WO2019124928A1 - Flame-retardant polyethylene terephthalate resin composition having improved impact resistance, and manufacturing method therefor - Google Patents

Abstract

Disclosed are a flame-retardant agent composition for PET that has improved impact resistance and is used in electric and electronic products and components, and a manufacturing method therefor. The present invention comprises a flame-retardant polyethylene terephthalate resin composition which comprises a polyethylene terephthalate resin and a flame-retardant agent, wherein the amount of the flame-retardant agent with respect to 100 parts by weight of the polyethylene terephthalate resin is 15 to 45 parts by weight, the flame-retardant agent is produced by melt mixing polyester with brominated polystyrene in advance, and the polyester is contained in an amount of 2 to 10 parts by weight with respect to 100 parts by weight of the flame-retardant agent.

Description

Flame retardant polyethylene terephthalate resin composition with improved impact resistance and method for manufacturing the same

The present invention relates to a flame retardant polyethylene terephthalate resin composition having improved impact resistance and a method of manufacturing the flame retardant polyethylene terephthalate resin composition. More particularly, the present invention relates to a flame retardant polyethylene terephthalate resin composition having improved impact resistance for electrical and electronic products and a method for producing the same.

Thermoplastic resins are produced in large quantities because they are lightweight, strong in strength, excellent in water resistance, chemical resistance and electrical insulation, and easy to be molded thereon. BACKGROUND OF THE INVENTION Polyalkylene terephthalates, especially polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), are thermoplastic polyester resins having excellent electrical properties widely used as insulators for wrapping electric wires and other electronic components.

Among them, polyethylene terephthalate has been extensively used in many fields such as clothing, interior, padding, nonwoven fabric and industrial materials due to excellent mechanical properties and easy processability. However, since polyethylene terephthalate is flammable, various additives and methods for imparting flame retardancy to conventionally-used flame retardants have been studied for application to various uses as described above.

Generally, a flame retardant using a styrene-based resin has good processability and mechanical strength and is used mainly as a casing for electrical and electronic products. However, the styrene-based resin itself has no resistance to flame, and when the flame is ignited by an external ignition factor, the resin acts as energy that helps combustion, and continuously diffuses the fire.

Most commercialized flame retardant resins are prepared by the addition type flame retarding method in which a flame retardant containing halogen or phosphorus, which is an inert element, is added during compounding, and an addition type flame retardant method in which a flame retardant is added to impart styrene- It is prepared by adding one or more components selected from a halogen-containing organic compound and an antimony-containing inorganic compound to the resin. Among these, various brominated aromatic compounds are known flame retardants for thermoplastic resins. Brominated polystyrene is accepted as a commercially important flame retardant for use in various thermoplastic resins. However, the flame retardancy is very good, but the overall physical properties are seriously degraded. Further, there is a problem that thermal stability is lowered. Therefore, in the production of the flame retardant resin, it is very important to maintain the excellent flame retardancy while minimizing the physical properties and incidental effects.

Accordingly, an object of the present invention is to provide a flame retardant polyethylene terephthalate resin composition having improved impact strength as compared with a conventional reinforced flame retardant polyester composition, and a method for producing the same.

In order to achieve the above object, the present invention provides a resin composition comprising: a polyethylene terephthalate resin; And a flame retardant, wherein the content of the flame retardant relative to 100 parts by weight of the polyethylene terephthalate resin is 15 to 45 parts by weight, the flame retardant is prepared by preliminarily melting and mixing the brominated polystyrene and the polyester, Based on the weight of the flame-retardant polyethylene terephthalate resin composition.

The present invention also relates to a method for producing a flame retardant, comprising the steps of: preparing a flame retardant by previously melt-kneading brominated polystyrene and polyester; And melting and mixing the flame retardant and polyethylene terephthalate. The present invention also provides a method for producing a flame retardant polyethylene terephthalate resin.

The flame retardant polyethylene terephthalate resin composition having improved impact resistance according to the present invention and the method for producing the same can produce a resin for flame retardant polyethylene terephthalate having an improved impact strength.

Hereinafter, the present invention will be described in more detail. In the following, unless otherwise specified, the unit "%" means "% by weight".

The present invention relates to a flame retarded polyethylene terephthalate (PET) composition comprising polyethylene terephthalate (PET), a styrene-based flame retardant, a flame retardant aid, a filler and an additive.

The polyethylene terephthalate (PET) is a crystalline thermoplastic resin widely used for fibers, films, bottles and the like, and it is also used as engineering plastic (GF-PET) according to glass fiber. The reinforced engineering plastics have heat resistance, chemical resistance, electrical characteristics and weather resistance and are used in the fields of electric and electronic, automobile and vehicle. It has excellent heat resistance, strength and rigidity, and is free from stress cracks.

The polyethylene terephthalate has an intrinsic viscosity of 0.3 to 0.9 cm 3 / g, preferably an intrinsic viscosity of 0.4 to 0.8 cm 3 / g. If the intrinsic viscosity is less than 0.3 cm < 3 > / g, the mechanical strength such as tensile strength, bending strength and impact strength is low and there is a high possibility of breakage after molding. When the intrinsic viscosity exceeds 0.8 cm & Kneading with an additive such as a reinforcing agent and a flame retardant is difficult during extrusion, flowability at the time of injection is low, and problems such as non-molding may occur. The intrinsic viscosity was UFIT, UVS-basic equipment, and Ubbelohde, 1B type viscometer was used for viscosity. The test samples were dissolved in a solvent ortho-chlorophenol and measured according to the ISO 1628 test method.

The flame retardant is a halogenated styrene type flame retardant. The halogen includes fluorine (F), bromine (Br), chlorine (Cl), and iodine (I). In the case of the fluorine (F), the bonding force is so strong that it can not generate radicals. The iodine (I) is not suitable as a flame retardant used at high temperature because its bonding force is very weak and decomposes easily at low temperatures. Therefore, bromine (Br) and chlorine (Cl) are mainly used as flame retardants, and bromine flame retardants having excellent cost effectiveness are mainly used. Such a bromine-based flame retardant has a merit that a sufficient flame retardant effect can be obtained even when a very small amount of the flame retardant is added compared with an inorganic material, and thus it is widely used in electric and electronic products which require high impact strength.

Examples of the brominated flame retardant include brominated polystyrene, brominated polycarbonate, decabromodiphenyl oxide, decabromodiphenyl ethane, brominated epoxy, and compounds thereof. Brominated polystyrene is one of the polymer resins used for the purpose of improving the flame retardancy of polyester.

The flame retardant is 15 to 45 parts by weight, preferably 15 to 40 parts by weight, more preferably 20 to 35 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin. When the content of the flame retardant is less than 15 parts by weight, It may be difficult to achieve UL94 standard V-0 rating. If it exceeds 45 parts by weight, mechanical properties such as tensile strength, flexural strength and impact strength may be lowered. The bromine content of the polystyrene is 60 to 75%, preferably 64 to 70%. If the bromine content is less than 60%, the flame retardancy may be lowered and it may be difficult to achieve the UL94 standard V-0 rating. The higher the bromine content, the better the flame retardant content can be reduced. And the molecular weight of the brominated polystyrene is preferably 10,000 to 100,000.

Further, as the flame retardant used in the present invention, a flame retardant mixed with polystyrene bromide and polyester may be used. The polyester may be selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), glycol modified polyethylene terephthalate (PETG), glycol modified polycyclohexyl (PCTG), and compounds thereof, and is preferably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT). Since the melting points of polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT) as crystalline materials are 250, 225 and 230 ° C., respectively, the melting point of brominated polystyrene is 240 Lt; RTI ID = 0.0 > C, < / RTI > However, PTT has difficulty in supplying and supplying raw materials, and it is difficult to mix PTT because of high price.

The polyester mixed with the flame retardant is 2 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the flame retardant.

The flame retardant auxiliary agent has a role and function of improving the flame retardancy by assisting the bromine flame retardant agent in the flame retardant composition for polyethylene terephthalate (PET). The flame retardant aid may be selected from the group consisting of antimony compounds, antimony trioxide, sodium antimonite, and compounds thereof. The content of the flame-retardant auxiliary may be selected from the group consisting of polyethylene terephthalate resin Is 3 to 12 parts by weight, preferably 5 to 10 parts by weight, based on 100 parts by weight. If the content of the flame-retardant aid is less than 3 parts by weight, the flame retardancy may deteriorate and it may be difficult to achieve the UL94 standard V-0 rating. If the content is more than 12 parts by weight, the mechanical properties such as tensile strength, bending strength, .

The filler improves mechanical strength such as tensile elastic modulus, flexural modulus and the like and improves thermal stability in a flame retardant composition for PET. The filler is selected from the group consisting of glass fiber, wollastonite, calcium silicate, montmorillonite, layered silicate nanoclay, Mica, talc and compounds thereof, The content of the filler relative to 100 parts by weight of the polyethylene terephthalate resin is 20 parts by weight to 150 parts by weight, preferably 15 to 100 parts by weight. If the content of the filler is less than 20 parts by weight, the required mechanical strength may be insufficient and the required physical properties may be insufficient. If the filler content is more than 150 parts by weight, the kneadability during compounding may be insufficient, , Surface defects, and the like.

The flame retardant composition for PET may further include an additive. The additive may include a chain extender, an impact modifier, a nucleating agent, a crystallization promoter, a hydrolysis inhibitor Hydrolysis additives, Anti-oxidants, Carboxylic acid scavengers, Transesterification inhibitors, Gloss enhancers, Alloying agents, Processing agents a stabilizer, a lubricant, an anti-drip agent and a compound thereof. The content of the additive is preferably 3 parts by weight to 20 parts by weight per 100 parts by weight of polyethylene terephthalate, 5 to 15 parts by weight. If the amount of the additive is less than 3 parts by weight, the mechanical strength may be lowered due to oxidation due to oxidation during processing. If the additive is more than 20 parts by weight, The drop in strength, especially impact strength, can be reduced.

And a method for producing the PET flame retardant composition according to the present invention. First, the above flame retardant is a product obtained by previously mixing brominated polystyrene and polyester, or a mixture of brominated polystyrene and polyester is used. The polyester mixed with the flame retardant is preferably polyethylene terephthalate or polybutylene terephthalate in an amount of 2 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the flame retardant.

A flame retardant composition for PET can be prepared by a compounding process in which 3 to 15 kinds of raw materials including the polyethylene terephthalate, the brominated polystyrene and a polyester mixed with a flame retardant, a filler, a flame retardant aid and additives are put in an extruder and melt- have. As a result, the compatibility of the polyester resin (polyethylene terephthalate, PET) and the flame retardant was improved due to the increase of the dispersibility during the processing of the polyester, and the impact strength to the 3.2 mm test piece according to ASTM D256 was 70 J / m, and it was confirmed that the impact strength was improved by about 15 to 37% with respect to 100 parts by weight of the conventional composition for reinforced flame retardant PET.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

[Example 1] Production of flame retardant composition for PET

(Φ: 40 mm, L / D = 50 mm) heated to about 200 to 270 ° C. was placed in a flask equipped with a stirrer, a stirrer, a stirrer, a thermometer, 44), melted and kneaded to prepare pellets. At this time, flame retardant A is SAYTEX-621 of Albermale, and SAYTEX-621 is a product which melts and mixes about 2 to 10% of polyester in the production of flame retardant. The physical properties according to the examples are measured and reported in the following Table 1.

[Examples 2 to 5] Production of flame retardant composition for PET

Using the composition shown in the following Table 1, pellets were prepared by melting and kneading using a biaxial kneading extruder (Φ: 40 mm, L / D = 44) heated to about 200 to 270 ° C. in the same manner as in Example 1 . The physical properties according to the examples are measured and reported in the following Table 1.

[Example 6] Production of flame retardant composition for PET

The flame retardant granule was prepared by continuously charging 5.0 mol% of PBT and 95.0% of the flame retardant B into a biaxial kneading extruder (Φ: 40 mm, L / D = 44) heated to about 240 to 350 ° C., melting and kneading. Then, the same procedure as in Example 1 was repeated except that 48.8% of polyethylene terephthalate, 13.0% of flame retardant granules, 30% of glass fiber, 3.2% of flame retardant auxiliary, and 5% of additives were added to a twin-screw extruder 40 mm, L / D = 44) to prepare pellets. The 13.0% flame retardant granule is composed of 0.65% of PBT resin and 12.35% of flame retardant B, and the flame retardant B is a general brominated polystyrene flame retardant, FR-803P of Chempia. The physical properties according to the examples are measured and reported in the following Table 1.

[Example 7] Production of flame retardant composition for PET

As shown in the following Table 1, pellets were produced by melting and kneading in the same manner as in Example 6, except that 0.65% of PET was used instead of 0.65% of PBT. The physical properties according to the examples are measured and reported in the following Table 1.

division		Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Example 7
PET resin (unit:% by weight)		52.5	48.75	45.00	63.75	33.75	48.8	48.8
PBT resin (unit: wt%)		-	-	-	-	-	0.65	-
PET resin (unit:% by weight)		-	-	-	-	-	-	0.65
Glass fiber (unit: wt%)		30	30	30	15	45	30	30
Flame retardant A (unit: wt%)		10.0	13.0	16.0	13.0	13.0	-	-
Flame retardant B (unit: wt%)		-	-	-	-	-	12.35	12.35
Flame Retarding Adduct (Unit: wt%)		2.5	3.25	4.0	3.25	3.25	3.2	3.2
Other additives (% by weight)		5.0	5.0	5.0	5.0	5.0	5.0	5.0
Br content	%	6.46	8.40	10.34	8.40	8.40	8.46	8.46
Impact strength (J / m)	3.2 mm	75.2	73.8	72.2	73.4	77.0	73.6	74.8
	6.4 mm	56.5	54.9	53.6	53.9	57.7	55.4	56.3
The tensile strength	MPa	1420	1,390	1,380	1,120	1,716	1,380	1.407
Flexural strength	MPa	1,834	1,835	1,828	1,092	2,577	1,836	1,833
liquidity		14.7	14.6	4.8	15.4	9.9	14.8	13.2
Flammability		2.3	1.9	1.4	2.5	1.5	2.1	1.7

[Comparative Example 1] Production of flame retardant composition for PET

(Φ: 40 mm, L / D = 50 mm) heated to about 200 to 270 ° C. was placed in a vessel equipped with a stirrer, a stirrer, a stirrer, a thermometer, 44), melted and kneaded to prepare pellets. The physical properties according to comparative examples are measured and reported in Table 2 below.

[Comparative Examples 2 to 3] Production of flame retardant composition for PET

Using the composition shown in the following Table 2, pellets were produced by melting and kneading using a biaxial kneading extruder (Φ: 40 mm, L / D = 44) heated to about 200 to 270 ° C. in the same manner as in Comparative Example 1 . The physical properties according to comparative examples are measured and reported in Table 2 below.

[Comparative Example 4] Production of flame retardant composition for PET

The flame retardant auxiliary agent and the other additives were added in the same manner as in Comparative Example 1, in the same manner as in Comparative Example 1, except that the flame retardant agent was added in an amount of about 200 to 200% by weight, as in Comparative Example 1, 48.8% of polyethylene terephthalate (PET), 0.65% of polybutylene terephthalate (PBT) The mixture was melted and kneaded using a biaxial kneading extruder (?: 40 mm, L / D = 44) heated to 270 占 폚 to prepare pellets. The physical properties according to comparative examples are measured and reported in Table 2 below.

[Comparative Example 5] Production of flame retardant composition for PET

5.0% of polycyclohexylene dimethylene terephthalate (PCT) and 95.0% of flame retardant B were continuously introduced into a biaxial kneading extruder (Φ: 40 mm, L / D = 44) heated to about 240 to 350 ° C, melted and kneaded To prepare a flame retardant granule. Thereafter, 48.8% of polyethylene terephthalate (PET), 13.0% of the flame retardant granules prepared in advance, 30% of the glass fiber, 3.2% of the flame-retardant additive and 5.0% The mixture was melted and kneaded using a kneading extruder (?: 40 mm, L / D = 44) to prepare pellets. The physical properties according to comparative examples are measured and reported in Table 2 below.

[Comparative Example 6] Production of flame retardant composition for PET

(Φ: 40 mm, L / D = 40 mm) heated to about 200 to 270 ° C. was added to the flame-retardant additive (48.8% of PET, 30% of glass fiber, 13.0% of flame retardant C, 44), melted and kneaded to prepare pellets. The flame retardant C is a general brominated polystyrene flame retardant, SAYTEX 3010 from Albermale. The physical properties according to comparative examples are measured and reported in Table 2 below.

[Comparative Example 7] Production of flame retardant composition for PET

(Φ: 40 mm) extruded from a polyethylene terephthalate (PET) 43.8%, a glass fiber 30%, a flame retardant C 13.0%, a flame retardant aid 3.25%, an impact modifier 5.0% , L / D = 44), melted and kneaded to prepare pellets. The physical properties according to comparative examples are measured and reported in Table 2 below.

division		Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4	Comparative Example 5	Comparative Example 6	Comparative Example 7
PET resin (unit:% by weight)		52.5	48.8	45.0	48.8	48.8	48.8	43.8
PBT resin (unit: wt%)		-	-	-	0.65	-	-	-
PCT resin (unit:% by weight)		-	-	-	-	0.65	-	-
Glass fiber (unit: wt%)		30.0	30.0	30.0	30.0	30.0	30.0	30.0
Flame retardant A (unit: wt%)		-	-	-	-	-	-	-
Flame retardant B (unit: wt%)		10.0	13.0	16.0	12.35	12.35	-	-
Flame Retardant C (Unit: wt%)		-	-	-	-	-	13.0	13.0
Flame Retarding Adduct (Unit: wt%)		2.50	3.25	4.00	3.2	3.2	3.25	3.25
Impact modifier (unit: wt%)		-	-	-	-	-	-	5.0
Other additives (% by weight)		5.0	5.0	5.0	5.0	5.0	5.0	5.0
Br content	%	6.85	8.91	10.96	8.46	8.46	8.91	8.91
Impact strength (J / m)	3.2 mm	66.4	64.7	62.8	65.2	64.4	61.3	66.7
	6.4 mm	55.7	53.4	47.8	53.7	53.0	52.1	57.1
The tensile strength	MPa	1,420	1,390	1,380	1,392	1,375	1,339	1,384
Flexural strength	MPa	1,835	1,830	1,828	1,838	1,793	1,772	1,821
liquidity		14.7	13.0	10.8	16.1	15.7	11.3	10.5
Flammability (sec)		2.5	2.0	1.3	2.7	1.9	2.3	3.0

In Comparative Examples 1 to 3, flame retardants and flame-retardant auxiliaries were used in the same amounts as in Examples 1 to 3, and when these were compared, it was found that the use of the flame retardant A improved the impact strength. Examples 4 to 5 are examples for securing the glass fiber content range. Specifically, when the glass fiber was adjusted at 15 to 45% by weight, the impact strength was 70.0 J / m, , It can be seen that the impact strength is improved by using the flame retardant A regardless of the content of the glass fiber.

Compared with Example 6, Comparative Example 4 shows the difference between when (i) polybutylene terephthalate and flame retardant B are mixed beforehand and (ii) when they are mixed with other components at one time. In comparison between Comparative Example 5 and Examples 6 to 7, polybutylene terephthalate and polyethylene terephthalate were mixed with a flame retardant in advance to obtain an effect of improving the impact strength. However, when polycyclohexylene dimethylene terephthalate The above effect can not be obtained. This is because the polycyclohexylene dimethylene terephthalate has a high melting temperature and is not sufficiently mixed when premixed with the flame retardant. In Examples 6 to 7, the absolute content of the flame retardant B is different from that of Comparative Example 2, but when the same type of flame retardant is used, the impact strength of Examples 6 to 7, The better. This shows that the use of a flame retardant and a polyester in advance is superior to the flame retardant in terms of impact strength.

Compared with Examples 2 and 6 to 7, Comparative Example 7 shows a higher effect than using an impact modifier in order to improve the impact strength by mixing the flame retardant with polyester in advance.

Therefore, it was confirmed that when the flame retardant A as a whole was used, or when a flame retardant mixed with a part of the flame retardant and a part of the polyester was used before the whole compounding process, the impact strength was improved by about 5 to 25%

Claims (9)

1. Polyethylene terephthalate resin; And

   Containing flame retardant,

   The content of the flame retardant relative to 100 parts by weight of the polyethylene terephthalate resin is 15 to 45 parts by weight,

   Wherein the flame retardant is prepared by preliminarily melt mixing the polystyrene bromide and the polyester, and the content of the polyester is 2 to 10 parts by weight based on 100 parts by weight of the flame retardant.
2. The flame-retardant polyethylene terephthalate resin composition according to claim 1, wherein the bromine content of the brominated polystyrene is 60 to 75% by weight.
3. The flame-retardant polyethylene terephthalate resin composition according to claim 1, wherein the polyethylene terephthalate resin has an intrinsic viscosity of 0.3 to 0.9 cm 3 / g, and the polyester resin has an intrinsic viscosity of 0.3 to 1.2 cm 3 / g.
4. The flame-retardant polyethylene terephthalate resin composition according to claim 1, wherein the polyester is polyethylene terephthalate or polybutylene terephthalate.
5. The flame-retardant polyethylene terephthalate resin composition according to claim 1, wherein the impact strength to a 3.2 mm test piece according to ASTM D256 is 70 J / m or more.
6. The composition of claim 1, further comprising a flame retardant adjuvant selected from the group consisting of antimony compounds, antimony trioxide, sodium antimonate, and compounds thereof, and glass fiber, wollastonite, calcium silicate, montmorillonite, Layered silicate nanoclay, Mica, Talc, and a compound thereof. The flame retardant polyethylene terephthalate resin composition of claim 1,
7. [7] The method according to claim 6, wherein the content of the filler is 20 to 150 parts by weight, the content of the flame retardant is 15 to 40 parts by weight, and the content of the flame retardant is 3 to 12 parts by weight based on 100 parts by weight of the polyethylene terephthalate resin. Flame retardant polyethylene terephthalate resin composition.
8. Blending the brominated polystyrene and the polyester in advance to prepare a flame retardant;

   And melting and mixing the flame retardant and polyethylene terephthalate.
9. The method for producing a flame-retardant polyethylene terephthalate resin according to claim 8, wherein the content of the polyester is 2 to 10 parts by weight based on 100 parts by weight of the flame retardant.