JP4500944B2 - Flame retardant ABS resin and method for producing the same - Google Patents

Description

  The present invention relates to an ABS resin to which siloxanes or silsesquioxanes are bonded, and a flame retardant ABS resin having a drip suppression effect during thermal decomposition or combustion.

ABS resin has excellent properties such as processability, dimensional stability, electrical properties, mechanical properties, and chemical stability, so it can be used in a wide range of fields such as transportation equipment, electrical and electronic equipment, housing equipment, and general merchandise. Has been used. However, the use of ABS resins is limited because they are flammable, and there are many application fields that require flame retardance in order to minimize damage during fires. And the method of making it flame-retardant by a synergistic effect by adding antimony trioxide and the like has been employed (see, for example, Patent Document 1). However, the toxicity of halogen-based gases generated during combustion has become a problem, and the development of a flame-retardant method that does not generate these halogen-based gases has been desired.
Further, as non-halogen flame retardants added to ABS-based resins, phosphate esters are known (for example, see Non-Patent Document 1), but the performance is still insufficient, and phosphate esters are also included. The inherent hydrolyzability is also regarded as a problem in relation to the stability of resin physical properties. Furthermore, it is said that the environmental impact of phosphorus compounds is usually less than that of halogen compounds, but it is not always clear.

  On the other hand, in order to prevent the spread of damage due to the spread of fire at the time of fire, flame-retardant standards such as UL-94, JIS Z 2391, etc., are evaluated as the burning rate and dripping while dripping softened material (drip ) Has been incorporated into the regulations. For this reason, in addition to the additive that makes the polymer itself difficult to burn, an additive that suppresses drip that causes fire spread to others is also added. As an additive for suppressing this drip, a fluororesin is often used (for example, see Patent Document 2), but it is known that a fluororesin generates a toxic gas at a high temperature. On the other hand, although silicon-based additives are considered to have no toxicity derived from elements, they have problems such as the additive exuding during molding.

Japanese Patent Laid-Open No. 10-147692 JP-A-6-9887 The book “High-functionality / reforming technology for olefinic and styrenic resins”, Technical Information Association, 2000, p320

  The present invention has been made in view of the above-described actual situation in the prior art. That is, an object of the present invention is to provide a flame-retardant ABS-based resin that does not generate harmful substances that adversely affect the environment and the human body, has a reduced combustion rate, and has suppressed drip.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors bonded a specific silicon-based compound to an ABS-based resin, thereby reducing the combustion rate during combustion and effectively reducing drip. It has been found that a flame-retardant ABS-based resin can be obtained, and based on this fact, the present invention has been completed.

That is, the present invention provides the following (1) to (3).
(1) Obtained by reacting a vinyl cyanide compound and a vinyl compound containing an aromatic vinyl compound with a conjugated diene polymer in which a siloxane or silsesquioxane having a Si—H bond is bonded by a hydrosilylation reaction. ABS based resin. This ABS resin is a flame retardant thermoplastic resin excellent in low burning rate and drip suppression effect.
(2) A siloxane or silsesquioxane having a Si—H bond is bonded to a conjugated diene polymer by a hydrosilylation reaction, and then a vinyl cyanide compound and an aromatic vinyl compound, and optionally other vinyl compounds. Is added to cause a polymerization reaction, and this is a method for producing an ABS resin.
(3) Conjugated diene polymers in which siloxanes or silsesquioxanes having Si-H bonds are bonded in advance by a hydrosilylation reaction, a vinyl cyanide compound and an aromatic vinyl compound, and optionally other vinyl compounds. Is a method for producing a flame-retardant ABS-based resin having a low combustion rate and a drip-suppressing effect.

  According to the present invention, it is possible to easily produce an ABS-based resin having a flame retardancy with a low combustion speed and excellent drip resistance during combustion.

  The ABS resin of the present invention comprises a conjugated diene polymer, which is an intermediate to the ABS resin, and siloxanes or silsesquioxanes having Si—H bonds, and then a vinyl cyanide compound and an aromatic compound according to a conventional method. It is obtained by subjecting a group vinyl compound to a polymerization reaction, particularly a graft polymerization reaction. The ABS resin thus obtained is a flame-retardant thermoplastic resin that has a low combustion rate during combustion, does not generate harmful chemical substances, and has improved drip resistance.

  As the conjugated diene polymer used in the production of the ABS resin in the present invention, any conjugated diene polymer can be used as long as it contains a conjugated diene in the monomer, and includes homopolymers, copolymers, and the like. , Polybutadiene, polyisoprene, butadiene-isoprene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene rubber, ethylene-propylene-butadiene copolymer, and the like. Among them, polybutadiene is preferable.

  In addition, as siloxanes or silsesquioxanes having Si—H bonds to be bonded to the conjugated diene polymer, those having at least one Si—H bond in the molecule can be used. Examples include pentamethyldisiloxane, tetramethyldisiloxane, heptamethyltrisiloxane, octamethyltetrasiloxane, methyltris (dimethylsiloxy) silane, tetramethylcyclotetrasiloxane, pentamethylcyclopentasiloxane, octakis (dimethylsiloxy) octa Silsesquioxane, Octakis (hydridosilsesquioxane), hydridosilsesquioxane, H-terminated polydimethylsiloxane, methyl H siloxane-dimethyl siloxane copolymer, polymethyl H siloxane, polyethyl H Rokisan, polyphenyl (dimethyl H siloxy) siloxane H end, methyl H siloxane - phenyl methyl siloxane copolymer, methyl H siloxane - octylmethylsiloxane copolymer, such as H siloxane Q resin and the like.

  The amount of these siloxanes or silsesquioxanes having a Si-H bond is not particularly limited, but is preferably 1 to 0.001 with respect to the total amount of carbon-carbon double bonds in the conjugated diene polymer. The molar equivalent, more preferably 0.7 to 0.01 equivalent.

  In the present invention, a conjugated diene polymer and a siloxane or silsesquioxane having a Si-H bond are bonded by a hydrosilylation reaction of an olefinic double bond. The hydrosilylation reaction is preferably carried out in the presence of a catalyst, and a known transition metal catalyst or radical initiator catalyst is used. Transition metal complexes include iron pentacarbonyl, ruthenium trichloride, dicobalt octacarbonyl, tristriphenylphosphine rhodium chloride, iridium trichloride, bistriphenylphosphine ethylene nickel, bistriphenylphosphine nickel dichloride, tetrakistriphenylphosphine palladium, bistriphenyl. Examples thereof include phosphine palladium dichloride, tristriphenylphosphine platinum, ethylene platinum dichloride dimer, chloroplatinic acid, platinum divinyltetramethyldisiloxane complex, and the like. Examples of the radical initiator catalyst include benzoyl peroxide, ditertiary butyl peroxide, 2,2'-azobis (isobutyronitrile) and the like. The catalyst to be used is preferably one containing platinum, particularly a platinum divinyltetramethyldisiloxane complex. Although there is no restriction | limiting in particular in the usage-amount of these catalysts, Preferably 0.5-0.00001 equivalent of the total amount of the olefinic double bond to react, More preferably, 0.1-0.001 equivalent is used.

  As the solvent used for the hydrosilylation reaction, any solvent can be used except those containing active hydrogen or aliphatic double bonds that may react with the raw material. For example, toluene, xylene, Examples include hexane, heptane, cyclohexane, and tetrahydrofuran. The amount of the solvent used may be 0.1 to 1000 times, preferably 1 to 200 times the total weight of the reaction raw materials.

  Although there is no restriction | limiting in particular in the reaction temperature of hydrosilylation, Preferably it is -20-200 degreeC, More preferably, it carries out at 0-150 degreeC. The reaction time is not particularly limited, but a long time is required when the reaction temperature is lowered, but a reaction time of 1 minute to 10 days is used depending on the reaction temperature.

  Next, the reaction product solution in which siloxanes or silsesquioxanes having Si-H bonds are bonded to the conjugated diene polymer obtained as described above is directly or after being concentrated to an appropriate degree or dried. Then, it is used for the graft polymerization reaction with the vinyl cyanide compound and aromatic vinyl compound, which is the next step, to produce an ABS resin.

  As the vinyl cyanide compound, acrylonitrile, methacrylonitrile, vinylidene cyanide, or the like can be used. A vinyl cyanide compound can be used individually by 1 type or in mixture of 2 or more types. Of these vinyl cyanide compounds, acrylonitrile is preferred.

  As the aromatic vinyl compound, styrene and its substituted product or derivative are used. Examples of styrene substitution products or derivatives include α-alkylstyrenes such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 3,5-dimethylstyrene, 1-vinyl naphthalene etc. can be mentioned, These aromatic vinyl compounds can be used individually by 1 type or in mixture of 2 or more types. Among these aromatic vinyl compounds, styrene, m-methylstyrene, and p-methylstyrene are preferable, and styrene is particularly preferable.

  The ratio of the conjugated diene polymer to which the siloxane or silsesquioxane having a Si-H bond is bonded to the vinyl cyanide compound and the aromatic vinyl compound is not particularly limited, but is preferably a conjugated diene polymer. 1 to 50 parts by weight of vinyl cyanide compound and 1 to 10 to 20 parts of aromatic vinyl compound, more preferably 1 part by weight with respect to 1 part of conjugated diene polymer. Graft polymerization is carried out using 1 / 20-5 parts of vinyl cyanide compound and 1 / 2-10 parts of aromatic vinyl compound.

  Furthermore, 0 to 20% by weight of another vinyl compound copolymerizable with the vinyl cyanide compound or the aromatic vinyl compound may be included in the monomer mixture. Examples of such vinyl compounds include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate.

  Graft polymerization can be performed by a known method, and bulk polymerization, emulsion polymerization, emulsion suspension polymerization, emulsion bulk polymerization, and the like can be used as appropriate, and bulk polymerization is preferred. In this graft polymerization, a generally known radical initiator can be used. Examples thereof include dicumyl peroxide, benzoyl peroxide, ditertiary butyl peroxide, 2,2'-azobis (isobutyronitrile) and the like. The amount used is arbitrary, but it is preferably in the range of 1/20000 to 1/20, preferably about 1/2000 to 1/100 by weight with respect to the conjugated diene polymer. Although there is no restriction | limiting in particular in the reaction temperature of graft polymerization, If reaction rate is considered, the range of 50-200 degreeC is preferable, and the range of 70-150 degreeC is especially preferable. The reaction time is not particularly limited, but a reaction time of about 1 to 2 days is desirable. After the graft polymerization reaction is completed, the solvent and unreacted low-boiling substances are removed under reduced pressure, and an ABS resin to which siloxanes or silsesquioxanes having Si-H bonds are bonded can be obtained.

  The ABS resin thus obtained was molded in accordance with a conventional method, and the flame retardancy was evaluated by the HB method in accordance with UL-94. As a result, the combustion rate was suppressed and drip was hardly generated during combustion. It was confirmed that it was suppressed by.

  The ABS resin of the present invention can be used alone, but can also be used as a resin composition in which an appropriate amount is mixed with other resins. Other resins to be mixed with the ABS resin are not particularly limited, and various resins can be appropriately selected depending on the purpose of use. For example, polycarbonate resins, polyolefin resins, polystyrene resins Examples thereof include resins, acrylic resins, polyamide resins, polyarylene ether resins, polylactic acid resins, and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited at all by these Examples.
Example 1

1.0 g of polybutadiene (Aldrich, 38,369-4, 1,2-added 20%), 1.6 g of octakis (hydridosilsesquioxane), 150 ml of toluene and a xylene solution of platinum divinyltetramethyldisiloxane complex ( 20 μL of Gelest Corp. (SIP6831.0) was placed in a 500 ml round bottom flask and stirred for 5 days at room temperature with a magnetic stirrer. Then, it concentrated to 5 ml under room temperature pressure reduction.
Next, the concentrated solution was transferred to a stainless steel pressure vessel, and reacted with 5 ml of styrene, 2 ml of acrylonitrile and 2 mg of dicumyl peroxide in a 110 ° C. water bath overnight. Thereafter, the reaction product was taken out, and the solvent was removed under a vacuum of 0.1 mmHg to obtain an ABS resin as a target product.

When the infrared absorption spectrum (KBr tablet, cm ⁻¹ ) of the obtained resin was measured, 2927 (m), 2267 (m, SiH and CN), 1495 (m), 1454 (m), 1130 (s, SiO ), 877 (s, SiO), 760 (m), and 700 (s).
The absorption spectrum was obtained from the Acrylic nitrile / butadiene / styrene resin value of Acrytronitral / butadiene / styrene resin from the Aldrich Library of Infrared Spectra Edition III (1981 Aldrich Chemical Company) p1597. 92 (1970) p5587, and the infrared absorption spectrum of octakis (hydridosilsesquioxane) was referred to. As a result, the obtained resin was confirmed to be an ABS resin to which silsesquioxane was bonded.
Next, as a result of evaluating the flame retardancy and drip property of the ABS resin test piece, which was filled in an injection mold and thermoformed, by the HB method in accordance with UL-94, no drip was observed during combustion, and combustion The speed was 13 mm / min.
Example 2

The reaction was carried out in the same manner as in Example 1 except that 1.6 g of octakis (hydridosilsesquioxane) used in Example 1 was replaced with 0.8 g. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the combustion rate was 14 mm / min.
Example 3

The reaction was performed in the same manner as in Example 1 except that the amount of octakis (hydridosilsesquioxane) used in Example 1 was changed to 0.4 g. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the combustion rate was 17 mm / min.
Example 4

The polybutadiene used in Example 1 (Aldrich, 38,369-4, 1,2-added 20%) was replaced with other polybutadiene (Aldrich, 46,686-7, 1,2-added 62%). The reaction was carried out in the same manner as in Example 1 except that the substitution was made. The obtained ABS resin to which the silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the combustion rate was 13 mm / min.
Example 5

The polybutadiene used in Example 1 (Aldrich 38,369-4, 1,2-added 20%) was replaced with another polybutadiene (Aldrich 43,478-7, 1,2-added 1%). Except for this, the reaction was carried out in the same manner as in Example 1. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the combustion rate was 12 mm / min.
Example 6

Except that 1.6 g of octakis (hydridosilsesquioxane) used in Example 1 was replaced with 1.6 g of H-terminal polydimethylsiloxane (manufactured by Gelest, DMS-H03), the same procedure as in Example 1 was performed. Reacted. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the burning rate was 12 mm / min.
Example 7

Except for replacing 1.6 g of octakis (hydridosilsesquioxane) used in Example 1 with 1.6 g of methyl H siloxane-phenyl methyl siloxane copolymer (Gerest, HPM-502), exactly the same as Example 1. The reaction was conducted in the same manner. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the combustion rate was 12 mm / min.
Example 8

Except for replacing 1.6 g of octakis (hydridosilsesquioxane) used in Example 1 with 1.6 g of hydridosilsesquioxane (manufactured by Dow Corning, FOx-16), exactly the same as Example 1. And reacted. The obtained ABS resin to which silsesquioxane was bonded was evaluated in the same manner. As a result, no drip was observed during combustion, and the burning rate was 19 mm / min.
Comparative Example 1

Place in a 110 ° C water bath with 1 g of polybutadiene (Aldrich, 38,369-4, 1,2-added 20%), 2 ml of toluene, 5 ml of styrene, 2 ml of acrylonitrile, 2 mg of dicumyl peroxide in a stainless steel pressure vessel. And heated overnight to react. Thereafter, the reaction product was taken out, and the solvent was removed under a vacuum of 0.1 mmHg to obtain an ABS resin.
Next, as a result of evaluating the flame retardancy and drip property of the ABS resin test piece, which was filled in an indentation mold and thermoformed, by the HB method according to UL-94, drip was recognized during combustion, and the burning rate Was 30 mm / min.
Comparative Example 2

  A commercially available ABS resin (manufactured by Kanto Chemical Co., Ltd., 31080-1A) is filled into a mold, and a heat-molded ABS resin test piece is evaluated for flame retardancy and drip by the HB method according to UL-94. As a result, drip was observed during combustion, and the combustion rate was 25 mm / min.

  From the above examples, the ABS resin produced by bonding silsesquioxanes to the polybutadiene of the present invention is an ABS resin produced from commercially available ABS resin and polybutadiene not bonded to silsesquioxanes. It was confirmed that the burning rate was slower than that of the resin and that drip was suppressed during the burning.

  The ABS resin of the present invention is an ABS resin bonded with a silicon compound, and is a flame retardant thermoplastic resin that has a slow combustion rate and can suppress the occurrence of drip, which is a problem during combustion. Therefore, it can be used in a wide range of fields because it is safe at the time of combustion without adding a flame retardant or a drip inhibitor that may cause

Claims (5)

ABS system obtained by reacting a vinyl cyanide compound and a vinyl compound containing an aromatic vinyl compound to a conjugated diene polymer in which siloxanes or silsesquioxanes having Si-H bonds are bonded by a hydrosilylation reaction. resin. The ABS resin according to claim 1, which is a flame retardant thermoplastic resin having a low burning rate and an excellent drip suppression effect. After siloxanes or silsesquioxanes having Si-H bonds are bonded to a conjugated diene polymer by a hydrosilylation reaction, a vinyl cyanide compound and an aromatic vinyl compound, and optionally other vinyl compounds are added. A method for producing an ABS resin, characterized by carrying out a polymerization reaction. A vinyl cyanide compound, an aromatic vinyl compound, and optionally other vinyl compounds are added to a conjugated diene polymer in which a siloxane or silsesquioxane having a Si—H bond is bonded in advance by a hydrosilylation reaction. A method for producing a flame-retardant ABS-based resin having a low burning rate obtained by a polymerization reaction and having a drip suppressing effect A resin composition comprising the ABS resin according to claim 1 as a constituent component.