JPH0367109B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly impact resistant thermoplastic resin composition having a high heat distortion temperature. Copolymer resins comprising vinyl aromatic monomers and unsaturated dicarboxylic anhydrides (for example, styrene maleic anhydride copolymer resins) are known. This resin is useful because it has excellent processability, high strength and hardness as a resin, and sufficient transparency.In particular, because of its high heat deformation resistance, it is a styrene-acrylonitrile copolymer resin (hereinafter abbreviated as SAN resin). ) is suitable for use in more severe thermal conditions. However, the toughness of this resin, that is, its low impact strength, naturally limits its wide range of applications. On the other hand, by radical polymerization in the presence of polybutadiene or styrene-butadiene copolymer, a vinyl aromatic monomer (e.g. styrene) and an unsaturated nitrile compound (e.g. acrylonitrile) or (meth)acrylic acid ester (e.g. methacrylic acid) are combined. So-called ABS resins or MBS resins obtained by graft copolymerization of mixtures of (methyl) are also known. This is a so-called rubber graft copolymer resin in which grafted or ungrafted rubber is finely dispersed in a matrix resin such as a styrene-acrylonitrile copolymer resin or a styrene-methyl methacrylate copolymer resin. Because it has much higher impact resistance than styrene-maleic anhydride copolymer resin,
It has a wide range of uses such as parts for home appliances and automobiles, but on the other hand, its heat deformation resistance is insufficient, for example, about 80
In an atmosphere with a temperature higher than ℃, the product may deform during use or
As a result of changes in quality, there are limits to its application. A composite composition of styrene-maleic anhydride copolymer resin (A) and so-called ABS resin (B) is
This composition is disclosed in Japanese Patent No. 50775.
It is stated that it is possible to provide a thermoplastic composite resin molding material that has improved impact resistance and heat deformation resistance that cannot be expected from either (A) or (B) alone. Certainly (A) and (B)
By combining the two, it is possible to slightly improve the heat resistance and impact resistance of the resin in a way that complements the shortcomings of both.
Sci., B(3) , 1007 (1965) states that combinations of thermoplastic copolymer resins are usually incompatible, and compatible combinations are rather an exception. As expected from the fact that (A) and (B) are simply combined together, the physical properties of the composite resin composition cannot be said to be practically sufficient, and the composite resin The melt flow behavior, which is an indicator of the moldability of the composition, is also unsatisfactory. The present inventors have developed a vinyl aromatic monomer-unsaturated dicarboxylic anhydride copolymer resin (A) and a rubber-grafted vinyl aromatic monomer-unsaturated nitrile (or (meth)acrylic acid ester) monomer. In the process of studying in detail how to improve the physical properties of the composite resin composition of body copolymer resin (B), we added rubber-grafted vinyl, which has mutual affinity with each of the above-mentioned resins, as a physical property improver to this composite resin composition. Adding an aromatic monomer-unsaturated dicarboxylic anhydride (and, if necessary, an unsaturated nitrile monomer or methacrylic acid ester monomer copolymerizable with these) copolymer resin (C). Due to this, the composite resin composition has practically excellent heat deformation resistance,
The present invention was completed based on the surprising fact that the composite resin composition exhibits impact resistance and has better moldability than the composite component resin (B). That is, the present invention provides (A) a vinyl aromatic monomer of 65 to 95% based on the weight of the polymer;
30 to 35 parts by weight of a copolymer resin consisting of 10 to 35 parts by weight of an unsaturated dicarboxylic anhydride and, if necessary, 0 to 30 parts by weight of a vinyl monomer copolymerizable with these.
70% by weight (B) Vinyl aromatic monomer and unsaturated nitrile in the presence of 15 to 70 parts by weight of a rubbery polymer consisting of polybutadiene and/or styrene-butadiene copolymer, based on the weight of the polymer composition. Monomer or mixture of (meth)acrylic acid ester monomers30
20-70% by weight of a graft copolymer resin obtained by graft copolymerizing ~85 parts by weight and (C) 5-50% by weight of a rubbery polymer consisting of polybutadiene and/or styrene-butadiene copolymer, based on the weight of the polymer composition. 50 to 95 parts by weight of a mixture of a vinyl aromatic monomer, an unsaturated carboxylic acid anhydride, and optionally an unsaturated nitrile monomer or methacrylic acid ester monomer copolymerizable therewith, in the presence of 50 to 95 parts by weight. A heat-resistant/impact-resistant composite resin composition comprising 5 to 40% by weight of a graft copolymer resin obtained by graft copolymerizing the above-mentioned Thus, the object of the present invention is to provide a new resin composition that is easy to mold and has practically high heat resistance and impact resistance. A typical example of the copolymer resin (A) is a styrene-maleic anhydride copolymer. The content of unsaturated dicarboxylic anhydride in this copolymer resin is 10~
The range of 35% by weight is good, and considering the heat resistance and moldability of the composite, it is more preferably 10 to 25% by weight.
It is. It is preferable to copolymerize a third copolymerizable vinyl monomer in order to increase the affinity with the partner resin to be composited. For example, when ABS resin is selected as the graft copolymer resin (B), the convenient third monomer is acrylonitrile, and when MBS resin is selected as the graft copolymer resin (B), the third monomer is Methyl methacrylate is preferred. However, it is desirable that the total amount of the third monomer selected does not exceed 30% by weight in the copolymer. Polymerization of the copolymer resin (A) can be carried out by various methods and conditions, but it can be carried out by any of the known methods such as solution polymerization, precipitation polymerization, batchwise or continuous bulk polymerization. As a specific example, the temperature is 80 to 140
By thermal initiation at °C or by addition of a radical initiator,
A mixture of a vinyl aromatic monomer and an unsaturated dicarboxylic acid anhydride is polymerized by radical polymerization. In this case, when the combination of the monomers is styrene-maleic anhydride, since it has strong alternating copolymerizability, it is necessary to suppress the copolymer resin composition within the above composition range and to adjust the composition as the polymerization rate changes. In order to minimize compositional changes, a delicate monomer addition technique is required; an example of this can be found in the method previously proposed by the present inventors, that is, in JP-A-58-2313. I can do it. Incidentally, the copolymer resin (A) is effective in improving the heat deformation resistance of the resin composition of the present invention, but the content ratio in the composition is preferably 30 to 70% by weight, which is more practical. is the heat resistance of the composite resin composition,
In order to maintain melt fluidity at a high level value, it is desirable that the amount is 40% by weight or more in the composite resin composition, and on the other hand, in order to make the impact resistance of the composition a high value, it is preferably 65% by weight.
It is useful to limit yourself to: Examples of the vinyl aromatic monomer for the copolymer resin (A) include styrene, α-methylstyrene, nuclear-substituted halogenated styrene, and indene. Maleic anhydride is the most common example of unsaturated dicarboxylic anhydride, but chloromaleic anhydride, aconitic anhydride, citraconic anhydride, etc. may also be added as partial substitutes for maleic anhydride. It is possible. Typical graft copolymer resins (B) are
ABS resin or MBS resin. ABS resin or
MBS resins are usually mixtures of ungrafted rubbery polymers, rubber graft copolymers and styrene-acrylonitrile or styrene-methyl methacrylate copolymers as matrix-forming hard resins, the rubber content in the mixture being The total amount of ungrafted rubber is preferably in the range of 15 to 70% by weight, and in particular, in order to maintain the impact resistance of the composite resin composition of the present invention at a high level, the graft copolymer resin (B) contains 15 to 70% by weight. It is desirable to keep it at a level of 60% by weight.
The higher the content of the rubbery polymer, the higher the content of the rubbery polymer in the final composition, and the higher the impact resistance of the final composite composition. If the content is too high, during the kneading or molding process, the properties of the rubbery polymers will change due to mutual crosslinking, resulting in a marked decrease in melt flow or coloring, which will actually deteriorate the physical properties of the final composition. . Examples of the component forming the matrix resin, that is, the vinyl aromatic monomer, include the above-mentioned styrene, α
-Methystyrene, nuclear-substituted styrene, etc., preferably styrene and/or α-methylstyrene. Examples of other monomers forming the matrix resin, i.e., unsaturated nitrile compounds or (meth)acrylic esters, include acrylonitrile, methacrylonitrile, crotononitrile, methyl methacrylate, methyl acrylate, ethyl methacrylate, etc. The monomers can be selected from the following monomer groups, with a more specific example being acrylonitrile or methyl methacrylate. The total amount of the combination of the vinyl aromatic monomer constituting the matrix resin and the monomer copolymerizable with it is preferably 30 to 85% by weight in the graft copolymer resin (B), more preferably 40 to 85% by weight. ~85% by weight. In addition, it is desirable that the ratio of this combination is such that vinyl aromatic monomers such as styrene account for the majority;
Specifically, 50% of vinyl aromatic monomers such as styrene
It is best to keep it at ~95% by weight. The graft copolymer resin (B) is polymerized by a conventional known method, that is, using heat or a radical initiator at a temperature of 50 to
A method in which a rubbery polymer is dissolved in a monomer mixture as a matrix-forming resin component at 140°C and then polymerized in bulk, or a rubbery polymer latex is monomerized in an aqueous system in the presence of an emulsifier. Polymerization can be carried out by any method such as an emulsion polymerization method in which a mixture is added and polymerized, or a so-called bulk suspension polymerization method. However, as mentioned above, in order to maintain a high content of the rubbery polymer in the resin component (B), emulsion polymerization is more preferable. Next, regarding the composite physical property improver, that is, the graft copolymer resin (C), which plays an important role in the present invention, the polymer design described below is required, and for this purpose, the rubber graft vinyl aromatic monomer-unsaturated The polymerization of dicarboxylic anhydride copolymer resin (C) was investigated in detail. The main factors in designing this graft copolymer resin (C) are from the literature Minoura, Mori, Koka,
61, 109 (1958), the most important factors are the type of rubbery polymer, the selection of the type of resin to be grafted onto the rubbery polymer (to form a matrix phase), and the grafting ratio. There is no major problem in selecting from known polybutadiene or styrene-butadiene copolymers. However, in the latter case, when a styrene-butadiene random copolymer or a block copolymer in which styrene accounts for the majority is selected, some difficulty arises in controlling the grafting rate, which will be described later. The selection of the branched polymer of the present resin (C) can be considered as follows. That is, the matrix resin phase (continuous phase) of the final composite composition is formed by a highly polar vinyl aromatic monomer-unsaturated nitrile monomer or a vinyl aromatic monomer-unsaturated dicarboxylic anhydride. Since it is a composite of a copolymer of monomers, it is necessary to maintain a high level of heat resistance of the composite system, so in the end, the combination of vinyl aromatic monomer and unsaturated dicarboxylic acid anhydride monomer is I chose a combination. As is clear from the above-mentioned literature, the grafting ratio of the graft copolymer resin depends on many factors such as graft copolymerization conditions, the concentration of the radical initiator, and the concentration of the monomer to be grafted. Numerous graft copolymerization experiments were carried out to complete the present invention, and as a result of detailed studies, the following facts were found, which were useful in the subsequent structural design of the graft copolymer as an agent for improving the physical properties of composite systems. That is, a polydiene compound or a vinyl aromatic monomer-aliphatic diene compound copolymer is used as the rubbery polymer to be grafted (hereinafter referred to as the "trunk polymer"), and as a graft copolymer resin component (hereinafter referred to as the "branch polymer"). , when using a combination of vinyl aromatic monomer and unsaturated dicarboxylic acid anhydride, (a) In thermally initiated radical graft copolymerization at a polymerization temperature of 100 to 130°C, a grafting rate of about 20 to 80% by weight can be obtained under bulk polymerization conditions. is achieved. (b) When the initial charge amount of unsaturated dicarboxylic anhydride as a branched polymer component is increased, the polymerization rate increases and the grafting rate also increases. In this case, the content of unsaturated dicarboxylic acid anhydride in the branched polymer naturally also increases. If a molecular weight modifier (eg tertiarydecyl mercaptan) is used under high conditions, the grafting rate will decrease. On the other hand, when a radical initiator is added, the grafting rate is improved. The preparation of the graft copolymer resin (C) will be described in detail later as a specific example, but it is generally preferable to carry out as follows. That is, a predetermined amount of polybutadiene and/or styrene-butadiene copolymer as a rubbery polymer is dissolved in a monomer mixture consisting of a vinyl aromatic monomer and an unsaturated dicarboxylic acid anhydride. The amount of the rubbery polymer at this time is determined by taking into consideration the polymerization reaction rate, polymerization time, etc. Furthermore, the initial charging ratio of the monomer mixture is determined depending on the matrix-forming resin composition of the desired graft copolymer resin. The relationship between the initial composition of the copolymer and the composition of the produced copolymer will be explained. In Figure 1, the horizontal axis shows the monomer charge composition ratio, and the vertical axis shows the differential composition ratio of the produced copolymer.As a specific example, styrene-maleic anhydride copolymerization is performed at a polymerization temperature of 90°C. It is a figure which shows the monomer composition ratio at the time of implementation, and the composition ratio of the produced copolymer at that time.
For example, at point a on the horizontal axis, when the monomer composition ratio is styrene/maleic anhydride = 0.9932/0.0068, the resulting copolymer composition ratio is styrene/maleic anhydride = 0.80/0.20 (point b). It is shown that.
Therefore, from this relationship diagram, conversely, the composition ratio of the produced copolymer is
This exemplifies that in order to obtain 0.920/0.080 (point c), the monomer composition ratio needs to be 0.9982/0.0018, which is point d. However, the vertical axis of this figure is
This is the differential composition (instantaneous composition) of the produced copolymer, and the monomer composition ratio constantly changes as the polymerization progresses.
In order to obtain a copolymer with a constant composition ratio, it is necessary to add the missing monomer into the system. After dissolving the rubbery polymer in the monomer mixture, replace the polymerization system with an inert gas and, in the case of thermal polymerization,
Polymerization is initiated at 100-140°C, or at 80-120°C in the case of polymerization using a radical initiator. In the copolymerization of a vinyl aromatic monomer and an unsaturated dicarboxylic anhydride, the unsaturated dicarboxylic anhydride is usually added in order to obtain a copolymer having a certain composition. When a predetermined polymerization rate is reached or a predetermined polymerization time has elapsed, the polymerization mixture is rapidly cooled or a polymerization inhibitor is added to stop the polymerization, and the liquid is transferred to a vacuum dryer and heated under high vacuum (1 to
It devolatilizes at high temperature (160-240℃) under 5Torr). The residue after devolatilization is a milky white lump, and if necessary, it is pulverized into a fine powder using a pulverizer or the like. The obtained powder is separated into a rubbery polymer-containing component and a vinyl aromatic monomer and unsaturated dicarboxylic anhydride copolymer component by a solvent fractionation method, and the original sample is separated from the solvent-soluble component by the fractionation method. The unsaturated dicarboxylic anhydride content (weight %) was determined for the three solvent-insoluble samples, and the grafting rate was calculated using the following formula. Grafting ratio (G) = Weight of matrix resin grafted onto rubbery polymer (g) / Weight of rubbery polymer (g) x 10
0 (%) = c/b-c×100
(%) However, b: Content rate of unsaturated dicarboxylic acid anhydride in the fractionated soluble fraction [-] c: Content rate of unsaturated dicarboxylic acid anhydride in the fractionated insoluble fraction [-] As a composite system physical property improver Graft copolymer resin
The grafting rate of (C) is important for maintaining the physical properties of the final composite composition at a high level. When the grafting rate of this resin is lower than 30%, most of the resin (C) is
It is a styrene-maleic anhydride copolymer resin that is a matrix-forming resin component, and in reality, resin (A)
This is similar to the case where some rubbery polymer and a similar substance of component resin (A) are added to the composite system of resin (B), and it does not act effectively as a composite system modifier. On the other hand, when the grafting ratio exceeds 100%, the matrix resin component (branch polymer) grafted onto the rubbery polymer suppresses the properties of the trunk polymer, and rather the properties of the branch polymer itself are strongly reflected, resulting in a composite. The properties of the composition cannot be maintained at a high level. To explain this in more detail, it is necessary to estimate the effect of the graft copolymer resin (C) on improving the physical properties of the composite resin composition. It is reasonable to think that the greatest weakness of composite resins is their reduced impact resistance, and this weakness is due to the fact that microscopic analysis of the phase structure of composite resins shows that the phase interface becomes the starting point of fracture. Generally accepted. Therefore, in order to improve the physical properties of composite resin,
It goes without saying that it is effective to add a component that reinforces the composite phase interface. According to experiments, resin (A) and resin
The component reinforcing the interface in the composite of (B) is thought to be the graft copolymer component in resin (C), but the grafting rate of this graft copolymer resin is 30 to 100%.
It was found that those outside the range cannot effectively reinforce the composite phase interface. In other words, if the grafting ratio is too small or too large, the present graft copolymer resin (especially pure graft copolymer) will not be localized at the composite phase interface, but rather will be mostly absorbed in the component resin (B) or (A). It is estimated that as a result of this, the effect of its addition will be reduced. Any known method can be used to combine the component resin (A), the graft copolymer resin (B), and the graft copolymer resin (C) as a composite system property improver. For example, the three components are mixed and dissolved in a solvent common to (A), (B) and (C), such as a combination of a halogenated hydrocarbon and an aromatic compound or an aliphatic ketone and an aromatic compound, and then the solvent is evaporated. It is also possible to obtain the desired mixture by However, a more practical mixing method is to blend the powder and/or pellets using a regular tumbler mixer, Henschel mixer, etc.
Alternatively, it is convenient to pelletize using a 40 mmφ kneading extruder. The conditions in the kneading extruder are temperature.
Desirably 200-240°C, screw rotation speed 30-60 rpm, and residence time of several minutes. Component (A) in this composite composition
The ratio of
(A) is 30 to 70% by weight of the total composition, preferably 40% by weight.
It should be selected in the range of ~60% by weight. Similarly, component (B) is limited to 20% by weight or more in order to maintain a high level of impact resistance of the final composite resin composition, and 70% by weight or less in order not to reduce heat resistance or melt flowability. There is a need. More preferably, in the entire composition
It is 20-35% by weight. Incidentally, this necessarily stipulates that the preferred amount of the graft copolymer resin (C), which is a physical property improver, in the total composition is 5 to 40% by weight. In addition, to this composition, not only a heat stabilizer to prevent thermal deterioration of the resin, a lubricant to improve the fluidity and mold release properties of the composition, but also known fillers, pigments, etc. are added. This is not a problem as long as the substance and amount do not significantly reduce the physical properties of the final composite composition.
The mixed and kneaded resin composition may be cut into ordinary pellets or strips, and optionally shaped by a known press molding method, injection molding method, extrusion molding method, or the like. The shaped specimens were subjected to physical property evaluation tests using the method described below. Izod Impact Test ASTM D-138 Heat Deformation Temperature Measurement Test ASTM D-648 Melt Flow Test JIS K-6760 Examples of the present invention are shown below. Unless otherwise specified, numbers indicate parts by weight. Polymerization example of styrene-maleic anhydride copolymer resin (A) 9.93 kg of styrene (ST) and maleic anhydride were placed in 20 stainless steel reaction tubes equipped with stirring blades, reflux condenser, automatic temperature controller, heat medium circulation jacket, etc. Add 0.07Kg of (MAH) and dissolve. After replacing with _N2 , the internal temperature of the reactor was raised to 120°C while stirring.
The polymerization reaction was started when the internal temperature rose to 110°C, and the polymerization was then continued at an internal temperature of 120°C for 4 hours. During this polymerization period, MAH is successively added in the form of a melt in order to keep the monomer composition ratio of the copolymer to be constant. The addition schedule is the polymerization rate,
It is calculated from the copolymer composition and the monomer reactivity ratio in styrene-maleic anhydride copolymerization. After completion of polymerization for a predetermined time, the polymerization mixture was transferred to a vacuum dryer while being cooled, and heated to 160° C. at 2 Torr to devolatilize unreacted monomers. The obtained block-shaped transparent copolymer resin _A1 was pulverized into a fine powder using a pulverizer. The yield was 3.7 kg, and according to alkaline titration of the resulting resin, the maleic anhydride units in the copolymer resin were 6.7% by weight. c=0.5g/dl) was 1.01. Resins A ₂ and A ₃ were prepared using the same method as above, but differed only in the initial monomer charge and additional addition schedule. As the amount of maleic anhydride in the monomer mixture increases, the polymerization rate increases slightly, so the final polymerization rate is
The values increased in the order of A ₁ < A ₂ < A ₃ . The analytical values of A ₁ to _{A 3} are shown in Table -. [Table] Polymerization example of rubber craft styrene-maleic anhydride copolymer resin (C) A predetermined amount of styrene ( After adding ST), maleic anhydride (MAH) and a solvent and stirring to dissolve,
Cut the required amount of rubbery polymer into small pieces, add and dissolve. When the dissolution is completed, a molecular weight regulator is added as necessary, the system is replaced with _N2 , and a heating medium is circulated to raise the internal temperature of the reactor to 130°C. When the internal temperature of the stirring tank reached 120°C, polymerization was started, and after that, while maintaining the internal temperature of the polymerization solution at 130°C, additional MAH was added to control the polymer composition in the same manner as in the polymerization of resin (A) above. Do this. After 5 hours of polymerization, the contents were transferred to a vacuum dryer while cooling the reactor, and heated to 1 Torr, 180
The temperature was raised to ℃ and devolatilized. The block-shaped milky white resin was pulverized little by little using a pulverizer. Table 1 shows the analysis results of the four graft copolymer resins C ₁ to C ₄ thus obtained. [Table] Polymerization example of styrene-acrylonitrile-maleic anhydride ternary copolymer resin (abbreviated as SAM resin) In a stainless steel reactor equipped with stirring blades, reflux condenser, automatic temperature controller, heat medium circulation jacket, etc. , styrene 2.7Kg, acrylonitrile 0.27Kg,
0.03 kg of maleic anhydride (equivalent to a weight ratio of 90:9:1) and each monomer are weighed and mixed. After replacing the inside of the system with N ₂ , the temperature of the heat medium circulation tank is raised to raise the internal temperature to 90°C. When the internal temperature reaches 85° C. during the course of the polymerization, the acrylonitrile-maleic anhydride monomer mixture to be consumed during the polymerization is added at 10 minute intervals to initiate polymerization. During this time, the internal temperature of the polymerization solution was 90.
Maintain at °C. Additional addition was stopped after 2.5 hours of polymerization time, and after 160 minutes, the system was rapidly cooled to stop polymerization, and 0.5 parts by weight of Irganox 1010 manufactured by Ciba Geigy was added as a heat stabilizer and vacuum devolatilization treatment was performed. The analytical values of the obtained product are shown in Table 1. Polymerization example of rubber graft styrene-acrylonitrile-maleic anhydride copolymer resin (abbreviated as HI-SAM resin) This is almost the same as the polymerization of rubber graft copolymer resin (C), but when acrylonitrile is added, rubbery polymers such as polybutadiene Since the combination is difficult to dissolve in the monomer mixture, it is necessary to use a slightly increased amount of solvent (for example, toluene, etc.). Add 1.84Kg, 0.14Kg, 0.02Kg, and 1.0Kg of styrene, acrylonitrile, maleic anhydride, and toluene to the reaction vessel from the previous example in this order.
After charging and stirring thoroughly, polybutadiene (Diene NF35AS manufactured by Asahi Kasei Corporation) was chopped into small pieces of 0.40 kg and charged and dissolved. Once the polybutadiene rubber is sufficiently dissolved, the system is replaced with _N2 , the heating medium is circulated,
Raise the internal temperature to 120℃. In this case, since the system was pressurized due to acrylonitrile, a pump injection method using a solvent was used for the additional addition of the acrylonitrile-maleic anhydride monomer mixture. After polymerization for a predetermined period of time, a heat stabilizer was added and mixed with stirring, followed by vacuum devolatilization. The analytical values of the product are shown in the table. [Table] Example 1 50% of styrene-maleic anhydride copolymer resin _A3
1 part, 33 parts of ABS resin B ₁ (DP-606 manufactured by Nippon Gosei Rubber Co., Ltd., rubber content 42%) and graft copolymer resin
Weighed 17 parts of _C3 each and added Sumitomo Chemical as a heat stabilizer.
After adding 0.2 part of WXR manufactured by Co., Ltd., the mixture was thoroughly mixed in a mixer. This mixture was kneaded into pellets using a 40 mmφ single screw extruder manufactured by Osaka Seiki Co., Ltd. The extrusion conditions were a maximum cylinder temperature of 240°C and a screw motor rotation speed of 50 rpm. The pellets thus obtained were molded into specimens for physical property evaluation using an injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. The general operating conditions for this injection molding are cylinder temperature 230℃, mold temperature 80℃, injection pressure 80-100Kg/ ^cm2 ,
The molding cycle was 20 seconds for injection, 15 seconds for holding pressure, and 20 seconds for cooling. The molded specimen obtained was milky white and slightly glossy.
It exhibited a good appearance with no molding distortion or sink marks. The physical property evaluation values of this product are shown in the table.
It maintained practically useful physical properties with well-balanced heat resistance, impact resistance, melt flow, etc. Comparative Example 1 The same experiment as in Example 1 was conducted except that the graft copolymer resin C ₃ as a physical property improver was not used. However, the ratio of A ₃ and B ₁ was set to 60:40 in accordance with the weight fraction of Example 1. Although the appearance of the molded product was not particularly different from Example 1,
The measured physical property values were at a low level as shown in the table, clearly indicating that the addition of the _C3 component was essential. Examples 2 and 3 Instead of ABS resin B ₁ used in Example 1, ABS resin B ₂ (VS polymer manufactured by Japan Synthetic Rubber Co., Ltd.,
Rubber content 23.0%) in Example 2, and
Similar experiments were conducted using MBS resin B ₃ (manufactured by Rohm and Haas, Acryloid KM-653, rubber content 48.0%) in Example 3 to evaluate the appearance and physical properties. The results are shown in the table. The appearance was the same as that of Example 1, and Example 2 exhibited higher heat resistance, and Example 3 exhibited higher impact resistance. Comparative Example 2 This example shows an example in which the graft copolymer resin C ₃ as a physical property improver was not used in Example 2. As shown in the table, the effectiveness of _C3 as a modifier is evident in this example as well. Comparative Example 3 The quantitative ratios of styrene-maleic anhydride copolymer resin A ₃ of Example 1, ABS resin B ₁ and graft copolymer resin C ₃ were set to 15, 62 and 23 parts by weight, respectively, and Although this is an example in which a composition was prepared according to the ratio, the effect of adding the physical property improver _C3 was not exhibited at all. Examples 4 and 5 In the experiment of Example 1, the ratio of styrene-maleic anhydride copolymer resin A ₃ to ABS resin B ₁ and graft copolymer resin C ₃ was 38/3 in Example 4.
38/24 and in Example 5, the physical properties were examined with a slight change to 64/27/9. The results are shown in Table 1. By changing the composite composition ratio within the specific range of the present invention, for example, in Example 4, the formulation prioritized impact resistance the most, and in Example 5, on the contrary, styrene-maleic anhydride was used. Increasing the blending ratio of the copolymer resin resulted in a formulation that placed more emphasis on heat resistance, and was rather beneficial in developing characteristic physical properties. Example 6 In this example, styrene-maleic anhydride copolymer resin
In place of (A), the styrene-acrylonitrile-
Table 1 shows the results of an experiment using maleic anhydride ternary copolymer resin (SAM resin) with the same composition as in Example 1. Although the maleic anhydride content in the SAM resin was almost similar to that of resin A ₃ , the inclusion of acrylonitrile as the third component could still bring about some improvement in the impact resistance of the composite composition. I understand. Example 7 In Example 1, the same amount of the rubber grafted styrene-acrylonitrile-maleic anhydride ternary copolymer resin (HI-SAM resin) was used instead of the graft copolymer resin _C3 as a composite physical property improver. Exactly the same experiment was conducted except that The final product had a good appearance and excellent physical properties. The results are shown in the table. Comparative Examples 4 and 5 Table 1 shows the results when the same resin _A1 was used in place of the styrene-maleic anhydride copolymer resin _A3 in Examples 1 and 2. If the maleic anhydride content in the copolymer resin A is too low, the physical properties, particularly the heat resistance, of the composite composition will be insufficient. Comparative Examples 6 and 7 The results of using a graft copolymer resin with a graft ratio outside the predetermined value range as the composite system physical property improver in Example 1 are shown, and Comparative Example 6
These are the results of experiments in which the graft ratio was too low and Comparative Example 7 was where the graft ratio was too high.
The results are shown in Table 1, and there is almost no effect of adding the physical property improver. Comparative Example 8 As the styrene-maleic anhydride copolymer resin A, a styrene-maleic anhydride alternating copolymer resin (maleic anhydride monomer content in the resin PMAH = 48.7% by weight) separately prepared in the laboratory was used. An attempt was made to perform a kneading experiment with 60 parts of this resin and 40 parts of ABS resin _B1 , but the foaming decomposed during the experimental operation and a composite composition could not be obtained. Examples 8 and 9 The same experiments as in Examples 1 and 2 were conducted except that 50 parts of _A2 was used instead of the styrene-maleic anhydride copolymer resin _A3 . The results are shown in the table.
This shows that when the maleic anhydride content in copolymer resin A is slightly reduced, the heat resistance of the final composite composition decreases, but the impact resistance is approximately at the same level or higher. It was found that the physical properties of the composite were practically sufficient up to a content of about 14% by weight. Examples 10 and 11 In Examples 1 and 8, graft copolymer resin C ₃
Table 1 shows the results when the same amount of resin C ₂ with different maleic anhydride contents was used as a composite physical property improver instead of . As a result, although the heat resistance was slightly lower than that of Examples 1 and 8, the impact resistance was rather improved, and sufficient practical physical properties were exhibited. Comparative Example 9 In Example ₁ , ABS resin from Daicel Chemical Co., Ltd. (BD polymer rubber content =
Table 1 shows the results of an experiment conducted in exactly the same manner as in Example 1, except that the same amount of ABS (12%) was used.
The higher the rubber content in the resin, the better. [Table] [Table] [Table] [Table]

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the monomer composition ratio and the produced copolymer composition ratio in the case of polymerizing a styrene-maleic anhydride copolymer resin.

Claims (1)

[Scope of Claims] 1 (A) Vinyl aromatic monomer 65% based on polymer weight
~95 parts by weight, unsaturated dicarboxylic anhydride 10-35
A copolymer resin consisting of parts by weight and, if necessary, 0 to 30 parts by weight of a vinyl monomer copolymerizable with these.
(B) vinyl aromatic monomer in the presence of 15 to 70 parts by weight of a rubbery polymer consisting of polybutadiene and/or styrene-butadiene copolymer, based on the weight of the polymer composition; and a mixture of unsaturated nitrile monomers or (meth)acrylic acid ester monomers30
20-70% by weight of a graft copolymer resin obtained by graft copolymerizing ~85 parts by weight and (C) 5-50% by weight of a rubbery polymer consisting of polybutadiene and/or styrene-butadiene copolymer, based on the weight of the polymer composition. A mixture of a vinyl aromatic monomer, an unsaturated dicarboxylic acid anhydride, and optionally an unsaturated nitrile monomer or methacrylic acid ester monomer copolymerizable therewith in the presence of 50 to 95 parts by weight. A graft copolymer resin obtained by graft copolymerizing 5 to 40 parts by weight, and the grafting ratio is within the range of 30 to 100% by weight.
A heat-resistant and impact-resistant composite resin composition consisting of % by weight.