JPS5928343B2 - Flame retardant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flame retardant resin composition with improved thermal stability and mechanical strength.

More specifically, it is obtained by polymerizing styrene and acrylonitrile or methyl-ol methacrylate using a bulk suspension polymerization method in the presence of a diene rubber component.
Moreover, the graft copolymer (2
), a graft copolymer (2) obtained by polymerizing styrene and acrylonihelyl or methyl methacrylate under emulsion polymerization conditions in the presence of a diene rubber latex, and a vinyl chloride polymer (O and b) It relates to a flame-retardant resin composition that has excellent impact resistance, rigidity, heat resistance, etc., and has excellent thermal stability and moldability.

In recent years, plastic materials have been used in a wide variety of fields, and styrenic resins such as ABS resins are also used in a wide variety of fields as automobile parts, electrical appliances, construction materials, and various other molded products.

With the expansion of this usage, various regulations have arisen, and even the use of flame-retardant materials is simply required to have self-extinguishing properties! 5 Not only that, but regulations are also becoming stricter, such as preventing the occurrence of ``sparkling'' during combustion. There are two ways to make plastics flame retardant: one is to add flame retardants to plastics and blend them, and the other is to directly introduce flame retardant ingredients into plastics through copolymerization, etc., but the former is generally used the most. ing.

In particular, when ABS resin is blended with vinyl chloride resin, it tends to extinguish the fire without causing the above-mentioned "sparkling fire", and from the viewpoint of the low cost of the material, mixed resin compositions of ABS resin and vinyl chloride resin are interesting. Many technological developments are being carried out regarding this.

However, since the thermal decomposition temperature of the vinyl chloride resin is close to the molding temperature of the Caja BS resin, the molding processability of this mixed resin composition is extremely poor. In order to improve this shortcoming,
Attempts have been made to improve the fluidity of ABS resin, add plasticizers, and even incorporate heat stabilizers, but for example, in order to improve the fluidity of ABS resin, it is possible to mold it at a temperature close to that of vinyl chloride resin. If the molecular weight of the ABS resin is reduced to such a degree, the mechanical strength of the mixed resin composition will be so low that it will no longer be practical, and if a plasticizer is added, the heat resistance and rigidity will be significantly reduced. Although some improvement is brought about by adding a heat stabilizer, it is far from solving the problem of poor moldability, and the impact resistance, heat resistance, rigidity, etc. of the mixed composition of ABS resin and vinyl chloride resin are not improved. At present, no material has been obtained that has excellent mechanical properties, good thermal stability, and excellent moldability. In view of these circumstances, the present inventors have developed a material that is made of a graft copolymer such as ABS resin and a vinyl chloride resin, which has well-balanced mechanical properties, and has excellent thermal stability and moldability. The present invention was achieved as a result of intensive research aimed at providing a flammable resin composition.

That is, ABS resin is usually produced by emulsion grafting reaction of styrene and acrylonitrile onto diene rubber latex, but emulsifiers and salting-out agents are present in ABS resin produced by this emulsion polymerization method. remains in the resin, resulting in a decrease in the thermal stability and electrical properties of the resin.
When mixed with a vinyl chloride resin, the thermal stability of the mixed resin composition is further reduced.

On the other hand, ABS resin produced by the bulk suspension polymerization method does not contain the above-mentioned compounds and has good compatibility with vinyl chloride resin, and the thermal stability of this mixed resin composition depends on the emulsion polymerization method. This is significantly improved compared to the case where ABS resin produced in this way is used. However, in the ABS resin produced by the bulk suspension method, the shape of the rubber particles dispersed in the resin is larger than that of the ABS resin produced by the emulsion polymerization method.

Therefore, AB using bulk suspension polymerization method with large rubber particle size
Mixed resin compositions using S resins and vinyl chloride resins produce molded products with poor luster, have shortcomings in heat resistance, etc., and are difficult to obtain with high commercial value. However, by reducing the diameter of the dispersed rubber particles in the ABS resin produced by the bulk suspension polymerization method, these drawbacks can be sufficiently improved, and the excellent thermal stability obtained when using the ABS resin produced by the bulk suspension polymerization method is improved. A mixed resin composition with a vinyl chloride resin having a good balance of physical properties that can sufficiently exhibit the following properties can be obtained. On the other hand, in the bulk suspension polymerization method, polymerization is started from a state in which the rubber component is dissolved in a mixed vinyl monomer with styrene and acrylonitrile, so the amount of the rubber component to be used is restricted. Furthermore, as mentioned above, when making a mixed resin composition with a vinyl chloride resin, it is necessary to reduce the dispersed rubber particle size in the ABS resin, which ultimately tends to reduce the impact strength of the ABS resin. be. For this reason, mixed resin compositions with vinyl chloride resins may be subject to restrictions in terms of impact strength in their application to various uses. However, when an emulsion polymerization ABS resin, etc., which is not restricted by the amount of rubber used, is blended in a specific ratio into a mixed resin composition consisting of a bulk suspension polymerization ABS resin having a specific rubber particle size and a vinyl chloride resin, polymerization occurs. The synergistic effect of ABS resins produced by different methods provides excellent mechanical strength including impact strength, and flame retardancy with excellent thermal stability and moldability equivalent to when using only bulk suspension method ABS. It was discovered that a mixed resin composition of That is,
In the present invention, styrene and acrylonitrile or methyl methacrylate are first polymerized under bulk polymerization conditions in the presence of a diene rubber component, and then the polymerization is continued under suspension polymerization conditions to substantially complete the polymerization. The presence of graft copolymer 6, which is a graft copolymer obtained by Under,
A graft copolymer obtained by polymerizing styrene and acrylonitrile or methyl methacrylate under emulsion polymerization conditions, and vinyl chloride alone or a vinyl chloride polymer containing vinyl chloride as a main component (O). , the weight ratio of the graft copolymer (4) and (day) is 95:5 to 30:7.
0, and the total content of graft copolymer 6 and (9) is 35 to 65% by weight, and the content of vinyl chloride polymer (O) is 35 to 65% by weight. This is what we provide.

The diene rubber component used in the kraft copolymer (4) in the present invention includes butadiene and isoprene rubber, but among them, polybutadiene with relatively high stereoregularity using a lithium or organometallic compound catalyst, The butadiene-styrene copolymer spreads well. There is no particular limitation on the amount of the diene rubber component used, but generally 2 to 40 parts by weight of the rubber component is used per 100 parts by weight of vinyl monomers such as styrene and acrylonitrile. Average diameter of wide particles 0.7-0.
2 to 25 parts by weight is suitable because it is necessary to control the amount to 1μ. Next, in the case of styrene and acrylonitrile as vinyl monomers used in the graft copolymer (4), there is no particular limitation on the mixing ratio, but generally styrene is 80 to 55 parts by weight and acrylonitrile is 80 to 55 parts by weight. 20
About 45 parts by weight is suitable. Methyl methacrylate is used depending on the transparency of the mixed resin composition and other specific purposes, but the amount used is generally about 0 to 50% by weight based on the total vinyl monomer. Graft copolymer of the present invention (
There are no limitations on the bulk suspension polymerization conditions for producing 4), and a wide variety of commonly known conditions may be employed.

To control the average particle diameter of dispersed rubber particles, which is an important condition for Tamashi graft copolymer (4), adjustment of the stirring power in the bulk polymerization step, or molecular weight regulator,
When the average particle size is less than 0.1μ, the mechanical strength due to the synergistic effect with the graft copolymer (0) is not developed, while when it is more than 0.7μ, the final mixed resin composition is The molded product may lack luster and lack practicality.Next, the graft copolymer (B) in the present invention is produced by a conventional emulsion polymerization method.

In other words, the diene rubber latex is a latex of a homopolymer such as butadiene or isoprene, or a copolymer with a vinyl monomer such as styrene or acrylonitrile.There are no specific restrictions on the particle size or gel content of the latex, and it is usually A wide variety of materials can be used, such as those used for ABS resin. Next, there is no particular limitation on the usage ratio of styrene, acrylonitrile, or methyl methacrylate as the vinyl monomer used in the graft copolymer (B), but the general usage ratio is as follows: )
The same is true for . In addition, there are no restrictions on the amount of solid rubber components used in diene rubber latex, but
Generally, 2 to 1 parts by weight per 100 parts by weight of vinyl monomers.
Fifty parts by weight of the rubber component is used, with 10 to 100 parts by weight being preferred. There are no limitations on the emulsion polymerization conditions for producing the graft copolymer (Bl) from these diene rubber latexes and styrene and acrylonitrile or methyl methacrylate, and commonly known conditions can be widely adopted. Vinyl chloride polymer base 0 is a vinyl chloride homopolymer and a copolymer of vinyl chloride as a main component with ethylene, propylene, vinyl acetate, etc., and has an average degree of polymerization of 500 to 1000. Coalescing is preferred for the purposes of the present invention.

In the present invention, the flame-retardant resin mixture consisting of the graft copolymers (4) and (B) and the vinyl chloride polymer (O is 35
~65% by weight; if less than 35% by weight, the final resin mixture will have insufficient flame retardancy; if more than 65% by weight, the moldability of the resin mixture will be poor, and mechanical strength such as impact strength will be reduced. decreases and becomes impractical.

On the other hand, the mixing ratio with graft copolymer A (5(B) is (A
):8 is in a weight ratio of 95:5 to 30:70, and only within this range can the graft copolymer maintain the good thermal stability and moldability provided by the graft copolymer (4). A final resin composition with improved mechanical strength can be obtained by blending the resin composition. Particularly preferably (A): (0
The weight ratio is within the range of 90:10 to 50:50, and the features of the present invention are fully exhibited within this range. If the graft copolymer (4) is used in an amount greater than 95 parts by weight in the graft copolymer, the effect of blending the graft copolymer (13) will not be observed, and if it is less than 30 parts by weight, the final resin composition may not be as good. Thermal stability and moldability cannot be obtained. In the present invention, the graft copolymers (4) and (B) and the vinyl chloride polymer (O) can be mixed using a conventional mixing device such as a hot roll, a Banbury mixer, or a special method without requiring any special means or order. It can be easily manufactured using an extruder.

The flame-retardant resin composition of the present invention may contain various additives, such as commonly used heat stabilizers, antioxidants, lubricants, and colorants, if necessary.

In some cases, plasticizers, flame retardants, etc. may also be used as supplements within a range that does not impair the characteristics of the present invention. The diameter of the dispersed rubber particles in the graft copolymer (4) specified in the present invention is measured by taking an electron micrograph using an osmium staining method, and the longest diameter of the dispersed rubber particles is defined as a.
The average particle diameter r is determined by measuring at least 100 rubber particles and using the following formula, where b is the diameter passing through the center of a and intersecting at right angles to a.

Average particle diameter: 1 (,?, Niri)/(,?101) The present invention will be described in detail with reference to Examples below, and all parts in the examples are parts by weight. Example 1 65 parts of styrene, 35 parts of acrylonitrile, and styrene-butadiene rubber (“Tufden 2000A″″ manufactured by Asahi Kasei Corporation) 8
0.15 part of benzoyl peroxide in a solution consisting of
A composition containing 0.08 parts of dicumyl peroxide and 0.5 parts of tertiary decyl mercaptan was charged into a closed reaction vessel equipped with a strong stirring device, and bulk polymerization was carried out at 70°C for 4 hours under strong stirring. I did it.

Next, the above reaction mixture was transferred to another closed reaction vessel in which a dispersant suspension water consisting of 100 parts of water, 4 parts of magnesium hydroxide, and 0.05 parts of sodium laurate had been prepared in advance,
Stir to suspend. Thereafter, the temperature was raised to 120°C and polymerization was carried out for 5 hours. After the obtained polymer particles were cooled, a dispersant was dispersed in hydrochloric acid, washed with water, and then dried. This graft copolymer had an average rubber particle size of 0.4 μm. This graft copolymer will hereinafter be referred to as graft G-1.

135 parts of Graft G-1, 15 parts of ABS resin produced by emulsion polymerization method (JSR-35'' manufactured by Japan Synthetic Rubber Co., Ltd.) and vinyl chloride homopolymer (Vinitalon 4000 manufactured by Mitsui Toatsu Co., Ltd.) were added to 135 parts of Graft G-1.
50 parts of LL5' average polymerization degree (700), 2.5 parts of dibutyltin maleate, and 0.5 parts of α-olefin oxide are mixed in a pen shell mixer.

This mixture is designated as mixture A. A test piece of mixture A was molded using an extrusion molding machine, and the tensile strength (ASTMD-638
(According to the measurement of ), Izod impact strength (ASTM) -
256), heat distortion temperature (ASTMD-64
8) and flame resistance (according to the measurement of UL No. 94) were measured. The results are summarized in Table 1. As a coloring heat resistance test, a 14-ounce injection molding machine was used to determine the coloring change of a molded product (fabric weight 130 f, fountain pen case) at a molding temperature of 180 to 220°C.

The results are shown in Table 2. The coloring standards are as shown in Table 3.
5 indicates the least discoloration and 5 indicates the most discoloration.

From Tables 1 and 2, graft G-1 and A obtained by emulsion polymerization method
The mixture A11 of the present invention, which is a mixture of BS resin (JSR-35'') and vinyl chloride resin homopolymer, has flame resistance that is not impaired and mechanical and It is clear that it has excellent thermal properties and thermal stability during molding.

Example 2 This example shows the thermal stability effect when changing the mixing ratio of Graft G-1 in Example 1 and ABS resin (JSR-35'') produced by emulsion polymerization. be.

That is, 125 parts of Graft G-1, 25 parts of JSR-35'', 50 parts of Vinicron 4000LL'', 25 parts of dibutyltin maleate, and 0.5 part of α-olefin oxide are mixed in a pen shell mixer.This mixture is mixed as mixture B.
It is expressed as In this example, the method of Example 1 is used. The results of various physical properties and coloring heat resistance are shown in Tables 4 and 5, respectively. From Tables 4 and 5, although the mixing ratio of Graft G-1 was lowered, Mixture B did not impair thermal stability compared to vinyl chloride resin (''Viniclon 4000LL'') alone. It can be seen that the mechanical and thermal properties are excellent.

Comparative Example 1 This comparative example shows the thermal stability effect when the ABS resin (゜"JSR-35'゛) produced by the emulsion polymerization method in Example 1 is excluded.

That is, 150 parts of Graft G-1, 50 parts of vinyl chloride homopolymer (Vinicron 4000LL), 2.5 parts of dibutyltin maleate, and 0.5 parts of α-olefin oxide are mixed in a pen shell mixer. Mixture C
It is expressed as In this comparative example, the method of Example 1 is used.

The results of various physical properties and coloring heat resistance tests are shown in Tables 6 and 7, respectively. From Tables 6 and 7, it can be seen that the mixture C, which is a mixture of Graft G-1 and the vinyl chloride resin "Viniclon 4000LL"", has better mechanical, thermal properties, and coloring heat resistance than the vinyl chloride resin "Viniclon 4000LL"" alone. However, compared to the mixture A of the present invention containing ABS resin produced by emulsion polymerization method (JSR-35''),
It can be seen that the Izotsu impact strength is small.

Comparative Example 2 In this Comparative Example, instead of the graft G in Comparative Example 1, ABS resin ("JSR-") produced by emulsion polymerization was used.
35″″) is used.

゜゜50 parts of JSR-35'' and vinyl chloride homopolymer (
6゛Vinicron 4000LL'') 50 parts, dibutyltin maleate 2.5 parts, α-olefin oxide 0.5
2 parts using a pen shell mixer. 5 This mixture is designated as mixture D.

In this comparative example, the method of Example 1 is used.

The results of coloring heat resistance are shown in Table 8.

From Table 8, ABS resin produced by emulsion polymerization method (゛JSR-3
Mixture D in which 5゛) was mixed with vinyl chloride homopolymer is
It can be seen that the thermal stability is greatly reduced compared to Mixture A of the present invention.

Example 3 In this example, styrene-butadiene rubber (“Tufden 200” manufactured by Asahi Kasei Corporation) was used instead of graft G~1 in Example 1.
This figure shows the thermal stability effect when using a graft copolymer (hereinafter referred to as graft G-2) prepared under the same conditions except that 5 parts of 0A') were used.

The average rubber particle size of Graft G-2 is 0.3μ. As a graft copolymer produced by emulsion polymerization, MBAS (manufactured by Nippon Gosei Resin Co., Ltd., a four-component composition of styrene, acrylonitrile, methyl methacrylate, and butadiene rubber "JSR")
6O゛) is used. In addition, as the vinyl chloride resin, a vinyl chloride copolymer (manufactured by Nissan Chemical Co., Ltd., copolymer with ethylene, ゜"Nissan Vinyl E-650"'' average degree of polymerization 650) is used. 235 parts of Graft G- and ゜゛JSR- 60″
15 parts of Nitsusan Vinyl E-650'', 2.5 parts of dibutyltin maleate, and 0.5 parts of α-olefin oxide are mixed in a pen shell mixer. This mixture is referred to as mixture E. In this example, is Example 1
method is used.

The results of various physical properties and coloring heat resistance are shown in Tables 9 and 10, respectively.

From Tables 9 and 10, mixture E containing graft G-2 of the present invention is a mixture of vinyl chloride-ethylene copolymer (E-65
It is clear that the mechanical properties, thermal properties, and heat resistance of coloring are significantly superior to those obtained by using 0゛'') alone.

Example 4 In this example, instead of Graft G-1 in Example 1, 45 parts of styrene, 20 parts of acrylonitrile, and methylmethane were added to 10 parts of styrene-butadiene rubber (Tuffden 2000A, manufactured by Asahi Kasei Corporation). This figure shows the thermal stability and transparency effects when using a graft copolymer (hereinafter referred to as graft G-3) prepared under the same conditions except that 35 parts of acrylate was used.

The average rubber particle size of Graft G-3 is 0.5μ.

MBS (Kaneace B-11, a three-component graft copolymer consisting of butadiene rubber, styrene, and methyl methacrylate, manufactured by Kanebuchi Kagaku Co., Ltd.) is used as the graft copolymer produced by emulsion polymerization. 40 parts of Graft G-3, 15 parts of Kaneace Bll', 245 parts of '1 Nitsusan Vinyl E-650' and 2.5 parts of dibutyltin maleate.
1 part and 0.5 part of α-olefin oxide are mixed in a pen shell mixer.

This mixture is designated as mixture F. In this example,
The method of Example 1 is used. The results of metabolic properties and coloring heat resistance are shown in Tables 11 and 12.

The transparency in Table 11 is determined visually, and the thickness is 1/1.
A comparison was made using a 6″″ disc molded product. From Tables 11 and 12, it can be seen that the mixture F, which is a mixture of the graft G-3 of the present invention, has better mechanical, thermal properties, and coloring heat resistance than the vinyl chloride-ethylene monocopolymer (゜゛E-650'''') alone. It can be seen that the results are excellent and that transparency is not compromised.

Claims (1)

[Claims] 1. In the presence of a diene rubber component, styrene and acrylonitrile or methyl methacrylate are first polymerized under bulk polymerization conditions, and then polymerization is continued under suspension polymerization conditions to substantially complete the polymerization. In the presence of a graft copolymer (A), which is a graft copolymer having an average particle diameter of 0.7 to 0.1 μ of rubber dispersed in the graft copolymer, and a diene rubber latex. A graft copolymer (B) obtained by polymerizing styrene and acrylonitrile or methyl methacrylate under emulsion polymerization conditions, and vinyl chloride alone or vinyl chloride as a main component with an average polymerization degree of 500 to 1,000. Vinyl chloride polymer (
C), the graft copolymer (A): (B)
The weight ratio of the graft copolymers (A) and (B) is 95:5 to 30:70, and the total content of the graft copolymers (A) and (B) is 35 to 65.
Weight%, content of vinyl chloride polymer (C) is 35 to 65
% by weight of a flame-retardant resin composition.