JPH07258501A - Nitrile resin composition - Google Patents

Abstract

PURPOSE:To provide a nitrile resin composition which is improved in compatibility, exhibits excellent thermal stability and chemical resistance at the same time, and has impact resistance, light resistance, thermal resistance and rigidity in a well-balanced manner. CONSTITUTION:The nitrile resin composition which comprises a graft copolymer comprising 30-95wt.% rubbery polymer in which acrylonitrile and an aromatic vinyl compound are grafted onto a rubbery polymer and the total amount of the acrylonitrile and the aromatic vinyl compound is 5-70wt.%, and a vinyl copolymer comprising methacrylonitrile and an aromatic vinyl compound. In this composition, the weight ratio of the graft copolymer to the vinyl copolymer is in the range of 5/95 to 50/50, and x and y satisfy the following relationships (wherein x is the weight percentage of the acrylonitrile to the total of the acrylonitrile and aromatic vinyl compound in the graft copolymer, and y is the weight percentage of the methacrylonitrile to the total of the methacrylonitrile and the aromatic vinyl compound in the vinyl copolymer): y<=2x+10, y>=1.5x-25, 15<=x<=70, and 40<=y<=95.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin having excellent compatibility, thermal stability and chemical resistance, and also having excellent physical properties balance among impact resistance, light resistance, heat resistance and rigidity.

[0002]

2. Description of the Related Art Rubber-reinforced resin represented by ABS resin has excellent mechanical properties such as impact resistance and tensile strength, and is easy to mold and process, and therefore automobile parts, home electric appliances, furniture such as desks and chairs. Widely used for general merchandise. ABS resin is generally produced by kneading a graft polymer obtained by grafting a copolymer of acrylonitrile and styrene onto a rubbery polymer such as butadiene rubber, and a copolymer of acrylonitrile and styrene (matrix AS). .

In this ABS resin, the amount of nitrile (= acrylonitrile / (acrylonitrile + styrene)) in the graft AS and the matrix AS of the graft copolymer must be the same or very close. That is, it is known that the resin can be designed only within a very narrow range of nitrile amount. This is POLYMER LE
TTERS (VOL.3, PP.1007-1015)
(1965)), it is believed that the two types of AS resins cause microphase separation when the amounts of nitriles are separated. That is, the graft copolymer and the matrix copolymer are phase-separated due to the separation of the nitrile amounts of the graft AS and the matrix AS, the impact resistance of the ABS resin is drastically reduced, and the original characteristics of the resin are not exhibited.

Further, it is known that the chemical resistance is enhanced by containing an AS resin having a high nitrile amount, and for that purpose, it is necessary to increase the nitrile amounts of both the graft AS and the matrix AS. JP-A-2-284
Japanese Patent No. 906 proposes a resin having improved chemical resistance and the like by increasing the acrylonitrile content. However, when the amount of nitrile is increased by increasing the content of acrylonitrile, both the matrix AS and the graft copolymer have very poor thermal stability, and the resin may burn or gel due to heat during extrusion or molding.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems, and in a wide range, the graft AS and the matrix AS are compatible with each other, and the thermal stability and the chemical resistance are excellent, and the impact resistance is high. It is to provide a nitrile resin composition in which physical properties such as properties are not deteriorated.

[0006]

Means for Solving the Problems As a result of intensive studies to overcome these problems, the present inventors have found that a copolymer of methacrylonitrile and an aromatic vinyl compound is a copolymer of acrylonitrile and an aromatic vinyl compound. The present invention has led to the present invention by discovering that it is a resin that widens the range of compatibility with and that it is a resin that solves the above problems.

That is, according to the present invention, the rubbery polymer in which the acrylonitrile and the aromatic vinyl compound are grafted on the rubbery polymer is 30 to 95% by weight, and the total amount of the acrylonitrile and the aromatic vinyl compound is 5 to 70% by weight. A nitrile resin composition comprising a graft copolymer (A) and a vinyl copolymer (B) comprising methacrylonitrile and an aromatic vinyl compound, wherein (A) / (B) is 5/95 to 5
It is in the range of 0/50 and (Acrylonitrile) / (Acrylonitrile +) of the above graft copolymer (A).
The weight% of (aromatic vinyl compound) is (x), and the weight% of (methacrylonitrile) / (methacrylonitrile + aromatic vinyl compound) of the vinyl copolymer (B) is (y).
Is a nitrile resin composition within the range represented by the following formula.

Y ≦ 2x + 10 y ≧ 1.5x−25 15 ≦ x ≦ 70 40 ≦ y ≦ 95 The present invention will be described in detail below.

The rubbery polymer used in the present invention has a glass transition point of 0 ° C or lower, preferably -20 ° C or lower. Specifically, dibutadiene rubber such as polybutadiene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber such as methyl polyacrylate, polyethyl acrylate, polybutyl acrylate, polyisoprene, polychloroprene. , Ethylene-propylene rubber, ethylene-propylene-diene terpolymer rubber, styrene-butadiene block copolymer rubber,
Block copolymers such as styrene-isoprene copolymer rubber and hydrogenated products thereof can be used. Preferred are polybutadiene, styrene-butadiene copolymer rubber, and acrylonitrile-butadiene copolymer rubber.

The proportion of the rubbery polymer in the graft copolymer (A) is used in the range of 30 to 95% by weight. If the proportion of the rubbery polymer is less than 30%, the impact resistance will be poor, and if it exceeds 95%, the workability will be poor. Furthermore, in terms of the balance between impact resistance and workability, the preferred range is 40-
It is in the range of 80% by weight, more preferably 50 to 70.
% By weight.

The total amount of acrylonitrile and aromatic vinyl compound in the graft copolymer (A) must be 5 to 70% by weight. If less than 5% by weight,
Since the compatibility with the matrix decreases, the rubber-like polymer aggregates, the surface gloss of the resin deteriorates, and the thermal stability deteriorates. If it is higher than 70% by weight, the impact resistance of the resin is lowered. The preferred range of the graft component is 10 to 60% by weight, more preferably 20 to 50% by weight.

The ratio of the rubbery polymer to the graft component in the graft copolymer (A) is measured by dissolving the polymer produced by the polymerization in acetone and separating and removing the insoluble matter by a centrifuge. be able to. The component that dissolves in acetone is a component that has not undergone a graft reaction (non-graft polymer) in the copolymer that has undergone a polymerization reaction,
The value obtained by subtracting the amount of the rubbery polymer from the acetone insoluble content is defined as the value of the graft component.

The mixing ratio (weight ratio) of the graft copolymer (A) and the vinyl copolymer (B) is (A) / (B) = 5/9.
It should be in the range of 5 to 50/50. (A)
When the amount is less than 5 parts by weight, the impact resistance is poor, and when it is more than 50 parts by weight, the rigidity is significantly low. Examples of the aromatic vinyl compound used for the graft copolymer (A) and the vinyl copolymer (B) include α-alkylstyrene such as styrene and α-methylstyrene, nuclear-substituted alkylstyrene such as p-methylstyrene, and halogen. Styrene, vinyl-substituted naphthalene, etc. These may be one kind or a mixture of two or more kinds. Preferred are styrene, α-methylstyrene, and a mixture of styrene and α-methylstyrene.

Further, the graft copolymer (A) is copolymerized with vinyl cyanide compounds such as methacrylonitrile and aromatic vinyl compounds such as styrene and α-methylstyrene within a range not impairing the object of the present invention. A possible monomer may be added. Examples of this monomer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like.

The vinyl copolymer (B) contains a monomer capable of copolymerizing with a vinyl cyanide compound such as acrylonitrile and an aromatic vinyl compound such as styrene and α-methylstyrene within a range not impairing the object of the present invention. May be. Examples of this monomer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like.

Next, the range of the amount of nitrile will be described. In the formula, x is the weight% of (acrylonitrile) / (acrylonitrile + aromatic vinyl compound) of the graft copolymer, and y is (methacrylonitrile) / (methacrylonitrile + aromatic vinyl) in the vinyl copolymer. Compound)
% By weight. Mixtures of acrylonitrile / aromatic vinyl compound copolymer and methacrylonitrile / aromatic vinyl compound copolymer in the range of y> 2x + 10 are incompatible. Further, the same is true in the range of y <1.5x-25. That is, y = 2x + 10 and y = 1.5x
The range surrounded by -25 is a compatible range.

In the range of x, 15 ≦ x ≦ 70 shows excellent physical properties. In the range of x <15, sufficient impact resistance cannot be obtained. When x> 70, cyclization reaction and cross-linking reaction of acrylonitrile occur during high temperature processing. Preferably 20 ≦ x ≦ 6
0, and more preferably 30 ≦ x ≦ 50. The range of y is shown by 40 ≦ y ≦ 95. When y <40, sufficient chemical resistance cannot be obtained. When y> 95, depolymerization occurs during high temperature processing, and decomposed gas is generated. Preferably 45 ≦ y ≦
90, and more preferably 50 ≦ y ≦ 80.

As described above, the acrylonitrile / aromatic vinyl compound copolymer and the methacrylonitrile / aromatic vinyl compound copolymer are y ≦ 2x + 10 and y ≧ 1.5x−.
The resin is compatible with a very wide range surrounded by 25, 10 ≦ x ≦ 70, and 40 ≦ y ≦ 95, and has sufficient impact resistance and chemical resistance. These ranges are indicated by a range surrounded by a thick line in FIG. 1 (a part which is obliquely rising to the right), and a more preferable range is shown by a range surrounded by a thin line (a part where the oblique lines rising to the right and the oblique lines rising to the left cross).

As a comparison, FIG. 2 shows a range of conventional ABS resins in which the acrylonitrile / aromatic vinyl compound copolymers are compatible with each other and can withstand practical use. This range is
It can be seen that the range is surrounded by z = x + 5, z = x-5, 10 ≦ x, and z ≦ 70, which is very narrow. (Z represents the nitrile amount of the other acrylonitrile / aromatic vinyl compound copolymer).

The following method was used to determine the compatibility. Each rubber-free copolymer was dissolved in acetone to give a 10% solution. The resin solution to be measured was mixed in the same amount well, and then a few drops of the solution were placed on a glass plate and air-dried. If the resin remaining after removing acetone with a vacuum dryer was transparent, the resin was compatible, and if it was cloudy, it was determined to be incompatible. Furthermore, the transparency of this resin was confirmed by applying heat of 200 ° C., and it was confirmed that it was not cloudy.

The vinyl copolymer (B) may contain a non-graft component produced during the production of the graft copolymer (A). However, the composition of the non-graft component derived from the graft copolymer (A) must be in a range compatible with the vinyl copolymer (B). The preferred molecular weight of the vinyl copolymer (B) is 3 at a polymer concentration of 0.5% by volume using methyl ethyl ketone as a solvent.
It is preferable that the reduced viscosity of the solution at 0 ° C. is in the range of 0.25 to 0.8. If it is lower than 0.25, the resin composition becomes very brittle, and if it is higher than 0.8, the fluidity and molding processability of the resin are significantly deteriorated. The reduced viscosity was measured by substituting the dropping time of the methyl ethyl ketone solvent and the dropping time of the resin solution, which were measured with a Canon-Fenske type viscous tube, into the following formula.

Reduced viscosity = [{(falling time of solution) / (falling time of solvent)}-1] /0.5 The method for producing the graft copolymer (A) in the present invention is not particularly limited and is conventionally known. It can be produced by solution polymerization, suspension polymerization, emulsion polymerization or the like, but typically, acrylonitrile and an aromatic vinyl compound are added to water, an emulsifier, an initiator and a chain transfer agent in the presence of a rubbery polymer. Graft polymerization is carried out by an emulsion polymerization method using a pH adjuster and the like, and then the obtained latex is salted out, dehydrated and dried by a known method.

The method for producing the vinyl copolymer (B) in the present invention is not particularly limited, but it can be produced by conventionally known bulk polymerization, emulsion polymerization, solution polymerization, suspension polymerization and the like. The method of mixing the graft copolymer (A) and the vinyl copolymer (B) is not particularly limited. It can be obtained by a conventional method, for example, kneading using a device such as an extruder, a kneader, a roll mixer, a Banbury mixer or the like. At this time, if necessary, within a range that does not impair the intended features of the present invention, antioxidants, antistatic agents, ultraviolet absorbers, flame retardants, pigments, dyes, lubricants, additives such as bleaching agents, and the like, Reinforcing agents such as glass fibers, carbon fibers and fillers can be added.

[0024]

EXAMPLES The following examples and comparative examples are for explaining the present invention more specifically, and are not limited to the following examples. In the examples, "part" is "part by weight".
And the measuring methods of each physical property are as follows. [Measurement Method] IZOD Impact Test: Based on ASTM D-256.

Chemical resistance: A sample (width 12.7 mm, thickness 1 m) that was compression molded and annealed at 80 ° C. for 24 hours.
A load of 200 g was applied to m), a gauze impregnated with toluene was placed on the flexible portion, and the time to break was measured. Thermal stability: The resin was retained in a melt indexer at 280 ° C. for 30 minutes, and gelation was confirmed.

Light resistance: 3 with a xenon weather meter
The ΔE of the test piece after irradiation for 00 hours was measured. Heat resistance (HDT): Based on ASTM D-648. Stiffness (FM): Based on ASTM D-790. [Method for producing graft copolymer]: To 40 parts of polybutadiene rubber latex (weight average particle diameter 0.3 μm), 100 parts of deionized water and 1.5 parts of potassium rosinate were added,
After substituting the gas phase with nitrogen, the temperature was raised to 70 ° C. continue,
Oxidized to a monomer mixture consisting of 24 parts of acrylonitrile, 36 parts of styrene, 0.1 part of cumene hydroperoxide as a polymerization initiator, 0.5 part of tertiary decyl merptane as a chain transfer agent, and 50 parts of deionized water. To accelerate the reduction reaction, an aqueous solution prepared by dissolving 0.1 part of sodium formaldehyde sulfoxylate, 0.005 part of ferrous sulfate and 0.03 part of ethylenediaminetetraacetic acid disodium salt was added over 7 hours, and 70 The reaction is completed at a polymerization temperature of ℃, graft copolymer (A-1)
A latex was obtained.

The graft copolymer (A-1) latex was freeze-salted out, the white polymer obtained by filtration was dried, and the acetone insoluble content was 62% by weight and the acetone soluble content was 38% by weight. . When the composition of this acetone-insoluble matter was measured by an infrared spectrophotometer, the content of the rubbery polymer was 65% by weight, and the content of the graft component was 35% by weight. In addition, the content of acrylonitrile in the graft component of the acetone-soluble component and the acetone-insoluble component was 39% by an infrared spectrophotometer.

27 parts of acrylonitrile was added to the monomer mixture.
33 parts styrene, tertiary decyl melptane 0.
A graft copolymer (A-2) was obtained by the same polymerization method as that of the graft copolymer (A-1) except that the amount was changed to 7 parts.
The acetone insoluble content and soluble content of this resin were 66
% And 34%. The contents of the rubber polymer and the graft component of the acetone-insoluble matter were 61 and 39% by weight, respectively, and the acrylonitrile content of the acetone-soluble matter was 43%, which were determined by an infrared spectrophotometer.

12 parts of acrylonitrile was added to the monomer mixture,
Styrene 48 parts, tertiary decyl melptane 0.
A graft copolymer (A-3) was obtained by the same polymerization method as that for the graft copolymer (A-1) except that the amount was 4 parts.
The acetone insoluble content and soluble content of this resin were 64
% And 36%. The contents of the rubber polymer and the graft component of the acetone-insoluble matter determined by an infrared spectrophotometer were 62 and 38% by weight, respectively, and the amount of acrylonitrile in the acetone-soluble matter was 22%.

36 parts of acrylonitrile,
24 parts styrene, tertiary decyl melptane 1.
A graft copolymer (A-4) was obtained by the same polymerization method as that for the graft copolymer (A-1) except that the content was 0 part.
The acetone insoluble content and soluble content of this resin were 62
% And 38%. The contents of the rubber polymer and the graft component of the acetone-insoluble matter determined by an infrared spectrophotometer were 65 and 35% by weight, respectively, and the amount of acrylonitrile in the acetone-soluble matter was 57%.

[Production method of vinyl copolymer]: 1.0 part of potassium rosinate was added to 100 parts of deionized water, the gas phase part was replaced with nitrogen, and then the temperature was raised to 70 ° C. Subsequently, a monomer mixture liquid consisting of 60 parts of methacrylonitrile, 40 parts of styrene, 0.25 part of tertiary decyl merptane as a chain transfer agent, and 0.15 part of cumene hydroperoxide as a polymerization initiator, and deionized. An aqueous solution prepared by dissolving 0.15 parts of sodium formaldehyde sulfoxylate for promoting the redox reaction in 50 parts of water, 0.0075 parts of ferrous sulfate and 0.045 parts of ethylenediaminetetraacetic acid disodium salt for 8 hours. Over 70 ° C
The reaction is completed at the polymerization temperature of the vinyl copolymer (B-
1) A latex was obtained.

The vinyl copolymer (B-1) latex was freeze-salted out, filtered and dried to obtain a resin having a reduced viscosity of 0.45. The methacrylonitrile content measured with an infrared spectrophotometer was 59%. 70 parts of methacrylonitrile, 30 parts of styrene, 0.2 parts of tertiary decyl mercaptan, 0.3 part of cumene hydroperoxide were used as the monomer mixture, and 0.3 parts of sodium formaldehyde sulfoxylate and sulfuric acid were used as the aqueous solution. A vinyl copolymer (B-2) was obtained by the same polymerization method as that for the vinyl copolymer (B-1) except that 0.015 part of ferrous iron and 0.09 part of ethylenediaminetetraacetic acid disodium salt were used. . The methacrylonitrile content determined by an infrared spectrophotometer was 68%,
The reduced viscosity was 0.42.

Methacrylonitrile 80 was added to the monomer mixture.
Parts, styrene 20 parts, cumene hydroperoxide 0.3 parts, except that the aqueous solution was sodium formaldehyde sulfoxylate 0.3 parts, ferrous sulfate 0.015 parts, ethylenediaminetetraacetic acid disodium salt 0.09 parts. Was subjected to the same polymerization method as for the vinyl copolymer (B-1) to obtain a vinyl copolymer (B-3). The methacrylonitrile content determined by an infrared spectrophotometer is 77%,
The reduced viscosity was 0.40.

Methacrylonitrile 30 was added to the monomer mixture.
Parts, styrene 70 parts, cumene hydroperoxide 0.1 part, and the aqueous solution was changed to sodium formaldehyde sulfoxylate 0.1 part, ferrous sulfate 0.005 part, ethylenediaminetetraacetic acid disodium salt 0.03 part. Was subjected to the same polymerization method as for the vinyl copolymer (B-1) to obtain a vinyl copolymer (B-4). Methacrylonitrile content determined by infrared spectrophotometer is 32%,
The reduced viscosity was 0.37.

60 parts of acrylonitrile was added to the monomer mixture.
40 parts styrene, tertiary decyl melptane 1.
A vinyl copolymer (B-5) was obtained by the same polymerization method as that for the vinyl copolymer (B-1) except that the amount was changed to 2 parts. The acrylonitrile content determined by an infrared spectrophotometer is 55.
%, And the reduced viscosity was 0.38. 90 parts of methacrylonitrile, 10 parts of styrene, 0.35 part of cumene hydroperoxide, 0.1 part of tertiary decyl mercaptan were used as the monomer mixture, and 0.35 parts of sodium formaldehyde sulfoxylate and sulfuric acid were used as the aqueous solution. 1 iron 0.
Vinyl copolymer (B-1) except that 0175 parts and 0.105 parts of ethylenediaminetetraacetic acid disodium salt were used.
The same polymerization method as in (1) above was carried out to obtain a vinyl copolymer (B-6). The acrylonitrile content determined by an infrared spectrophotometer was 85%, and the reduced viscosity was 0.46.

[0036]

Examples 1 to 4 and Comparative Examples 1 to 4 Graft copolymer (A
-1 to A-4) Latex and vinyl copolymer (B-1 to A-4)
B-6) was subjected to latex blending so as to have the resin composition shown in Table 1, 1 part of the antioxidant was added, and the mixture was heated to 60 ° C.
1 part of aluminum sulfate was added with stirring to coagulate the latex. The solidified product was washed with water and dried to obtain a white flake-shaped resin composition.

[0037]

[Table 1]

The white flake-shaped resin composition thus obtained was kneaded and granulated by a twin-screw extruder having a cylinder temperature of 240 ° C. Then, a test piece for measuring physical properties was obtained by injection molding at a molding temperature of 240 ° C. The physical property measurement results are shown in Table 2.

[0039]

[Table 2]

As shown in Table 2, the resin composition which does not satisfy the conditions specified in the present invention has poor impact resistance and / or chemical resistance, and further has thermal stability, light resistance, heat resistance and rigidity. Can not be a resin with excellent balance. It can be seen that the resin composition of the present invention solves the conventional problems.

[0041]

Industrial Applicability According to the present invention, a resin having a wide range of compatibility, thermal stability and chemical resistance, and having excellent balance of physical properties such as impact resistance, light resistance, heat resistance and rigidity is obtained. be able to.

[Brief description of drawings]

FIG. 1 shows acrylonitrile (A
It is a figure which shows the range of this invention, and a more preferable range in the relationship between the ratio (x) of N) and the ratio (y) of the methacrylonitrile (MAN) in a vinyl copolymer.

FIG. 2 shows acrylonitrile (A
It is a figure which shows a preferable range in the relationship between the ratio (x) of N) and the ratio (z) of acrylonitrile (AN) in a vinyl copolymer.

Claims (1)

[Claims] 1. A rubbery polymer in which acrylonitrile and an aromatic vinyl compound are grafted onto a rubbery polymer is 30 to 30.
95% by weight, graft copolymer (A) in which the total amount of acrylonitrile and aromatic vinyl compound is 5 to 70% by weight
And a vinyl copolymer (B) comprising methacrylonitrile and an aromatic vinyl compound, comprising:
The above (A) / (B) is in the range of 5/95 to 50/50, and the weight percentage of (acrylonitrile) / (acrylonitrile + aromatic vinyl compound) in the above graft copolymer (A) is (x). And a nitrile resin composition within the range represented by the following formula, where (y) is the weight% of (methacrylonitrile) / (methacrylonitrile + aromatic vinyl compound) of the vinyl copolymer (B). object. y ≦ 2x + 10 y ≧ 1.5x−25 15 ≦ x ≦ 70 40 ≦ y ≦ 95