JPH11140329A - Flame resistant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a flame resistant effect such as drip prevention without deteriorating functions of a resin composition by adding a mixture of a silicone and an inorganic compound such as a silica powder and the like with a thermoplastic resin. SOLUTION: As the inorganic filter to be added to a thermoplastic resin, a glass fiber or a powder of silica, quartz, aluminum silicate, mica, alumina, aluminum hydroxide, calcium carbonate, talc, iron oxide, graphite or the like can be used and a silica powder is preferable. A silica of which surface is treated with an organic silicon compound to seal the surface silanol is preferable. A silicone of which composing organic groups are an alkyl group, an alkenyl group and an aryl group are preferable and one composed of the methyl group and the phenyl group is further preferable. The silicone terminals are preferably sealed or reduced with a silanol. A mixture is prepared by dissolving a silicone into an organic solvent and a silica powder is dispersed well into it. Then not less than 1 part by weight of this mixture is added to 100 parts by weight of a thermoplastic resin to be made flame resisting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant resin composition which is made flame-retardant by adding a mixture of silicone and an inorganic substance to a thermoplastic resin composition.

[0002]

2. Description of the Related Art Flame-retardant resin compositions are widely used in products such as electric and electronic equipment parts, building materials, automobile parts, and daily necessities. Flame retardancy is generally imparted to these resin compositions by adding a halogen or phosphorus compound. However, the halogen and phosphorus compounds are highly reactive substances and have a drawback that they require careful handling. On the other hand, a technique is known in which a highly stable silicone compound is added to a resin composition in order to impart flame retardancy. Furthermore, by adding an inorganic filler in addition to the addition of the silicone compound, it is possible to exhibit more flame retardancy and to improve other physical properties.

For example, reference 1 (Japanese Patent Laid-Open No. 59-33319)
JP-A No. 2000-216, and JP-A No. 2002-138, which discloses a flame-retardant material comprising one or more polymers selected from an organopolysiloxane or a copolymer of an organic polymer substance containing no silicon atom and an organosilicone compound, and an inorganic filler. An epoxy resin composition has been described. Reference 2 (Japanese Unexamined Patent Application Publication No.
JP-A-113712) discloses that a free-flowing silicone polymer powder having an average particle size of 1 to 1000 μm adjusted by mixing a polyorganosiloxane with a silica powder filler is uniformly dispersed in an organic resin. A technique for making an organic resin flame-retardant is described.
Reference 3 (Japanese Patent Laid-Open No. Hei 7-268217) states that
Compositions comprising a polyorganosiloxane gum, a polyphenylene ether and a reinforcing filler, that is to say comprising fumed silica, are described as having a high flame retardancy.

[0004]

However, flame retardancy is insufficient with the conventional addition of silicone alone, and flame retardancy is not sufficient even with the addition of an inorganic filler in combination. In No. 1, a compound of a metal belonging to Group II or Group VIII is added in order to obtain more flame retardancy. Reference 4 (Japanese Unexamined Patent Publication No. 4-933)
No. 63) describes a flame-retardant resin composition comprising an organopolysiloxane and a synthetic resin component, but here, an organic bromine compound is also added thereto. Further, the flame-retardant resin composition described in Document 2 is said to have an effect of reducing heat emission and generation of smoke, and of generating toxic carbon monoxide. However, even in the flame-retardant resin composition described in Document 2, V-1 (thickness 3.2) was measured in the UL94 test.
mm) or more, it was necessary to use an organic halogen compound in combination. The UL94 test is a standard specified by Underwriters Laboratories as an index of the flame retardancy of a flame retardancy test of a plastic material for equipment parts.

That is, conventionally, sufficient flame retardancy has not been obtained unless a highly reactive compound such as an organic halogen compound is added. Further, even without using an organic halogen compound or the like, if the amount of addition of an inorganic filler or the like is increased, flame retardancy can be improved, but in this case, the strength required for the flame retardant resin composition and the like are reduced. You won't get it. Accordingly, the present invention has been made in order to solve the above problems, and it is possible to improve a flame retardant effect such as a drip prevention effect without lowering a function as a resin composition. The purpose is to do.

[0006]

In the flame-retardant resin composition of the present invention, a mixture of silicone and an inorganic substance is added to a thermoplastic resin. Silica powder was used as the inorganic substance, and the surface of the silica powder was alkylsilylated. As a result, even if the amount of the mixture added is reduced, sufficient flame retardancy is ensured.

[0007]

Embodiments of the present invention will be described below. The flame-retardant resin composition of the present invention is constituted by adding a mixture of silicone and an inorganic filler to a desired thermoplastic resin. What is necessary is just to use the following as this inorganic filler. That is, silica, quartz, aluminum silicate, mica, alumina, aluminum hydroxide, calcium carbonate, talc,
Silicon carbide, silicon nitride, boron nitride, titanium oxide, iron oxide,
Powders such as graphite and carbon, glass fibers and any mixtures thereof may be used. Particularly, silica powder is preferable.

[0008] Silanol is present on the surface of the silica, and the silanol is preferably reacted with an organosilicon compound having an alkyl group and sealed. The organic silicon compound for sealing is a compound of hydrocarbon and silicon having a functional group capable of reacting with silanol. For example, the hydrocarbon is a hydrocarbon having 1 to 10 carbon atoms, particularly preferably methyl, ethyl, phenyl, vinyl and the like. Further, examples of the functional group capable of reacting with silanol include chlorine and alkoxy. In the case of alkoxy, methoxy and ethoxy are preferred. Further, the form of silazanes is also preferable. Specific examples include trimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, hexamethylsilazane, phenyldimethylchlorosilane, phenyldimethylmethoxysilane, triphenylchlorosilane, and the like.

The surface treatment method of the silica powder with the organosilicon compound may be any method as long as the silanol on the surface of the silica powder can be sealed, and a known surface treatment method may be applied. it can. For example, the surface treatment of the silica powder can be performed by mixing and contacting the organosilicon compound while keeping the silica powder in a fluid state.
Further, silica powder, surface area 50 m ² / g or more, is more and still more preferably with more than 100 m ² / g,
Preferred for flame retardancy.

[0010] As the silicone, the formula R ₂ SiO
Units represented by _1.0 (D units), units of the formula RSiO _1.5 (T units), units of formula SiO _2.0 (Q
Unit), or some combination thereof. In particular, it is preferable for flame retardancy that the silicone contains a unit (T unit) represented by the formula RSiO _1.5 .

The organic group R constituting the silicone is
It may be an alkyl group, an alkenyl group, an aryl group, etc., particularly preferably a methyl group and a phenyl group, and more preferably a mixture thereof. Further, it is also _preferable that the end of the silicone is sealed with a unit (M unit) represented by the formula R ₃ SiO _0.5 to reduce silanol as much as possible in order to make the resin composition to which the silicone is added flame-retardant.

Next, as a method of mixing the silicone and the silica powder, a known method can be used as long as the silica powder can be sufficiently dispersed in the silicone dissolved in an organic solvent such as toluene, xylene or isopropyl alcohol at an arbitrary ratio. Either method may be used. For example, after mixing the above-mentioned silicone dissolved in an organic solvent at an arbitrary ratio into an apparatus such as a Henshal mixer, a universal mixer, or a kneader mixer, and thoroughly mixing the resultant, a mixture of the obtained silicone, silica powder, and an organic solvent is used. Thus, by removing the organic solvent by heating or the like, the above-mentioned mixture of silicone and silica powder is obtained.

Then, the mixture may be added to the thermoplastic resin whose flame retardancy is desired. Here, 1 part by weight or more of the mixture may be added to 100 parts by weight of the thermoplastic resin component. If the addition amount is less than that, the flame retardant effect decreases. However, if the addition amount is too large, properties such as moldability of the obtained flame-retardant resin composition will be deteriorated. Therefore, the thermoplastic resin component 100
It is better not to add more than 50 parts by weight of the mixture to parts by weight.

As the above-mentioned thermoplastic resin, for example, the following may be used. Polyethylene, polypropylene, polystyrene, high impact polystyrene,
Polycarbonate, polyphenylene ether, acrylonitrile, butadiene, styrene copolymer (AB
S), alloys of polycarbonate and ABS resin, polyethylene terephthalate and mixtures thereof. Among them, polycarbonate resin is particularly preferable. Further, a reinforcing agent may be added to the above-described flame-retardant resin composition as needed. Its reinforcing agents include antioxidants, neutralizers, ultraviolet absorbers, antistatic agents, pigments, dispersants, lubricants, thickeners, fillers, and the like. Generally, it is blended in a resin composition.

As a method of adding the above-mentioned mixture to the thermoplastic resin, mixing may be performed by using the same apparatus as in the case of forming a rubber plastic. For example, using a mixing stirrer such as a ribbon blender or a Henschel mixer, thoroughly mixing and dispersing the above-mentioned mixture and each raw material of the thermoplastic resin individually, and then kneading with a melt kneader such as a Banbury roll or an extruder. And a flame-retardant resin composition. In addition, after the kneading, a flame-retardant resin body can be obtained by molding into a desired shape by, for example, injection molding, extrusion molding, compression molding, vacuum molding, or the like.

[0016]

Embodiments of the present invention will be described below. First, adjustment of silicone will be described. (Silicone Preparation Example 1) A-1 of the structural unit shown in Table 1 below
A silane compound (chlorosilane, alkoxysilane) having the following composition and a required amount of a solvent (toluene, xylene) are placed in a predetermined flask. Next, when the silane solutions put in the flask become uniform, a required amount of water is dropped from the upper part of the flask within a certain time while stirring, and hydrolysis is performed. When the reaction is completed, the silicone resin layer and the aqueous layer formed in the flask are separated by a separating funnel. Next, water is added in order to remove hydrochloric acid and by-products in the silicone resin solution, and washing with heating is performed. After washing with water, liquid separation is performed to obtain a silicone resin solution. Then, the silicone resin solution was dissolved, filtered, and adjusted in concentration to obtain a silanol-containing silicone resin solution having a molecular weight (Mw) of 30,000 and a nonvolatile content of 50 wt%.

Then, in order to block (block) the silanol groups of the silicone resin, a necessary amount of hexamethyldisilazane is added thereto, and the mixture is heated and reacted at 80 ° C. for 3 hours to obtain a silicone resin having a terminal trimethylsilyl group. A solution was obtained. Then, by filtering and removing them, a silicone solid resin (silicone A-1) having a softening point of 70 ° C. and a molecular weight (Mw) of 30,000 was obtained.

(Silicone Preparation Example 2) A silane compound (chlorosilane, alkoxysilane) having a composition of silicone A-2 having a constitutional unit shown in Table 1 below, and a required amount of a solvent (toluene, xylene) are placed in a flask. Then, a softening point of 1 was obtained in the same manner as in Silicone Preparation Example 1 described above.
A silicone solid resin (silicone A-2) having a molecular weight (Mw) of 30,000 at 10 ° C was obtained.

(Silicone Preparation Example 3) A silane compound (chlorosilane, alkoxysilane) having a composition of silicone A-3 having a constitutional unit shown in Table 1 below and a required amount of a solvent (toluene, xylene) are placed in a flask. Then, a silicone solid resin (silicone A-3) having a softening point of 90 ° C. and a molecular weight (Mw) of 30,000 was obtained in the same manner as in the above silicone preparation examples 1 and 2.

(Silicone Preparation Example 4) Cyclic siloxane Octamethylcyclotetrasiloxane was placed in a flask,
A dehydration process is performed to remove water in D4. Next, while heating and stirring at a constant temperature, necessary amounts of a KOH catalyst and decamethyltetrasiloxane are added to carry out polymerization. Then, by adjusting the viscosity and adjusting the molecular weight by equilibration, a silicone oil (silicone A-4) having a molecular weight (Mw) of 50,000 was obtained.

[0021]

[Table 1]

Next, the adjustment of the filler will be described. (Filler Preparation Example 1) First, 100 g of wet silica having a specific surface area of 200 m ² / g having a silanol group is placed in a 100 g flask and brought into a fluid state under a nitrogen gas atmosphere. Next, 5 g of triphenylchlorosilane in a liquid state is dropped from the upper part of the flask and reacted. Then, after the reaction is completed, the contents of the flask are subjected to a dehydrochlorination treatment by heating (120 ° C.) to give a triphenylsilylated silica powder (filler B-1) 104 having a specific surface area of 200 m ² / g.
g was obtained.

(Filler Preparation Example 2) First, 100 g of wetland silica having a specific surface area of 200 m ² / g having a silanol group was used.
Put into a flask and make it flow under a nitrogen gas atmosphere.
Next, from the upper part of the flask, 5 g of trimethylchlorosilane in a liquid state is dropped and reacted. After the reaction was completed, 103 g of trimethylsilylated silica powder (filler B-2) having a specific surface area of 200 m ² / g was obtained in the same manner as in the above-mentioned filler preparation example 1.

(Filler Preparation Example 3) First, 100 g of wet silica having a specific surface area of 200 m ² / g having a silanol group is placed in a flask and brought into a fluid state under a nitrogen gas atmosphere.
From the upper part, 5 g of dimethylvinylchlorosilane in a liquid state is dropped, and the reaction is performed. After completion, a dimethylvinylsilylated silica powder (filler B-3) 103 having a specific surface area of 200 m ² / g was prepared in the same manner as in the above-mentioned filler preparation example 1.
g was obtained.

(Filler Preparation Example 4) 100 g of wet silica having a specific surface area of 130 m ² / g having a silanol group was placed in a flask, heated (120 ° C.), dried, and dehydrated to obtain a silanol having a specific surface area of 130 m ² / g. 99 g of group-containing silica powder (filler B-4) was obtained.

(Filler Preparation Example 5) 100 g of a wet silica having a specific surface area of 200 m ² / g having a silanol group was placed in a flask, and a silanol group-containing specific surface area of 200 m ² / g was prepared in the same manner as in Filler Preparation Example 4. 99 g of silica powder (filler B-5) was obtained. Table 2 below shows the surface-treated silica powder (filler B) obtained in the above-described filler preparation examples 1 to 5.
-1 to B-5).

[0027]

[Table 2]

Next, the silicone (A-1 to A-
4) Preparation of mixture of fillers (B-1 to B-5) will be described. (Preparation Example 1 of Mixture) 70 parts by weight of silicone (A-1) and 30 parts by weight of filler (B-1) are universally mixed. Put in the machine, 12
Melt kneading at 0 ° C., consisting of silicone + filler 1
00 parts by weight of a solid mixture (C-1) was obtained. (Mixture Preparation Example 2) 70% by weight of silicone (A-2) and 30 parts by weight of filler (B-2) were mixed with the above-mentioned mixture preparation example 1
Was kneaded in the same manner as in Example 1 to obtain 100 parts by weight of a solid mixture (C-2).

(Mixture Preparation Example 3) Silicone (A-3)
70 parts by weight and 30 parts by weight of the filler (B-3) were kneaded in the same manner as in the above-mentioned mixture preparation example 1, to obtain 100 parts by weight of a solid mixture (C-3). (Mixture Preparation Example 4) 70 parts by weight of silicone (A-4) and 30 parts by weight of filler (B-2) were kneaded in the same manner as in Mixture Preparation Example 1 described above, and a solid mixture of 100 parts by weight was obtained. (C-4) was obtained.

(Preparation Example 5 of Mixture) Silicone (A-1)
70 parts by weight of the filler (B-4) and 30 parts by weight of the filler (B-4) were placed in a universal mixer and heated and kneaded to obtain 100 parts by weight of a solid mixture (C-5). (Mixture Preparation Example 6) 70 parts by weight of silicone (A-2) and 30 parts by weight of filler (B-5) were kneaded in the same manner as in Mixture Preparation Example 1 described above, and a solid mixture of 100 parts by weight was obtained. (C-6) was obtained. (Mixture Preparation Example 7) 70 parts by weight of silicone (A-3) and 30 parts by weight of filler (B-5) were kneaded in the same manner as in Mixture Preparation Example 1 described above, and 100 parts by weight of a solid mixture was obtained. (C-7) was obtained.

(Mix Preparation Example 8) Silicone (A-4)
70 parts by weight and 30 parts by weight of the filler (B-4) were kneaded in the same manner as in the above-mentioned mixture preparation example 1, to obtain 100 parts by weight of a solid mixture (C-8). (Mixture Preparation Example 9) 70 parts by weight of silicone (A-4) and 30 parts by weight of filler (B-5) were kneaded in the same manner as in Mixture Preparation Example 1 described above, and 100 parts by weight of a solid mixture was obtained. (C-9) was obtained. Table 3 below shows the blending characteristics of the mixtures (C-1 to C-9) obtained in the above mixture preparation examples 1 to 9.

[0032]

[Table 3]

Next, adjustment of the flame-retardant resin composition in the examples of the present invention will be described. First, a mixture of silicone and a filler (silica powder) obtained as described above, and a bisphenol A-type polycarbonate resin (Gulliver 301-1 manufactured by Sumitomo Dow) used as a thermoplastic resin
0) was melt-kneaded with a stone mill type extruder. The kneading temperature at that time is 280 ° C. Next, after the melt-kneaded resin composition was dried at 120 ° C. for 3 hours, 3.2 × 1
A test piece having a size of 2.7 × 130 (mm) was formed by an injection method. The molding humidity is 300 ° C. and the molding time is 27 seconds. Then, the test piece molded by the injection method was evaluated for flame retardancy in accordance with the UL94V test (flammability test of plastic materials for equipment components) determined by Underwriters Laboratories. UL94V refers to a test piece of a predetermined size held vertically and a flame of a burner of 10 mm.
This is a method for evaluating flame retardancy based on the residual flame time after drip indirect flame and drip properties, and is classified into the classes shown in Table 4 below.

[0034]

[Table 4]

The afterflame time shown in Table 4 is the length of time after which the test piece continues to burn with flame after the ignition source is moved away. In addition, the ignition of the cotton by the drip is determined by whether the cotton located about 300 mm below the lower end of the test piece is ignited by a drip from the test piece,

The following Tables 5 to 7 show Example 1 of the present invention.
To 9, the amount of silicone and filler (silica powder) based on 100 parts by weight of the thermoplastic resin of each flame-retardant resin composition (test piece), and the kneading properties, afterflame time and drip properties of each resin composition Shows the test results. Table 5 below
7, the component A indicates a thermoplastic resin, and the component B
Is a filler or a mixture added to make the thermoplastic resin flame-retardant, and is shown in Tables 1 to 3.

[0037]

[Table 5]

[0038]

[Table 6]

[0039]

[Table 7]

In Tables 5 to 7, ○: good kneading (discharge stability), Δ: slight kneading problem (slight pulsation during discharge). The after-flame time indicates the total (seconds) of the after-flame time of the five samples. In the results of the drip properties, ○ indicates no drip, Δ indicates drip but no ignition to the labeling substance, and × indicates drip. Each of the figures indicates that the marker substance is ignited. The unit of the compounding amount is part by weight.

Examples 1 to 2 in Table 5 and Examples 3 to 6 in Table 6
5 and Comparative Examples 1 to 6 in Table 5, the composition comprising the mixture of the silicone and the filler (silica powder) of the example and the polycarbonate resin was the same as the polycarbonate alone of the comparative example (Comparative Example 6), , Silicone alone (Comparative Examples 1-2) and filler alone (Comparative Examples 3-2)
It can be seen that the drip property is improved and the flame retardancy is improved as compared with 5). In addition, it can be seen that the presence of the filler improves the kneadability of the silicone alone.

Table 7 shows the results of the surface treatment of the filler and the improvement of the flame retardancy by the structure of the silicone.
As can be seen from Table 7, when the surface of the silica powder as the filler was previously subjected to an alkylsilylation treatment and added (Example 6), when the silica powder without the surface treatment shown in Example 2 and the silicone component were added. It can be seen that the after-flame time can be shortened and the flame retardancy is further increased. Further, as shown in Examples 7 to 9, in addition to the features of Example 6, the terminal of the silicone added for flame retardation is further sealed with a trialkylsiloxy and is a unit represented by RSiO _1.5. In the case of containing, the flame-retardant resin composition shortens the after-flame time and does not cause dripping, indicating that the flame-retardant resin composition exhibits higher flame retardancy.

As described above, a flame-retardant resin composition comprising a polycarbonate resin to which a mixture of silicone and a filler has been added can improve the flame retardancy, especially the after-flame time and drip property in the UL test. Has the effect of improvement. In addition, since the flame retardancy has been improved compared to the conventional technology, it is possible to reduce the amount of components such as silicone and a filler,
The effects of improving the kneadability of low-molecular-weight silicone, reducing costs, and improving mechanical strength are obtained. Further, according to the flame-retardant resin composition of the present invention as described above, even if other flame retardants (for example, a halide, a combination of a halide and antimony oxide, or a phosphorus compound) are not used, the flame retardant resin composition can be used as described above. Can exhibit flame retardancy. In addition, the mixture of the silicone and the inorganic substance of the present invention can utilize the synergistic effect in combination with the flame retardant,
Since the flame retardancy of the flame-retardant resin composition of the present invention has been improved as compared with the related art, the amount of the mixture of the silicone and the inorganic substance and the other flame retardants can be significantly reduced.

[0044]

As described above, in the present invention, a mixture of silicone and an inorganic substance is added to a thermoplastic resin. Silica powder was used as the inorganic substance, and the surface of the silica powder was alkylsilylated. As a result, the flame-retardant resin composition of the present invention has an effect that a flame-retardant effect such as an effect of preventing drip can be improved without lowering the function as the resin composition.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 83:04) (72) Inventor Yasushi Iwabuchi 6-31, Roppongi, Minato-ku, Tokyo Toshiba Silicone Corporation (72) Inventor Takagi Akira Toshiba Silicone Co., Ltd. 2-3-1 Roppongi, Minato-ku, Tokyo

Claims (4)

[Claims] 1. A flame-retardant resin composition characterized in that a mixture of silicone and an inorganic substance is added to a thermoplastic resin. 2. The flame-retardant resin composition according to claim 1, wherein the inorganic substance is silica powder. 3. The flame-retardant resin composition according to claim 2, wherein the surface of the silica powder is alkylsilylated. 4. The resin composition according to claim 1, wherein the silicone is composed of a unit having a chemical formula represented by RSiO _1.5 , wherein R in the chemical formula is an alkyl group, an alkenyl group, A flame-retardant resin composition, which is a group comprising any one of aryl groups or a component obtained by combining them.