KR20030026841A - Styrene based thermoplastic resin composition having superior fireproof properties - Google Patents

Abstract

PURPOSE: Provided is a styrene-based thermoplastic resin composition containing a non-halogen-based fire-retardant agent excellent in fire-retardancy and impact-resistance. CONSTITUTION: The styrene-based thermoplastic resin composition contains: 100pts.wt. of a base resin containing 10-50pts.wt. of a graft copolymer containing rubber-modified styrene, 5-20pts.wt. of a phenol novolac resin of formula 1, 30-70pts.wt. of a styrene-contained copolymer, and additionally 10-40pts.wt. of a thermoplastic polyurethane resin; 5-20pts.wt. of an aromatic phosphate such as an aromatic monophosphate, an aromatic diphosphate, or a mixture thereof.

Description

Styrene-based thermoplastic resin composition excellent in flame retardancy {STYRENE BASED THERMOPLASTIC RESIN COMPOSITION HAVING SUPERIOR FIREPROOF PROPERTIES}

The present invention relates to a styrene-based thermoplastic resin composition, and more particularly to a styrene-based thermoplastic resin composition containing a non-halogen-based flame retardant excellent in flame resistance and excellent impact strength.

Rubber modified styrene resins have excellent processability and physical properties. In addition, it has excellent appearance and impact strength, so it is widely used in electrical and electronic products and office equipment. Since electrical and electronic products and office equipment generate a lot of heat when used, there is a risk of fire, so the resin used should be flame retardant. Accordingly, studies are continuously conducted to impart flame retardancy to rubber-modified styrene-based resins that have a good burning property.

As a result of a long study, it is known that the use of halogen-based compounds as flame retardants is the most effective method for flame retardant rubber modified styrene resins. Tetrabromobisphenol A and brominated epoxy are the most commonly used halogen flame retardants, and it is well known that antimony compounds play a role of increasing flame retardancy.

However, halogen-based compounds are known to generate gases that corrode molds during processing and to decompose and release toxic gases that are harmful to human bodies. In particular, bromine compounds have been controversial because they can generate harmful environmental hormones such as dioxin and furan when they are combusted. Antimony compounds are also classified as toxic.

Accordingly, much attention has been focused on the study of the flame retardant resin composition without using a halogen compound and antimony. Since rubber-modified styrene resins are difficult to obtain excellent flame retardancy when using non-halogen flame retardants, many methods of blending polycarbonates with styrene resins have been attempted. However, polycarbonate / styrene blends require at least 70% by weight of polycarbonate to achieve the expected flame retardancy. When polycarbonate is used in this way, it is difficult to take advantage of the rubber-modified styrene-based resin, and it is inferior in processability and economic efficiency.

In addition, the non-halogen flame-retardant method of the rubber-modified styrene resin that does not use polycarbonate includes a resin composition method containing phosphorus or expandable graphite, but it has a disadvantage in that it can be manufactured only with a product having poor physical properties and a dark color.

An object of the present invention is to provide a styrene-based thermoplastic resin composition containing a non-halogen-based flame retardant having excellent flame resistance and excellent impact resistance in consideration of the problems of the prior art.

The present invention, in order to achieve the above object, in the flame retardant styrene-based thermoplastic resin composition,

a) 10 to 50 parts by weight of rubber modified styrene-containing graft copolymer;

Ii) 5 to 20 parts by weight of a phenol novolak resin; And

Iii) 30 to 70 parts by weight of styrene-containing copolymer

100 parts by weight of a base resin containing; And

b) 5 to 20 parts by weight of aromatic phosphate

It provides a flame retardant styrene-based thermoplastic resin composition comprising a.

Preferably, the base resin of a) provides a flame-retardant styrene-based thermoplastic resin composition which further comprises 10 to 40 parts by weight of i) thermoplastic polyurethane resin.

Hereinafter, the present invention will be described in detail.

The present invention blends a small amount of thermoplastic polyurethane resin and phenol novolac resin in place of polycarbonate to maintain the advantages of rubber modified styrene resin, and by using aromatic phosphate as flame retardant, it has excellent physical properties such as flame retardancy and impact strength. It is to be able to obtain a thermoplastic resin composition.

(Rubber-modified styrene-containing graft copolymer)

The rubber-modified styrene-containing graft copolymer used in the present invention is 30 to 65 parts by weight of at least one of styrene, alphamethyl styrene and nuclear substituted styrene, and at least one of acrylonitrile, methyl methacrylate and butyl acrylate. It is resin which grafted the compound containing 10-30 weight part to 10-60 weight part of rubber | gum. Examples of the rubber include polybutadiene, styrene-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer and the like. Although this graft copolymer resin can be manufactured by a normal polymerization method, it is preferable to synthesize | combine it by block polymerization and emulsion polymerization. In particular, the acrylonitrile / butadiene / styrene (ABS) resin which grafted acrylonitrile and styrene to butadiene rubber is more preferable.

The rubber-modified styrene-containing graft copolymer comprises a base resin together with a thermoplastic polyurethane resin, a styrene-containing copolymer, and a phenol novolak resin, and the rubber-modified styrene-containing graft copolymer is in the range of 10 to 50 parts by weight in the total base resin. Used as If the amount of the rubber-modified styrene-containing graft copolymer is less than 10 parts by weight, the physical properties including impact strength are lowered. If the rubber-modified styrene-containing graft copolymer is less than 50 parts by weight, the workability is lowered and the rigidity and hardness are lowered.

(Thermoplastic polyurethane resin)

The thermoplastic polyurethane resin used in the present invention is a generic term for a polymer produced by the polymer addition reaction of a compound having two or more hydroxyl groups and a polyfunctional isocyanate. Thus, the thermoplastic polyurethane resin may include other types of bonds other than urethane bonds, such as urea, amides, droplets, allophanates, ethers or ester bonds.

The thermoplastic polyurethane resin is composed of a rubber-modified styrene-containing graft copolymer, a styrene-containing copolymer, and a phenol novolak resin, and is used in the range of 10 to 40 parts by weight in the total base resin. If the amount of the thermoplastic polyurethane resin is less than 10 parts by weight, flame retardancy is lowered, and if it exceeds 40 parts by weight, workability is poor.

(Phenolic novolac resin)

The phenol novolak resin used in the present invention is a resin obtained by reacting phenols with formalin under an acidic catalyst and has a structure as shown in the following formula (1), and is used in the range of 5 to 20 parts by weight in the total base resin. When the usage-amount of the said phenol noblock resin is used less than 5 weight part, a flame retardance does not appear and when it exceeds 20 weight part, workability will fall.

[Formula 1]

In Formula 1, X is CH ₂ , CH ₂ CH ₂ , CHCH ₃ , CO, or SO ₂ ; Each R is independently or simultaneously a hydrogen atom, a halogen atom, a C _{1 to} C ₂₀ alkyl group, an aryl group, NO ₂ , CN, Si, or a hydroxy group; n is a polymerization degree which is an integer of 1 or more.

(Styrene-containing copolymer)

The styrene-containing copolymer used in the present invention is 50 to 90 parts by weight of at least one of styrene, alphamethyl styrene and nuclear substituted styrene, and 10 to 50 parts by weight of at least one of acrylonitrile, methyl methacrylate and butyl acrylate. Contains wealth. Such graft copolymer resins can be prepared by conventional polymerization methods, but those synthesized by bulk polymerization and emulsion polymerization are suitable. The styrene-containing copolymer is used in the range of 30 to 70 parts by weight based on the amount of the rubber-modified styrene-containing graft copolymer, the thermoplastic polyurethane resin, and the phenol novolak resin.

(Flame retardant; aromatic phosphate)

In the present invention, the aromatic phosphate used as the flame retardant may be used in combination with an aromatic monophosphate and an aromatic diphosphate, respectively.

The aromatic monophosphate is trialkyl phosphate such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, halogen substituted, triphenyl phosphate, tricresyl phosphate, trigyyl phosphate, cresyl diphenyl phosphate, etc. Triarylphosphates, and trialkyl-arylphosphates such as octyldiphenylphosphate. Preferably triarylphosphates are used, more preferably triphenylphosphate, tri (4-methylphenyl) phosphate and tri (2,6-dimethylphenyl) phosphate.

In addition, the aromatic diphosphate is preferably a compound of formula (2), and pentaerythritol diphosphate (hereinafter, referred to as PPP) of formula (3).

[Formula 2]

In Chemical Formula 2,

Ar _{1 to} Ar ₄ are aryl groups in which 1 to 3 phenyl groups or alkyl groups of 1 to 4 carbon atoms are substituted, R is phenyl or bisphenol a, and n is 4 or 5, a degree of polymerization.

[Formula 3]

The aromatic monophosphate and the aromatic diphosphate are preferably added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the total base resin, respectively or mixed. If the amount of the flame retardant is less than 5 parts by weight, flame retardancy is lowered. If the amount of the flame retardant is greater than 20 parts by weight, the flame retardancy is excellent, but workability is poor, and other physical properties such as impact strength are lowered.

The composition of the present invention may further include at least one additive selected from the group consisting of lubricants, heat stabilizers, antioxidants, light stabilizers, anti-drip agents, pigments, and inorganic fillers, depending on the use, in addition to the above components.

Such a flame retardant styrenic thermoplastic resin composition of the present invention can be prepared by mixing in a conventional blending method.

The present invention will be described in more detail with reference to the following examples. However, an Example is for illustrating this invention and is not limited only to these.

EXAMPLE

The production method and specifications of the raw material components used in the following examples are as follows.

(Rubber modified styrene-containing graft copolymer)

Rubber modified styrene-containing graft copolymer resin is LG Chemical Co., Ltd., 30 parts by weight of acrylonitrile / butadiene / styrene resin grafted acrylonitrile and styrene on butadiene rubber, 15 parts by weight of acrylonitrile, It contains 50 parts by weight of butadiene rubber and is synthesized by emulsion polymerization.

(Thermoplastic polyurethane resin)

The thermoplastic polyurethane resin is prepared by reacting adipic acid with glycol and diisocyanate. In the manufacturing method, adipic acid is reacted with a mixture of an excess of ethylene glycol and polypropylene glycol to make a polyester, and a diisocyanate is reacted thereto to prepare a compound having a urethane structure. 1 g of water is added to 100 g of this compound, and the solid powder obtained by heating is applied at a pressure of 100 atm while heating to 150 ° C. to obtain a thermoplastic polyurethane resin.

(Phenolic novolac resin)

The phenol novolac resin is prepared by synthesizing a compound having a structure of x in formula (1) having an average polymerization degree of 5 and a softening point of 130 ° C. 1 mole of phenol and formalin are added to the reactor, and 1.5 g of oxalic acid is added as a catalyst and reacted at 97 ° C. for 12 hours. After the reaction is completed, the resin and water are separated, and after removing the water, dehydration is carried out again under reduced pressure, heated at 180 ° C. for 1 hour, cooled, and a solid novolak-type phenolic resin is obtained.

(Styrene-containing copolymer)

The styrene-containing copolymer contains 70 to 80 parts by weight of styrene and 20 to 30 parts by weight of acrylonitrile and is synthesized by emulsion polymerization.

(Aromatic phosphate)

Triphenyl phosphate (TPP) of Daihachi, Japan was used as aromatic mono phosphate. As the aromatic diphosphate, diphenyl phosphate (PX-200) manufactured by Daihachi, Japan, and pentaerythritol diphosphate (PPP) synthesized by LG Chemical were used.

Example 1

To prepare a flame-retardant thermoplastic resin composition in the composition and content as shown in Table 1. 10 parts by weight of a phenol novolak resin was blended with a styrene resin, and aromatic monophosphate (TPP) was used as a flame retardant at 15 parts by weight based on 100 parts by weight of the total resin.

Example 2

Except for using aromatic diphosphate (PX-200) 15 parts by weight based on 100 parts by weight of the total resin instead of aromatic monophosphate (TPP) as a flame retardant in Example 1 as shown in Table 1 A flame retardant thermoplastic resin composition was prepared according to the composition and content.

Example 3

Except that in Example 1, as the flame retardant, instead of aromatic monophosphate (TPP) using pentaerythritol diphosphate (PPP) 15 parts by weight based on 100 parts by weight of the total resin, the same method as in Example 1 shown in Table 1 A flame retardant thermoplastic resin composition was prepared according to the composition and content.

Example 4

Except for using the aromatic monophosphate (TPP) and aromatic diphosphate (PX-200) in 10 parts by weight, 5 parts by weight based on 100 parts by weight of the total resin as in Example 1, respectively, except that the flame retardant To prepare a flame-retardant thermoplastic resin composition according to the composition and content as shown in Table 1.

Flame retardance was measured according to the UL94 VB flame retardant test method for the specimen prepared in Examples 1 to 4 and the results are shown in Table 1 below.

Flame Retardant Evaluation Criteria

SE: Self-Extinguish, NR: No Rating

division Example One 2 3 4 Basic resin (parts by weight) Rubber modified styrene-containing graft copolymer DP215 35 35 35 35 Phenolic Novolak Resin 10 10 10 10 Styrene-containing copolymer SAN 55 55 55 55 Flame retardant (parts by weight) Aromatic monophosphate TPP 10 - - 5 Aromatic diphosphate PX-200 - 10 - 5 PPP - - 10 - Properties Flame Retardant (1/8 ") SE SE SE SE Average burn time (t1 + t2) 65 88 71 72

Example 5

As shown in the following Table 2, 20 parts by weight of the rubber-modified styrene-containing graft copolymer, 10 parts by weight of thermoplastic polyurethane resin, and 10 parts by weight of novolak resin were blended with 60 parts by weight of styrene-containing copolymer, and aromatic mono was used as a flame retardant. A flame retardant resin composition was prepared by adding and mixing 10 parts by weight of phosphate TPP based on 100 parts by weight of the total resin.

Example 6

A flame retardant resin composition was prepared in the same manner as in Example 5, except that TPP, which is an aromatic monophosphate, was increased to 15 parts by weight with respect to 100 parts by weight of the total resin as a flame retardant.

Example 7

A flame retardant resin composition was manufactured in the same manner as in Example 5, except that 15 parts by weight of aromatic diphosphate PX-200 was used based on 100 parts by weight of the total resin instead of TPP, which is an aromatic monophosphate, as a flame retardant.

Example 8

A flame retardant resin composition was manufactured in the same manner as in Example 5, except that 15 parts by weight of aromatic diphosphate PPP was used based on 100 parts by weight of the total resin instead of TPP, which is an aromatic monophosphate, as a flame retardant.

Example 9

A flame-retardant resin composition was prepared in the same manner as in Example 5, except that 8 parts by weight of aromatic monophosphate TPP and 5 parts by weight of aromatic diphosphate PX-200 were used as a flame retardant based on 100 parts by weight of the total resin.

Example 10

Among all the basic resins, thermoplastic polyurethane resin was increased to 20 parts by weight, styrene-containing copolymer was reduced to 50 parts by weight, and the flame retardant was 12 parts by weight of TPP, which is an aromatic monophosphate, based on 100 parts by weight of the total resin. A flame-retardant resin composition was prepared in the same manner as in Example 5 except for use in parts.

Example 11

A flame retardant resin composition was prepared in the same manner as in Example 10 except that the rubber-modified styrene-containing graft copolymer was used in an amount of 25 parts by weight and the styrene-containing copolymer was reduced to 45 parts by weight. It was.

Example 12

Among all the basic resins, a flame-retardant resin composition was prepared in the same manner as in Example 10 except that the thermoplastic polyurethane resin was increased to 30 parts by weight and the styrene-containing copolymer was reduced to 40 parts by weight.

Table 2 shows the results of measuring the impact strength and the flame retardancy of the compositions of Examples 5 to 12 and the specimens thus prepared. Impact strength was measured according to the ASTM D-256 conditions, flame resistance was measured according to the UL94 VB flame retardant standard.

division Example 5 6 7 8 9 10 11 12 Basic resin (parts by weight) Rubber modified styrene-containing graft copolymer DP215 20 20 20 20 20 20 25 20 Polyurethane 10 10 10 10 10 20 20 30 Phenol novolac 10 10 10 10 10 10 10 10 Styrene-containing copolymer SAN 60 60 60 60 60 50 45 40 Flame retardant (parts by weight) Aromatic monophosphate TPP 10 15 - - 8 12 12 12 Aromatic diphosphate PX-200 - - 15 - 5 - - - PPP - - - 15 - - - - Properties Impact strength (1/4 ") 22 19 18 17 20 23 26 28 Flame Retardant (1/8 ") V-1 V-1 V-1 V-1 V-1 V-0 V-0 V-0

UL-94 when 10 parts by weight of novolak resin and 10 parts by weight of thermoplastic polyurethane resin are blended together with the styrenic copolymer and 10 parts by weight or more of aromatic phosphate is used based on 100 parts by weight of the total resin as in Examples 5 to 9. The flame retardancy of V-1 was shown. In addition, the impact strength was different depending on the type of aromatic phosphate, but showed the same flame retardancy.

In addition, blending by adding 20 parts by weight or more of thermoplastic polyurethane resin as in Examples 10 to 12 showed a flame retardancy of UL-94 V-0, and the content of rubber modified styrene-containing graft copolymer or thermoplastic polyurethane resin. Increasing could increase the impact strength without changing the flame retardancy.

As described above, the composition of the present invention can produce a non-halogen styrene thermoplastic flame retardant resin composition having excellent flame retardancy and impact strength by adding a small amount of a novolak resin and a thermoplastic polyurethane resin to the rubber-modified styrene resin.

Claims (11)

In the flame retardant styrene-based thermoplastic resin composition, a) 10 to 50 parts by weight of rubber modified styrene-containing graft copolymer; Ii) 5 to 20 parts by weight of a phenol novolak resin; And Iii) 30 to 70 parts by weight of styrene-containing copolymer 100 parts by weight of a base resin containing; And b) 5 to 20 parts by weight of aromatic phosphate Flame retardant styrene-based thermoplastic resin composition comprising a. The method of claim 1, Flame retardant styrene-based thermoplastic resin composition further comprises 10 to 40 parts by weight of the base resin of i) thermoplastic polyurethane resin. The method of claim 2, Flame-retardant styrene-based thermoplastic resin composition is a resin prepared by the method comprising the step of polymerizing the thermoplastic polyurethane resin compound having at least two hydroxyl groups and a polyfunctional isocyanate. The method of claim 1, The flame-retardant styrene-based thermoplastic resin composition of the rubber modified styrene-containing graft copolymer of a) i) is a copolymer obtained by grafting 30 to 65 parts by weight of a styrene compound and 10 to 30 parts by weight of an acrylic compound in 10 to 60 parts by weight of rubber. . The method of claim 4, wherein The styrene compound is at least one selected from the group consisting of styrene, alphamethyl styrene, and nuclear substituted styrene, the acrylic compound is at least one selected from the group consisting of acrylonitrile, methyl methacrylate, and butyl acrylate. The rubber is a flame retardant styrene thermoplastic resin composition selected from the group consisting of polybutadiene, styrene-butadiene copolymer, polyisoprene, and butadiene-isoprene copolymer. The method of claim 1, Flame retardant styrene-based thermoplastic resin composition wherein the phenol novolak resin of a) ii) is a compound represented by the following formula (1): [Formula 1] In Chemical Formula 1, X is CH ₂ , CH ₂ CH ₂ , CHCH ₃ , CO, or SO ₂ ; Each R is independently or simultaneously a hydrogen atom, a halogen atom, a C _{1 to} C ₂₀ alkyl group, an aryl group, NO ₂ , CN, Si, or a hydroxy group; n is a polymerization degree which is an integer of 1 or more. The method of claim 1, 50 to 90 parts by weight of a compound in which at least one compound selected from the group consisting of styrene, alphamethyl styrene and nuclear substituted styrene is a styrene-containing copolymer of a) iii); And 10 to 50 parts by weight of a compound selected from the group consisting of acrylonitrile, methyl methacrylate and butyl acrylate. The method of claim 1, The flame-retardant thermoplastic resin composition of the b) is an aromatic phosphate, an aromatic diphosphate, or a mixture thereof. The method of claim 8, Trialkyl phosphate selected from the group consisting of trimethyl phosphate, triethyl phosphate, tributyl phosphate, and trioctyl phosphate, wherein the aromatic monophosphate is unsubstituted; Triaryl phosphate selected from the group consisting of triphenyl phosphate, tricresyl phosphate, trixyl yl phosphate, and cresyl diphenyl phosphate; And a trialkyl-aryl phosphate comprising octyl diphenyl phosphate. The method of claim 8, A flame retardant styrene thermoplastic resin composition wherein the aromatic diphosphate is a compound represented by the following formula (2) or (3): [Formula 2] In Chemical Formula 2, Ar _{1 to} Ar ₄ is a phenyl group or an aryl group substituted with 1 to 3 alkyl groups of 1 to 4 carbon atoms, R is phenyl or bisphenol a, n is the degree of polymerization of 4 or 5, [Formula 3] . The method of claim 1, The thermoplastic resin composition further comprises at least one additive selected from the group consisting of lubricants, heat stabilizers, antioxidants, light stabilizers, anti-drip agents, pigments and inorganic fillers.