JPH01236251A - Thermoplastic n-substituted maleimide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title resin composition improved in heat resistance and impact resistance, by mixing a specified resin composition with an ABS resin obtained by bulk/suspension polymerization. CONSTITUTION:A heat-resistant resin (A) is obtained by mixing 5-60wt.% random copolymer (a) comprising 20-65wt.% N-substituted maleimide (i) selected from among N-phenylmaleimide, N-cyclohexylmaleimide and N-(2,4,6- tribromo)phenylmaleimide and 35-80wt.% aromatic vinyl compound (ii) which is (alpha-methyl)styrene with 40-95wt.% random copolymer (b) comprising 50-82wt.% component (ii), 18-50wt.% vinylcyanide compound (iii) and 0-10wt.% vinyl monomers (iv) copolymerizable therewith. 40-70wt.% component A is mixed with a copolymer (B) obtained by grafting 20-50wt.% component (ii) and 55-20wt.% component (iii) onto 30-65wt.% rubbery polymer (v) to obtain a resin composition (I). 100pts.wt. component I is mixed with 5-20pts.wt. ABS resin (II) obtained by bulk-suspension polymerization.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a thermoplastic resin having excellent heat resistance and impact resistance.More specifically, the present invention relates to a thermoplastic resin composition containing an N-substituted maleimide. Regarding.

(Prior art and its problems) A commonly used method for improving the heat resistance of styrene-acrylonitrile copolymers is to replace part or all of styrene with α-methylstyrene. . In addition, rubber denaturation heat 1 represented by ABS i fat
lli]' In order to improve the heat resistance of plastic resin, a method of using α-methylstyrene as a part of the seven polymers to be grafted,
A method of blending ABS resin with so-called heat-resistant AS resin consisting of α-methylstyrene and acrylonitrile has been widely used.

These thermoplastic resins have higher heat resistance than ordinary ABS resins and are therefore used as interior materials for automobiles and office automation equipment, but their heat resistance is still insufficient. As a solution to this problem, many attempts have been made to increase the amount of α-methylstyrene in the resin, or to introduce anhydrous malein fff' as another component to improve heat resistance, but in either case, the thermal decomposition of the resin Due to insufficient stability, there was a limit to the improvement of heat resistance.

Attempts have also been made to improve the thermal decomposition stability of a copolymer consisting of an aromatic vinyl compound and maleic anhydride using a primary amine such as anisono. A composition with oil is disclosed in Japanese Patent Publication No. 62-8456. On the other hand, compositions of copolymer resins rich in N-substituted maleimides and ABS resins are also known, and are exemplified by JP-A-59-232138. However, in either case, the balance between heat resistance and impact resistance is poor, and for example, in order to increase heat resistance, N
- When a composite composition of a copolymer containing a large amount of substituted maleimide and ABS resin was obtained and its performance was evaluated, it was found that the impact resistance was insufficient. When a composite m-acid containing a large amount of ABS resin is obtained by reducing the amount of co-i coalesce, there is a problem that its heat resistance is not as high as that of conventional heat-resistant ABS (J resin).

The present inventor has added an effective additive to a thermoplastic resin, which is an N-substituted maleimide compound, that can improve the impact resistance without reducing the heat resistance of a blend composition with an ABS resin. In order to overcome the drawbacks of high heat resistance but low impact resistance that resins containing N-substituted imide compounds tend to have, we developed a copolymer of N-substituted maleimide and an aromatic ash vinyl compound. (A), copolymer of aromatic vinyl compound and vinyl cyanide compound (B) and AB
We have discovered that it is possible to obtain a new thermoplastic resin that maintains the high heat resistance characteristic of imide resins, improves its impact resistance, and has improved processability as well as S resin, and has developed the present invention. Reached.

(Means for Solving the Problems) That is, the present invention provides: (1) a random copolymer (A) comprising 20 to 65% by weight of an N-substituted maleimide and 35 to 80% by weight of an aromatic vinyl compound; Random copolymer consisting of 50 to 82% by weight of group vinyl compound, 18 to 50% by weight of vinyl cyanide compound, and 0 to 10M head of vinyl monomer copolymerizable with these (
Heat-resistant resin (1) made by mixing B) in a proportion of 5 to 60% by weight and CB) in a proportion of 40 to 95% by weight (1) 40 to 7
0% by weight, 20-503% by weight of vinylized aromatic flakes, 5-20% by weight of vinyl cyanide compound, 30-65% by weight of rubbery polymer.
An N-substituted maleimide-containing thermoplastic resin composition having excellent heat resistance and impact resistance, comprising 30 to 60% by weight, 20 parts by weight of a copolymer (■) obtained by graft polymerization with.

(2) N-[converted maleimide is N-phenylmaleimide, N-cyclohexynelumaleimide & N-(2,4,6
The N-substituted maleimide-containing thermoplastic resin assembly according to claim 1, wherein the N-substituted maleimide-containing thermoplastic resin fabric is at least one selected from the group consisting of -IJbromo)phenylmaleimide.

(3) The N- according to claim 1 or 2, wherein the aromatic vinyl compound is styrene, α-methylstyrene, or a mixture thereof.
Provides a substituted maleimide-containing thermoplastic resin composition. The N-f substituted maleimide, which is a copolymerization component in the random copolymer (5) used in the present invention, is preferably 20 to 65% by weight, particularly preferably It is used in a range of 40 to 65% by weight. 2
If the amount is less than 0M, the heat resistance of the random copolymer (A) 7 is low, so that the heat resistance of the final composition is also low. On the other hand, 65
If the amount exceeds % by weight, the melt flowability and thermal decomposition stability of not only the copolymer but also the final composition deteriorate. 40-65% by weight
Within this range, the final composition will have a good balance of physical properties such as heat resistance, impact resistance, and fluidity.

The aromatic vinyl compound of the random copolymer is 35 to 8.
0% by weight, preferably 35-60% by weight. If the amount of the aromatic vinyl compound is less than 35% by weight, the fluidity will decrease, and if it exceeds 80% by weight, the heat resistance will decrease, which is not preferable.

The random copolymer (A) is produced, for example, by solution polymerization, and in the superposition method of 7, for example, an aromatic vinyl compound and N
- Substituted maleimide is charged into a reaction vessel all at once and then polymerized, or after the aromatic vinyl compound and a small amount of N-substituted maleimide are charged, the remaining N-substituted maleimide is continuously added during polymerization. Any method is possible, such as adding and polymerizing. As the polymerization initiator used at this time, a radical initiator such as solauroyl peroxide can be used, and as the solvent, toluene, methyl ethyl ketone or chloroform can be used. Of these, methyl ethyl ketone (MEK) is particularly preferred. Polymerization temperature is 70-120
The temperature can be arbitrarily selected within the range of 0.degree. C., but a high temperature of 100.degree. C. or higher is desirable to increase the polymerization rate, and a low temperature of 70 to 80.degree. C. is desirable to increase the degree of polymerization.

Examples of the aromatic vinyl compound used in the random copolymer (4) include styrene, α-methylstyrene, and p-methylstyrene. Among these, it is particularly preferable to use styrene and α-methylstyrene alone or as a mixture thereof.

Examples of the N-substituted maleimide used in the random copolymer include N-7enylmaleimide, N-cyclohexylmaleimide, and N-(2,4,6-dolipromo)-phenylmaleimide.

The solution viscosity [η] of the random copolymer (g) is preferably 0.3 to 1.0 te measured in tetrahydrofuran at 30°C. If it is less than 0.3, the copolymer composition (
1) The impact resistance decreases. When [η] is 1.0 or more, the melt fluidity of (1) decreases, which is not preferable.

The aromatic vinyl compound, which is a copolymerization component of the random copolymer CB) conveniently used in the present invention, accounts for 50 to 82% by weight, preferably 65 to 82% by weight, and the vinyl/an compound accounts for 18 to 50% by weight. %, preferably 18 to 35% by weight of V″i, and 0 to 10% by weight of other copolymerizable vinyl monomers. It's not more than 1.

As the aromatic vinyl compound used for the random copolymer (B) in the present invention, the same compound as used for the random copolymer can be used. Further, as the vinyl cyanide compound, acrylonitrile, methacrylonitrile, etc. can be used, but acrylonitrile is most preferred. Copolymerizable navinyl monomers include acrylic esters such as methyl acrylate, ethyl acrylate, and methacrylic esters such as methyl methacrylate and ethyl methacrylate.

Random copolymer (4)
Alternatively, a suspension polymerization method can be used. In the case of the suspension polymerization method, a mixture of an aromatic vinyl compound and a vinyl cyanide compound is added to an aqueous solution containing a calcium phosphate dispersant to form a suspension, and the mixture is prepared under a nitrogen atmosphere/diyl di-oxide. The random copolymer (B) can be obtained in the form of beads by polymerizing at 75 to 90°C for about 10 hours using a radical initiator such as the following as a polymerization catalyst.

Bead-shaped polymers are particularly effective because they are easy to mix with the random copolymer powder.

The solution viscosity [η] of the random copolymer (B) is preferably 0.5 to 1.5 when measured under the same conditions as the random copolymer (A). If [η] is 0.5 or less, the impact resistance of the resin composition (1) blended with (5) will be low and the impact resistance of the final composition will also be low. If [η] exceeds 1.5, the fluidity becomes low, which is not preferable. 1 copolymerizable vinyl monomer
If it is used in an amount of 0% by weight or more, the heat resistance of the random copolymer (B) will deteriorate, which is not preferable.

The composition ratio of the random copolymer and the random copolymer (B) constituting the copolymer composition (1) is preferably 5 to 60% by weight. If (A) is less than 5% by weight, the heat resistance of the final composition will be impaired, and conversely, if (A) exceeds 60% by weight, the fluidity and thermal decomposition stability of the final composition will decrease, which is undesirable. The copolymer (II) used in this invention is obtained by graft polymerizing 20 to 50 liters of an aromatic vinyl compound and 5 to 20% by weight of a vinylphane compound to 30 to 65% by weight of a rubbery polymer. If the mixing ratio of the monomer mixture to be graft-polymerized is outside this range, the blendability with copolymer composition (I) will be poor, and the physical properties of the final composition, particularly impact resistance, will be poor. If the rubbery polymer is less than 30% by weight, the impact resistance of the copolymer is low, and the impact resistance of the final composition is similarly low. However, the heat resistance and melt fluidity will be lower.

As the aromatic vinyl compound and vinyl cyanide compound of the copolymer ([), the same monomers as those for the random copolymer (4) described above can be used. As the polymer, polyptazoene rubber, styrene-butanoene rubber, acrylic rubber, ethylene-propylene rubber, etc. can be used.

The copolymer ω) can be produced by a known emulsion polymerization method or solution polymerization method, but in order to obtain a spacing copolymer with a rubbery functional content, the above monomer mixture is added to a rubbery polymer latex. An emulsion polymerization method for grafting is advantageous.

The ABS resin produced by bulk suspension polymerization method q, which is an important component of the present invention, is a polymerization process in which a monomer mixture consisting of styrene and acrylonitrile is graft-polymerized in the presence of a polymer in the form of a polymer. In this case, a bulk suspension polymerization method is used to form a salami-like rubbery polymer phase, a styrene-acrylonitrile copolymer phase trapped therein,
and a styrene-acrylonitrile copolymer phase forming a continuous phase.

Among the rubbery polymers mentioned above, styrene-butadiene copolymer rubber is particularly preferred. ABS
The amount of rubbery polymer a in (11) is preferably 5 to 30% by weight. If it is less than 5% by weight, the effect of improving impact resistance is poor, and if it exceeds 30% by weight, the effect of improving fluidity during molding is poor.

The amount of ABS ([1) to be added to obtain the composition of the present invention is preferably 5 to 20 parts by weight per 100 parts by weight of the total amount of (1) + (II). If it is less than 5 parts by weight, the effect of improving both impact resistance and melt flowability is poor, and if it is used in excess of 20 parts by weight, the heat resistance of the final composition will decrease.

The composition ratio of (1) + ([1) in 100 parts by weight is preferably 40 to 70% by weight. (1) is 4
If it is less than 0% by weight, the heat resistance will be low, and if it exceeds 70% by weight, the impact resistance of the final composition will be reduced.

The mixing method for obtaining the composition of the present invention can be carried out by any method, for example, the product is produced by kneading with a Banbury mixer, a roll, a single screw or twin screw extruder, etc.

The composition of the present invention also has antioxidant properties during or after kneading.
Various additives such as inhibitors, heat stabilizers, and ultraviolet absorbers, reinforcing agents such as glass fibers and metal fibers, and fillers can also be mixed.

(Example) The present invention will be specifically described below using Examples. Unless otherwise specified, parts or percentages are based on weight. [Production of copolymer] The inside of a reactor equipped with a stirrer is replaced with nitrogen, and MEK
・100 parts, α-methylstyrene (αMe St
)・60 parts, N-phenylmaleimide (pMI)・
5 parts and polymerization initiator lauroyl peroxide (LPO
)・0.2 parts were added all at once. Without flowing a small amount of nitrogen, the temperature was increased using a heating medium from outside. Polymerization was started when the internal temperature reached 75°C, and polymerization was carried out at that temperature for 3.5 hours. During the polymerization, 35 parts of pMI was additionally added at a rate of 10 parts per hour. After the polymerization was completed, the inside was rapidly cooled, and the dope was transferred to a stainless steel container and degassed in a vacuum dryer. The degassed block sample was pulverized using a pulverizer. When this powder sample was analyzed with an IR vector, it was found that (IM
It was found that the eSL was 58chi and the pMI was 42%. Also, under measurement at 30°C in THF [v, l are 0.50
Met. Table 1 shows the results of a similar experiment with different types and amounts of monomers.

Table-1 Types of copolymers (A) *1) Methyl methacrylate *2) Cyclohexylmaleimide *3) N-(2,4,6-)libromo)phenylmaleimide [Production of co-electropolymer (B) ] The inside of the reactor equipped with a stirrer was replaced with nitrogen, and St.
72 parts, 28 parts of acrylonitrile (An) and benzoyl/? as a polymerization initiator. -Oxide (BPO) 0.3
A mixture of 5 parts and 0.18 parts of tertiary dodecyl mercaptan (TDM) as a molecular weight regulator was added and stirred well. Then, calcium phosphate dispersant, 0.2
and sodium dodecyl sulfate as a dispersion stabilizing agent.
100 parts of an aqueous dispersion of 1 part was added to the above monomer mixture and mixed at high speed to form a suspension. Raise the internal temperature to 75°C and start polymerization.

After maintaining this temperature for 6 hours, the internal temperature was further raised to 85° C. and the mixing was continued for 2 hours. After the dispersant was decomposed with hydrochloric acid, it was filtered, washed with water, and dried to obtain bead-shaped polymers having a particle size of about 0.2 mm. The yield was 98. The contents of [copolymer (B)] with a different polymer composition produced in the same manner are shown in Cloth-2.

Table 2 Types of copolymers (B) [Copolymers/■] The copolymers shown in Table 3 were the resins shown in Table 3 (manufactured by Japan Synthetic Rubber Co., Ltd.). Type of polymer (1) [Manufacture of ABS resin (g) by bulk suspension polymerization] The bulk suspension polymerization ABS resin in the present invention was manufactured as follows. 15 parts of styrene-butadiene copolymer rubber, 72% by weight of styrene and 28% by weight of azily latrile.
Furthermore, 0.35 parts of penzoylnose oxide (BPO) as an initiator and tertiary dodecyl mercaptan (TD) as a molecular weight regulator were dissolved in 85 parts of a monomer mixture of
M) Add 0.18 parts of the mixture and heat under nitrogen atmosphere at 75°C for 3 hours without stirring to cause complete bulk polymerization.
Friends. Then, 3 parts of magnesium hydroxide and 0.9 parts of Monokene (Daiichi Kogyo Seiyaku Co., Ltd., layer surfactant) were added as a dispersant.
The above polymerization solution and 0.2 parts of dicumyl peroxide (CPO) were added to 115 parts of the aqueous solution containing 1 part of CPO, and stirred at high speed to form a suspension in a nitrogen atmosphere.
Suspension polymerization was carried out by heating at 0° C. for 6.5 hours.

After cooling, the dispersant was decomposed with dilute hydrochloric acid, washed with water and dried to obtain resin beads grafted with hestyrene/acrylonitrile, a styrene-butatsuene copolymer rubber, having a particle size of about 0.3 base.

Table-4 Composition of ABS resin (2) [Method for evaluating physical properties] The physical properties were evaluated using the items in Table 5 below.

Table 5 [Example 1] Tri-blend 30 parts of copolymer (A-1) and 30 parts of copolymer (B-1) shown in the production example in polyethylene in powder and bead form. Then, the copolymer (if
-1>・40 parts and 10 parts of ABS by bulk suspension polymerization
After each part was weighed, 0.22 parts of Irganox 1010 (manufactured by Teva Geigy) was added as a heat stabilizer, and the mixture was thoroughly triblended in powder form.

In this composition, (A-1)/(B-1)=50150 and (1)/(1+11)=60/100. In addition, ABS-V (Ijuku == 10/, 100.
Supplied to Ill vent extruder, cylinder temperature 240
Kneading and extrusion were performed at a screw rotation speed of 3 Q rpm. Next, molded specimens for physical property evaluation were obtained using an injection molding machine manufactured by Konoha Rento and Yasei Jyushi Kogyo Co., Ltd.

Physical property evaluation JA mentioned in the previous section once evaluated all the molded specimens, and found that HDT = 116°C, l5 = 16 to 9 degrees, MFR = 1.69710 minutes, and heat resistance, impact resistance, melt flow. The properties were well balanced, and the molded specimen had a good appearance with almost no coloring.

[Example 2] [Example 1] was carried out in exactly the same manner except that copolymer (A-2, 1) containing a total amount of styrene was used in place of copolymer (A-1) in the same amount. The composition ratio of this yarn was (A
-2)/(B-1)=50150, (In/(1+l1
) = 7 equivalent to 60/100, ABS-IIID/(1
+u) = 10/100. Table 6 shows the results of evaluating the injection molded product of the obtained composition pellet. This composition also had excellent physical properties.

[Example 3] In [Example 1], this is an example using copolymer (A-3) obtained by copolymerizing copolymer (A-1) with 7-chlorohexylmaleimide. In this example, (A-3)/(B-1)=50
150, which corresponds to (1)/(1+II) = 40/100. It was carried out in the same manner as [Example 1]. Molded specimen υ
As shown in Table 6, the physical property evaluation results showed high heat resistance and impact resistance, and good fluidity.

[Example 4] Instead of the copolymer (A-1) of [Example 1], N
-(2,4,6-tribromo]phenylmaleimide copolymer (A-4) There are many examples using k.

The composition ratio is exactly the same as [Example 1]. Table 6 shows the results of evaluating the physical properties of injection molded products of this composition. Although this example had slightly lower impact resistance than the previous example, it had very high heat resistance.

[Example 5] In [Example 2], 10 to 15 parts of ABS'-(III) by bulk suspension polymerization was added to I+n=100 parts.
This is an example of increasing the number of units. The evaluation results in this case are as shown in Table 6, although the heat resistance is slightly lower than the previous example, the impact resistance is further improved and the physical properties are excellent.

[Comparative Example 1] This example is an example in which ABS obtained by bulk suspension polymerization was not added to [Example 1]. In this case, (A-1
)/(B-1)=50150, (1)/(1+■)
=60/100 r 6ru. As a result of kneading and extruding this composition and evaluating its physical properties, as shown in Table 6, the molded product had high heat resistance but low impact resistance, and was not satisfactory in terms of physical properties.

[Comparative Example 2] In this example, in [Example 1], copolymer (B-1)
Instead, a copolymer (B-2) outside the scope of the present invention was used, and the total number of copolymers was nine. The composition ratio of the component resins is as shown in [Example 1]
However, since (B-2) has poor compatibility with ABS resin, the impact resistance of the resulting composition was low as shown in Table 6.

[Comparative Example 3] This is an example in which (1-2), which is outside the scope of the invention, was used as the copolymer (11) in [Example 2].

The composition ratio is the same as [Example 2], but (II-2)
Because the rubber content was low, the impact resistance of the final composition was also low as shown in Table 6.

[Example 6] In this example, as shown in Table-7, 36 parts of (A-2) and (B-
29 copies of 1), 35 copies of (11-1), (MBs-1)
This is an example in which 10 copies of each were used. In this case (A-2)
/CB-g=55/45, (1)/(1+u)=6
5/100, and (1+l+)=A for 100 copies
BS-(g)=corresponds to 10 copies. As shown in Table 7, the physical properties of the molded specimen of this composition were high in heat resistance and impact resistance.

[Example 7] In this example, (A-4) 30 parts, (B-1) 25 parts, (
(A-4)/'(B-1) with a composition consisting of 45 parts of It-1) and 8 parts of a modifier (ABS-III).
= 55/45, (1)/(1+ll) =
It is 55/100. In this case as well, as shown in Table 7, the heat resistance was slightly lower than that of [Example 4], but the impact resistance was excellent.

[Example 8] An example in which a third monomer and methyl methacrylate were introduced into copolymer (5) and fc (A-5) was used in the same manner as [Example 3]. It is. This example (A-5
)/(B-1)=50150, (IL/ll+l1)
=6o/lo.

It is. The results of evaluating the physical properties of this composition are shown in Table 7, and it was found that heat resistance, impact resistance, and melt fluidity were well balanced.

[Comparative Example 4] An unusual example is an example in which the type of copolymer was the same as in [Example 2], but the composition ratio was outside the range. In this case, (A-2)/(B-1) = 50/50, but (B'(1+1) = 30/100. The physical properties of the composition at this time are shown in Table 7. Although the impact resistance was high, the heat resistance was low and the melt flowability was also low.

[Comparative Example 5] In this example, (A-2)/CB-1) = 50150, but (1)/(1+n) = 90/100, and it was carried out outside the scope of the present invention and there were 9 . Table 7 shows the physical property evaluation results in this case.
Although the heat resistance was very high, the impact resistance was low.

[Comparative Example 6] In this example, the type of copolymer was the same as in [Example 1], but 30 parts of the modifier (ABS-III) was used, which was outside the range. As shown in Table 7, the heat resistance was as low as 97C.

(Effects of the Invention) As a result of the present invention, the problem of high heat resistance but low impact resistance, which is common to conventional imide-modified styrenic resins, has been solved, and melt fluidity has also been improved. Therefore, it is possible to supply new resin materials that have the characteristics of styrene resins, such as excellent heat resistance and impact resistance, good moldability, and low cost, as chassis parts for OA equipment and automobile interior materials. I'm sorry.

Claims (3)

[Claims] (1) Random copolymer (A) consisting of 20-65% by weight of N-substituted maleimide and 35-80% by weight of aromatic vinyl compound, 50-82% by weight of aromatic vinyl compound, and 18-50% by weight of vinyl cyanide compound. %, and a random copolymer consisting of 0 to 10% by weight of a vinyl monomer copolymerizable with these (
B) in terms of weight, (A) 5 to 60% by weight, (B) 40 to 9
Heat-resistant resin (I) 40 mixed at a ratio of 5% by weight
~70% by weight, 20-50% by weight of aromatic vinyl compounds, 5-20% by weight of vinyl cyanide compounds, and 30-65% by weight of rubbery polymers.
ABS resin (III) produced by bulk suspension polymerization 5 to 100 parts by weight of a resin composition consisting of 30 to 60% by weight of copolymer (II) obtained by graft polymerization to
20 parts by weight of an N-substituted maleimide-containing thermoplastic resin composition having excellent heat resistance and impact resistance. (2) N-substituted maleimides include N-phenylmaleimide, N-cyclohexyl-maleimide and N-(2,4,
The N-substituted maleimide-containing thermoplastic resin composition according to claim 1, which is at least one selected from 6-tribromo)phenylmaleimide. (3) The N-substituted maleimide-containing thermoplastic resin composition according to claim 1 or 2, wherein the aromatic vinyl compound is styrene, α-methylstyrene, or a mixture thereof.