistance and impact resistance as well as transparency and chemical resistance while imparting flame retardancy by using a solid polymer flame retardant while alloying a copolyester of a specific composition to polycarbonate A resin composition can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

The present inventors have tried to improve the physical properties that are lacking when used alone by blending polycarbonate and polyester in the prior art, but a resin composition with improved heat resistance and impact resistance as well as transparency and chemical resistance while imparting flame retardancy is not presented. As a result of repeated research while facing the current situation, when a solid polymer flame retardant is used while alloying a polycarbonate with a copolyester of a specific composition, flame retardancy is imparted, transparency and chemical resistance, as well as heat resistance and impact resistance can be improved. found and led to the present invention.

Accordingly, the present invention provides: (A) 60 to 95% by weight of polycarbonate; (B) 5 to 40% by weight of a copolyester comprising a dicarboxylic acid component and a diol component; and (C) 5 to 30 parts by weight of a solid polymer flame retardant based on a total of 100 parts by weight of the components (A) and (B), wherein the dicarboxylic acid component includes a terephthalic acid residue, and the diol component comprises: Polycarbonate and copolyester alloys comprising 1,3-cyclohexanedimethanol residues or 1,4-cyclohexanedimethanol residues and 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues Disclosed is a resin composition.

Hereinafter, each component of the polycarbonate and copolyester alloy resin composition according to the present invention will be described in more detail.

(A) polycarbonate

Polycarbonate (PC) used in the present invention has excellent impact resistance, heat resistance, weather resistance, self-extinguishing properties, flexibility, processability and transparency, excellent weather resistance, maintaining high physical properties for a long period of time, excellent heat resistance and cold resistance, severe temperature change still maintain performance.

The polycarbonate is a polymer of bisphenol A and may have a weight average molecular weight (Mw) of 10,000 to 200,000. In addition, branched chain ones may be used, preferably by adding 0.05 to 2 mol% of a tri- or more polyfunctional compound, for example, a compound having a trivalent or more phenolic group, based on the total amount of diphenol used for polymerization. Manufactured polycarbonate may be used.

In addition, the polycarbonate may have a melt index (300° C., 1.2 kg load) of preferably 3 to 28 g/10min, more preferably 5 to 20 g/10min. If the melt index of the polycarbonate is less than 3 g / 10 min, the processing temperature may be increased, so there may be difficulties in molding, and if it exceeds 28 g / 10 min, the strength may be weakened.

The polycarbonate used in the present invention may be prepared according to a conventionally used method, for example, by reacting dihydroxy phenol and phosgen in the presence of a molecular weight regulator and a catalyst, or , it can be prepared using an ester interchange reaction of a precursor obtained by dihydroxy phenol and diphenyl carbonate.

In the present invention, polycarbonate is included in an amount of 60 to 95% by weight, preferably 75 to 95% by weight, more preferably 85 to 95% by weight in consideration of the specific amount of copolyester and solid polymer flame retardant to be described later. % content may be included.

(B) copolyester

The copolyester used in the present invention is a polymer prepared by ester or transesterification and polycondensation reaction of a dicarboxylic acid component and a diol component, and is an amorphous copolyester in which a crystal structure is not formed in the molecular structure.

In the present invention, the copolyester is a resin in which a part of the diol component is modified in the dicarboxylic acid component. Specifically, a part of the diol component is 1,3-cyclohexanedimethanol or 1,4-cyclohexane. It is a copolyester modified with dimethanol and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

As the dicarboxylic acid component, terephthalic acid, which is an aromatic dicarboxylic acid, or dimethyl terephthalate, which is an aromatic dicarboxylate, may be used alone or in combination.

Accordingly, in the present invention, in the copolyester, the dicarboxylic acid component includes a terephthalic acid residue, and the diol component includes a 1,3-cyclohexanedimethanol residue or 1,4-cyclohexanedimethanol residue, 2, It contains 2,4,4-tetramethyl-1,3-cyclobutanediol residue, and may preferably include a repeating unit represented by the following Chemical Formula 1 in terms of improving transparency, heat resistance and flame retardancy as well as improving chemical resistance. .

[Formula 1]

In Formula 1, n and m are each independently an integer of 1 to 10.

In the present invention, the copolyester preferably has a glass transition temperature of 100° C. or higher, and more preferably 100 to 110° C. may be used. When the glass transition temperature of the copolyester is less than 100 ℃, the heat resistance and impact resistance of the final resin composition may be reduced.

In the present invention, the copolyester is included in an amount of 5 to 40% by weight, preferably 5 to 25% by weight, more preferably 5 to 15% by weight. When the content of the copolyester is less than 5% by weight, the chemical resistance is reduced, and when it exceeds 40% by weight, transparency, heat resistance and flame retardancy are deteriorated.

(C) Solid polymer flame retardant

In the present invention, as a flame retardant of a specific composition in the polycarbonate and copolyester, flame retardancy is imparted by containing a solid polymer flame retardant, and heat resistance and impact resistance are improved as well as transparency and chemical resistance. When using the existing liquid flame retardant, all physical properties such as transparency, chemical resistance, heat resistance and impact resistance are lowered compared to the case of using a solid polymer flame retardant.

As the solid polymer flame retardant, polyphosphonate including a repeating unit represented by the following Chemical Formula 2 may be used as a phosphorus-based flame retardant.

[Formula 2]

In Formula 2, X is an alkylene group having 1 to 10 carbon atoms, a is an integer of 6 to 20, and b is an integer of 1 to 20

Specifically, the phosphorus-based flame retardant may have a weight average molecular weight (Mw) of 1,000 to 100,000 g/mol, preferably 10,000 to 50,000 g/mol. When the weight average molecular weight of the phosphorus-based flame retardant is less than 1,000 g/mol, flame retardancy and mechanical properties of the resin composition may be reduced, and if it exceeds 100,000 g/mol, fluidity and processability of the resin composition may be reduced.

In the present invention, the phosphorus-based flame retardant preferably has a glass transition temperature of 80 to 130° C., and more preferably 90 to 110° C. may be used. In the glass transition temperature range of the above range, the resin composition has excellent flame retardancy and transparency, and color (yellowing index) characteristics may be improved.

In the present invention, the solid polymer flame retardant is included in 5 to 30 parts by weight, preferably 10 to 25 parts by weight, more preferably 12 to 18 parts by weight, based on 100 parts by weight of the components (A) and (B). It may be included as a minor content. When the content of the solid polymer flame retardant is less than 5 parts by weight, the flame retardant performance is lowered, and when it exceeds 30 parts by weight, the impact strength and heat resistance are lowered.

The polycarbonate and copolyester alloy resin composition according to the present invention may further include inorganic fillers and functional additives suitable for the intended use or effect in addition to the above-mentioned main components. For example, anti-drip agents, light stabilizers, lubricants, toners, lubricants, UV stabilizers, antioxidants, coupling enhancers, heat stabilizers, plasticizers, impact modifiers, etc. can be additionally added to apply various uses.

Preparation of the polycarbonate and copolyester alloy resin composition according to the present invention is not particularly limited, and a method commonly used for preparing a mixed resin composition and the like may be used. For example, a polycarbonate and copolyester alloy resin composition may be prepared by quantifying and mixing other additives in the above-mentioned components (A) to (C) and then extruding using an extruder.

The polycarbonate and copolyester alloy resin composition according to the present invention has an effect of improving heat resistance and impact resistance as well as transparency and chemical resistance while imparting flame retardancy, and specifically, light transmittance (ASTM D1003, 3 mm thickness) standard) is 70% or more, preferably 75% or more, and the IZOD impact strength (ASTM D256, 1/8” thickness basis) is 5 kgf cm/cm or more, preferably 6 kgf cm/cm or more, The flame retardancy (UL94V, 1/8” thickness basis) is V-1 or higher, and the heat deflection temperature (HDT) (ASTM D648, 18.6 kg load, 6.4 mm thickness) is 100°C or higher, preferably 110°C or higher, , A characteristic in which the number of cracks observed is three or less according to the following chemical resistance evaluation method can be implemented.

[Chemical resistance evaluation method]

A chemical resistance test jig was prepared with a critical strain of 1.0%, the tensile specimen of the resin composition (ASTM D638 Type 1) was fixed with the test jig, and thinner (Xylene 40 wt% and Toluene 60 wt%) was applied to the tensile specimen for 1 minute. Then, after leaving it for 24 hours under the conditions of 23±2℃ and 50±5% relative humidity, the presence or absence of cracks in the specimen was visually observed.

On the other hand, the polycarbonate and copolyester alloy resin composition according to the present invention can be applied to the manufacture of various molded articles, and preferably has excellent impact resistance, heat resistance, transparency and chemical resistance, so that the transparent sheet for partitions and the appearance of electrical and electronic products It can be applied to parts.

Hereinafter, specific examples and comparative examples according to the present invention will be described.

First, the specifications of the components used in Examples and Comparative Examples of the present invention are as follows.

(A) Polycarbonate (PC)

A bisphenol A-type polycarbonate (Hopelex PC-1070, Lotte Chemical) having a melt index (300° C., 1.2 kgf) of 7 g/10 min was used.

(B) copolyester

(B-1) an amorphous copolyester having a glass transition temperature of 108° C. (TRITAN 1001, Eastman Corporation) of the structure of Formula 1, and (B-2) an amorphous copolyester having a glass transition temperature of 80° C. (PCTG) , JN100, SK Chemicals) was used.

(C) Solid polymer flame retardant

(C-1) Polyphosphonate (HM-1100, FRX) having a weight average molecular weight (measured by gel permeation chromatography (GPC)) of 15,000 g/mol and a glass transition temperature (Tg) of 100°C as a solid polymer type phosphorus flame retardant polymers) and (C-2) liquid type, single-molecular-weight phosphorus-based flame retardant, Bisphenol A diphosphate (CR-741, Daihachi) were used.

(D) anti-drip agent

Polytetrafluoroethylene (PTFE) (TSAN) (FS-200, Hannanoech) encapsulated with a polymer (SAN) of styrene and acrylonitrile was used.

Examples and Comparative Examples

After making the thermoplastic resin composition into a chip state using a twin-screw extruder heated to 200 to 250 ° C with the component composition shown in Table 1 below, and then drying at 80 ° C. for 4 hours using a hot air dryer, each specimen was prepared using a mold for specimen production. Injection molded. Meanwhile, it is preferable to minimize the residence time in order to prevent thermal decomposition of the resin composition during melt-kneading of the thermoplastic resin composition.

test example

Transparency, impact strength, flame retardancy, heat deformation temperature and chemical resistance were measured and evaluated for the prepared specimen according to the following method, and the results are shown in Table 1 below.

[Measurement and evaluation method]

(1) Transparency

Light transmittance (Total Transmittance) was measured for a specimen (3 mm thick) prepared according to ASTM D1003.

(2) Impact strength

The IZOD impact strength (1/8” thickness) of the specimens manufactured according to ASTM D256, the American standard measuring method for measuring the IZOD impact strength of plastics, was measured using a weight of a certain weight.

(3) flame retardancy

In accordance with UL94V flame retardancy regulations, the flame retardancy was measured at a thickness of 1/8”.

(4) Heat Deflection Temperature (HDT)

The heat deflection temperature was measured under a load of 18.6 kg for a specimen (6.4 mm thick) prepared according to ASTM D648, an American standard measuring method for measuring the heat resistance properties of plastics.

(5) chemical resistance

The condition of the injected tensile strength specimen was controlled for 24 hours under conditions of 23±2° C. and 50±5% relative humidity, and evaluation was performed according to the following method.

① A chemical resistance test jig was manufactured with a critical strain of 1.0% and the tensile specimen was fixed with the test jig.

② Thinner (Xylene 40% by weight and Toluene 60% by weight) was applied to the tensile specimen for 1 minute and then left at 23±2℃ for 24 hours.

③ After standing for 24 hours, the presence or absence of cracks in the specimen was visually observed.

<Evaluation criteria>

○: If there are no cracks in the tensile specimen, or if the number of cracks is less than 3 but not broken

△: When there are 4 or more cracks in the tensile specimen, but it is not broken

X: When the tensile specimen is in a broken state

Referring to Table 1, when a solid polymer flame retardant is used while alloying a copolyester of a specific composition to a polycarbonate according to the present invention (Examples 1 and 2), flame retardancy is imparted, transparency and chemical resistance, as well as heat resistance And it can be confirmed that excellent physical properties up to impact resistance are implemented.

On the other hand, it can be seen that when the copolyester of a specific composition is included in excess (Comparative Example 1), transparency and flame retardancy are significantly reduced, and when not included (Comparative Example 2), chemical resistance is significantly reduced.

In addition, when the phosphorus-based flame retardant in liquid form rather than solid polymer form is prescribed (Comparative Examples 3 and 7), transparency, impact resistance, heat resistance and chemical resistance are all lowered, and other than the copolyester specified in the present invention When copolyester (PCTG) is alloyed (Comparative Examples 4 to 6), it can be seen that chemical resistance is lowered, flame retardancy or transparency is lowered depending on the content thereof.

On the other hand, in using the solid polymer flame retardant according to the present invention, flame retardancy, impact resistance and heat resistance are more improved in a certain content range (compared to Examples 2 to 4), and transparency depending on whether an anti-drip agent is added or not And from the fact that the impact resistance is more improved (compared to Examples 3 and 5), the specific components are employed for the balance of physical properties such as heat resistance and impact resistance along with flame retardancy, transparency and chemical resistance, but in the component combination and composition ratio It is found advantageous to ensure that the preferred compositions set forth in the invention are satisfied.

The preferred embodiment of the present invention has been described in detail above. The description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains will understand that other specific forms can be easily modified without changing the technical spirit or essential features of the present invention.

Therefore, the scope of the present invention is indicated by the claims to be described later rather than the above detailed description, and all changes or modifications derived from the meaning, scope, and equivalent concept of the claims are included in the scope of the present invention. should be interpreted

Claims (5)

(A) 60 to 95% by weight of polycarbonate;
(B) 5 to 40% by weight of a copolyester comprising a dicarboxylic acid component and a diol component; and
(C) 5 to 30 parts by weight of a solid polymer flame retardant based on 100 parts by weight of the components (A) and (B);
including,
The dicarboxylic acid component includes a terephthalic acid residue, and the diol component includes a 1,3-cyclohexanedimethanol residue or 1,4-cyclohexanedimethanol residue, 2,2,4,4-tetramethyl-1, A polycarbonate and copolyester alloy resin composition comprising a 3-cyclobutanediol moiety. According to claim 1,
The copolyester is a polycarbonate and copolyester alloy resin composition comprising a repeating unit represented by the following formula (1):
[Formula 1]

In Formula 1, n and m are each independently an integer of 1 to 10. According to claim 1,
The copolyester is a polycarbonate and copolyester alloy resin composition, characterized in that the glass transition temperature is 100 ℃ or more. According to claim 1,
The solid polymer flame retardant polycarbonate and copolyester alloy resin composition comprising a repeating unit represented by the following formula (2):
[Formula 2]

In Formula 2, X is an alkylene group having 1 to 10 carbon atoms, a is an integer of 6 to 20, and b is an integer of 1 to 20. 5. The method of claim 4,
Polycarbonate and copolyester alloy resin composition, characterized in that the solid polymer flame retardant has a weight average molecular weight (Mw) of 1,000 to 100,000 g / mol, and a glass transition temperature of 80 to 130 ℃.