JPH0881523A - Production of abs resin having various surface morphology - Google Patents

Abstract

PURPOSE: To arbitrarily control the surface morphology of a molded ABS resin article without detriment to its impact strength by subjecting an ABS resin separated and recovered after polymn. and having a specific rubber-particle morphology to shear with a twin-screw extruder. CONSTITUTION: After the completion of polymn., unreacted monomers and/or a solvent is separated and recovered to obtain an ABS resin which gives an injection molded article wherein, when a plane parallel to the surface of the article is observed with an electron microscope photograph by ultramicrotomy, two kinds of rubber particles, one (A) having a ratio of the length (a) to the breadth (b) of 1.5 or lower and the other (B) having a ratio of a/b of higher than 5.0, are present at a depth of 0.5-1.5μm from the surface in such amts. that the area of particles A and that of particles B are 10% or higher and 0.01-90%, respectively, based on the total area of the rubber particles observed with the photograph. The resin is subjected to shear with a twin-screw extruder having a kneading disk or rotor to control the area of particles B to 0-95% of that before subjecting to shear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a morphology of a molded article, and more particularly to a method for producing an ABS resin molded article which controls the morphology of the surface of the molded article. According to the present invention, the rubber particle morphology on the surface of the molded product can be freely changed, so that the characteristics of the surface of the ABS resin can be extremely easily developed, and for example, gloss and matte can be arbitrarily controlled.

[0002]

2. Description of the Related Art Conventionally, various methods have been used to control surface characteristics of ABS resins.
For example, by using rubber particles with a large diameter, the rubber particles on the surface (the same applies to the particles inside)
The surface characteristics have been controlled by increasing the shape or, conversely, by using rubber particles having a small rubber particle diameter to reduce the shape of the rubber particles on the surface and inside.
That is, in the prior art, it is common to control the rubber particle size from the manufacturing process of ABS resin, so that not only the surface but also the impact and rigidity of the molded product have an effect of controlling the rubber particle size, It was a big problem in terms of balance. For example, when rubber particles having a large particle size are used to impart matte properties, the matte properties of the surface are excellent, but on the other hand, there is a problem that the impact strength is reduced.
Further, when the rubber particle size is reduced to impart gloss to the surface, the gloss is excellent, but the impact strength decreases, so a large amount of rubber component is required. Another method for controlling the surface morphology of the ABS resin is to specify molding conditions at the molding stage. For example, it has been practiced to use a high mold temperature during injection molding in order to maintain high gloss. In this case, molding conditions are limited,
The molding injection cycle becomes long, and there remains an important productivity problem.

Further, conventionally, in order to maintain the surface gloss at a specific value, it has been necessary to strictly control the polymerization step. In the present invention, the surface characteristics can be strictly controlled not only in the control of the raw material resin production but also in the extrusion process.

[0004]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for arbitrarily controlling the surface morphology of a molded article of ABS resin while maintaining impact strength and the like.

[0005]

In the present invention, the morphology of rubber particles (rubber particle morphology) observed on the surface of a molded article is controlled by using a technical means which is completely different from the conventional one. That is, in the present invention, a rubber-like polymer particle is prepared by supplying a raw material containing at least a styrene-based monomer and an acrylonitrile-based monomer, and a rubber-like polymer to a polymerization step and polymerizing a part or all of the monomer. After the step of polymerizing the polymer including (rubber particles) formation, the mixed solution containing the polymer, the unreacted monomer and / or the solvent is heated, and at the same time or after heating, the mixture is introduced into a decompression chamber to remove the monomer and A molded product (molded product 1) having a separation / recovery step of separating the solvent from the resin component and injection-molding the resin that has exited the separation / recovery process is a rubber particle observed on the surface of the molded product. home,
Particle A having a ratio a / b of major axis a to minor axis b of 1.5 or less, and particle B having a ratio a / b of major axis a to minor axis b of 5 or more.
have. (As a method for obtaining the molded article 1 in the present invention, since the morphology of the resin obtained by the polymerization is measured, a sample valve is provided at the outlet of the separation / recovery step, and the resin is taken out in the form of a string and cooled in a water tank. To obtain a strand, which is then cut into pellets to obtain a molded product 1 by injection molding.) After such a resin is separated and recovered, these particles A are extruded by a twin-screw extruder having a shearing effect. -It was not known at all that the amount of particles B could be controlled. The inventors of the present invention observed rubber particles, particle A, observed near the surface of the molded product.
The inventors have found that the gloss of the surface of a molded article can be arbitrarily controlled by an unprecedented method in which the proportion of rubber particles having different forms, such as B and B, is adjusted by an extruder.

That is, [I] A raw material containing at least a styrene-based monomer, an acrylonitrile-based monomer, and a rubber-like polymer is supplied to a polymerization step, and a part or all of the monomer is polymerized to produce rubber particles. After the step of polymerizing the polymer including forming, the mixed solution containing the polymer, the unreacted monomer and / or the solvent is heated, and at the same time or after the heating, the mixture is introduced into a decompression chamber to remove the monomer and / or the solvent. From the surface of a molded product (molded product 1) obtained by injection-molding a resin that has a separation / recovery process of separating from a resin component
When the rubber particles present at a depth of 1.5 μm are observed on an electron micrograph of a plane parallel to the surface of the molded product by an ultrathin section method, the ratio a / b of the major axis a and the minor axis b is 1.5 or less. Particle A,
And at least two types of particles B having a ratio a / b of the major axis a to the minor axis b of 5 or more and the total area of the rubber particles observed by an electron micrograph by the ultrathin section method is 10
The area of particles A is at least 10% or more when 0%,
The ABS resin in which the area of the particles B is 0.01 to 90%,
[II] After leaving the separation and recovery step, shearing is applied by a twin-screw extruder having a kneading disc or a rotor, whereby the surface of the obtained molded product (molded product 2) is molded by the same method as described above, that is, molding. 0.5 to 1.5μ from the object surface
The parallel plane at a depth of m is observed by an electron micrograph by an ultrathin section method, and the area of the particles B is 0 to 95% when the ratio of the particles B observed in the molded article 1 is 100%. A way to control. The present invention is characterized in that particles A and particles B are present on the surface of a molded product (molded product 1) obtained by injection molding the resin that has been subjected to the separation and recovery step. That is, of the rubber particles existing at a depth of 0.5 to 1.5 μm from the surface of the molded article 1, the total area of the observed rubber particles is 10
If 0%, 10% or more is the area of the particle A, preferably 10 to 50%, more preferably 10 to 40%,
Further, 0.01 to 90% is the area of the particles B, preferably 0.
It is characterized by occupying 05 to 50%, more preferably 0.1 to 30%. In the present invention, if the area of the particles A is less than 10% or the area of the particles B is less than 0.01%, the morphology of the rubber particles on the surface, which is the object of the present invention, cannot be controlled and the gloss is locally low. Part arises. On the other hand, if the content of the particles B exceeds 90%, a streak pattern is generated on the surface of the molded product even if the treatment with an extruder is performed, which is not preferable.

Further, in the present invention, a raw material containing at least [I] a styrene-based monomer, an acrylonitrile-based monomer, and a rubber-like polymer is supplied to a polymerization step to polymerize a part or all of the monomer. After the step of polymerizing the polymer containing the rubber particles, the mixed solution containing the polymer, the unreacted monomer and / or the solvent is heated, and at the same time or after heating, the mixed solution is introduced into the decompression chamber to remove the monomer and / or Alternatively, it has a separation / recovery step of separating the solvent from the resin component, and the resin exiting the separation / recovery step is injection-molded to obtain a depth of 0.5 to 1.5 μm from the surface of the molded article (molded article 1). The existing rubber particles are
When observing the plane parallel to the surface of the molded article with an electron micrograph by the ultrathin section method, it has at least two types of morphology, particle A and particle B, and is observed by the electron micrograph with the ultrathin section method. The ABS resin in which the area of the particles A is at least 10% or more and the area of the particles B is 0.01 to 90% when the total area of the rubber particles is 100%, is discharged from the [II] separation and recovery step, and A twin-screw extruder having a kneading disk or a rotor is used to evaporate the water added to the resin and the added water between the separation / recovery outlet and the part where the kneading disk or the rotor is installed (kneading zone). A molded product having a part and evaporating the added water is obtained by applying shear using an extruder provided at the same time as or immediately before the kneading zone entrance. The surface of the molded product 2) was observed by the same method as described above, that is, a parallel plane having a depth of 0.5 to 1.5 μm from the surface of the molded product was observed by an electron micrograph by the ultrathin section method, and the area of the particle B was measured as described above. This is a method of controlling the proportion of particles B observed in the molded article 1 to be 0 to 95% when the proportion is 100%. The proportion of water added at this time is 0 to 15 parts by weight, preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 7 parts by weight with respect to 100 parts by weight of the resin extruded per unit time. . If the amount of water added exceeds 15 parts by weight, the processing capacity of the extruder is lowered and the productivity is affected, which is not preferable. In addition, sufficient shearing force is applied in the kneading zone by adding and evaporating water immediately before the kneading zone and lowering the resin temperature at the exit of the recovery step by 0 to 60% immediately before the kneading zone. When water is not added, the temperature of the extruder cylinder is adjusted to 0 to 60% lower than the resin temperature at the exit of the recovery process at the portion where the kneading disk is installed in the extruder or immediately before that. Sufficient shear force is applied to the resin, as in the case of adding. However, when the resin temperature is lowered by the temperature of the cylinder, the size of the extruder is limited, and in the case of a large-sized extruder, the resin temperature cannot be controlled by the cylinder temperature.

In the present invention, the ratio L / D of the screw length (L) of the extruder to the cylinder diameter (D) is 10 to 50.
Are preferred. It is more preferably 15 to 35, still more preferably 25 to 30. The kneading zone is 5 to 60% of the effective cylinder length, preferably 10 to
A twin-screw extruder equipped with a kneading disk so as to be 50% is used. If the kneading zone is less than 5% of the effective cylinder length, sufficient shearing will not be applied, and if it exceeds 60%, the shearing will be excessive and the resin will deteriorate due to the shearing heat generation effect.

The effective screw length in the present invention means the length of the screw excluding the ground portion at the base of the screw and the conical portion at the tip, and is usually indicated as L / D or a multiple of D mentioned above. .

In the present invention, as an extruder, the ratio D / d of the cylinder diameter (D) and the groove depth (d) of the screw element is 3 to 12, preferably 3 to 10, and more preferably 3 to 8. . The screw element is 40 to 95% of the effective length of the screw, preferably 50 to 90%,
It is more preferably 50 to 80%.

Here, the groove depth (d) of the screw element represents the distance from the bottom to the top of the screw element. This is because unnecessary shearing is not applied except in the kneading zone, and by using the above screw element, deterioration of the resin is suppressed and deterioration of the hue and the like is suppressed. If such a screw element is less than 50% of the effective screw length, the propulsive force of the resin is lowered, the residence time distribution of the resin in the extruder is widened, and the residence time becomes long, which leads to deterioration of the resin. If the screw element exceeds 95% of the effective length of the screw, shearing force is not applied.

The extruder in the present invention is one of the equipment used for extrusion molding and compounding, and the material is continuously heated, melted and kneaded between a portion called a cylinder and a rotary screw. It is extruded from a die to be molded or pelletized, and the amount of shear varies depending on the shape of the rotating screw and the like. In the present invention, a twin-screw extruder is especially used. A twin-screw extruder has two rotating screws installed in parallel, and the same-direction rotating type in which the two screws rotate in the same direction and the different-direction rotating type in which the two screws rotate in different directions There are different purposes and performances.

Further, the screw element in the present invention is a part constituting a screw of a twin-screw extruder, and there are a forward screw type and a reverse screw type. The screw element has the ability to push the resin in the direction of flow or the ability to apply pressure by causing it to flow backward. Further, the kneading disk in the present invention is a part constituting a screw of a twin-screw extruder like the screw element, and is a mixing part for the purpose of kneading. There are various types of kneading discs such as a double-row disc and a triple-row disc. The rotor has an oval cross section, and the flight consists of forward and reverse threads. That is, a combination of two kneading disks consisting of a forward screw and a reverse screw is continuous and fixed. By combining these screw elements and a kneading disc rotor, it is possible to give the extruder performance depending on the purpose.

The morphology of the surface of the molded product affects the surface characteristics of the molded product, and even if the average particle diameter of the rubber particles produced from the polymerization step is the same, the gloss of the surface of the molded product is improved if the area ratio of the particles B is small. On the contrary, when the area ratio of the particles B increases, the surface of the molded product is matted. In the present invention, not only the rubber particle size from the polymerization step but also the ratio of the area of the particle B can be controlled by an extruder so that the characteristics of the surface of the molded product can be adjusted arbitrarily from the same raw ABS resin. Industrial benefits are extremely high. In the method of controlling the gloss by adjusting the rubber particles of the raw material by the conventional method, the manufacturing process is very long. Especially when changing the grade from the matte resin to the high gloss resin, the
Over time, products of different gloss are inevitably produced to modify the properties of the S resin. In an ordinary industrial plant, if the residence time of all steps is 4 hours, the above-mentioned non-genuine product will be produced for about 4 to 12 hours. In the meantime, the products have not only a half-finished gloss but also a change, so that the applications are extremely limited. Industrially, in order to produce a wide variety of grades in one plant, it is extremely important for the productivity of the plant that non-genuine products are generated during grade replacement.

On the other hand, in the method of the present invention, which is the final stage of the process, the process time is short, and the resin having the desired gloss can be obtained by easy adjustment.

The ABS resin referred to in the present invention is a rubber-like polymer, a styrene monomer, an acrylonitrile monomer, and
If necessary, it is a resin composed of a copolymer of other monomers. Here, as the styrene-based monomer, styrene, α-
Alkyl monovinylidene aromatic monomers (eg α-methylstyrene; α-ethylstyrene; α-methylvinyltoluene; α-methyldialkylstyrene; etc.), ring-substituted alkylstyrenes (eg om- and p-vinyltoluene) O-ethylstyrene; p-ethylstyrene;
2,4-dimethyl styrene; p-tertiary butyl styrene; etc.), ring-substituted halostyrenes (eg o-chlorostyrene; p-chlorostyrene; o-bromostyrene;
2,4-dichlorostyrene; etc.), ring-alkyl, ring-halo substituted styrene (eg 2-chloro-4-methylstyrene; 2,6-dichlorostyrene; etc.) vinylnaphthalene, vinylanthracene, or a mixture thereof is used. To be Generally alkyl substituents have 1 to 4 carbon atoms and include isopropyl and isobutyl groups. One or a mixture of these monovinylidene aromatic monomers is used. Further, as the acrylonitrile-based monomer,
Examples thereof include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, and mixtures thereof.

The rubbery polymer is not particularly limited as long as it shows a rubbery state at room temperature, but preferably polybutadienes such as conjugated 1,3-dienes (eg butadiene; isoprene; etc.) and styrene. -Butadiene copolymer, EPDM (ethylene-propylene-diene methylene linkage) and the like.

The other monomer in the present invention is styrene,
The monomer is not particularly limited as long as it is a monomer copolymerizable with acrylonitrile, and examples thereof include acrylates such as methylmethacrylate and maleimides such as N-phenylmaleimide and cyclohexylmaleimide.

The ABS resin composition is styrene 5
0 to 95 parts by weight, acrylonitrile 5 to 50 parts by weight, butadiene polymer, or styrene-butadiene block copolymer 3 to 30 parts by weight are preferred. A preferable method for obtaining a resin having these compositions is to polymerize styrene and acrylonitrile using an organic peroxide as an initiator in the presence of a rubbery polymer. As the polymerization method, continuous bulk polymerization and solution polymerization are preferably used.

The ABS resin used in the present invention is the above-mentioned ABS resin and a resin containing the ABS resin as a component, and the ABS resin-containing resin means the ABS resin and another resin such as polycarbonate. , A mixture of polyphenylene ether, polypropylene, polystyrene, acrylonitrile-styrene copolymer resin or the like, a mixture of ABS resin and a flame retardant, a glass filler, a mixture of talc and the like, as long as it is a resin containing an ABS resin as a component, particularly limited Not something to do.

The ABS resin molded product used in the present invention is a molded product obtained by molding and processing an ABS resin.
Utilizing the mechanical and chemical characteristics of the system resin, it is used as a mechanical component, or as a final product such as stationery supplies and toys. As the molding process, a conventional resin molding method known so far is used, and examples thereof include injection molding and extrusion molding. The injection molding method is preferred. As preferable injection molding conditions, the cylinder temperature of the molding machine is 170 ° C to 280 ° C, preferably 180 ° C.
To 260 ° C, more preferably 200 ° C to 250 ° C,
The mold temperature is 30 to 90 ° C.

The area for defining the morphology of interest in the present invention is set to have a depth of 0.5 to 1.5 μm from the surface so that the rubber particles existing in the depth of this range have a specific morphology which has never been obtained. It is based on the finding that the surface characteristics of the molded product can be controlled by. The fact that 0.5 to 1.5 μm near the surface is based on the fact that the existence state of rubber particles was found to be substantially constant within this depth without depending on the depth. . That is, when the depth is less than 0.5 μm, there are many variations in the morphology of the rubber particles, and when it exceeds 1.5 μm,
Since the existing state changes depending on the depth, it is not suitable for specifying the morphology of rubber particles that correlates with the surface characteristics.

In the present invention, the morphology of the rubber particles is measured in parallel to the surface of the molded product. This parallel cross section is obtained by cutting the molded product into ultrathin sections in parallel with the surface of the molded product using a microtome. At this time, the thickness of each sample cut by a microtome is set to 0.05 μm, and the samples are sequentially cut from the surface, and the morphology is measured using the 11th to 30th samples.

The particle A in the present invention is an electron micrograph of such a sample, and when the major axis of the rubber particles is a μm and the minor axis is b μm, the ratio a / b of a and b is 1.5.
The following is defined as particle A. B is a particle having a / b of 5 or more.

The major axis a referred to in the present invention represents the maximum length of the distance between two points on the circumference of the rubber particles observed in the electron micrograph by the ultrathin section method, and the minor axis b is the major axis a. Shows the length of the rubber particles perpendicular to the major axis a at the point a / 2. Under such a constraint condition, when calculating the areas of the particles A and B, the size of the visual field to be observed with the electron microscope is determined so that the total area can be 1000 μm ² or more. This number is not particularly limited, but the field of view of the electron microscope is the size of the field of view containing 1000 or more rubber particles.

In the present invention, a resin having particles A and particles B when a parallel surface having a depth of 0.5 to 1.5 μm from the surface of the molded article 1 is observed with an electron microscope by an ultrathin section method. Is subjected to shearing by a twin-screw extruder in a molten state that has left the separation and recovery step. When the resin thus obtained was molded (molded product 2) and the surface of the molded product was observed by an electron micrograph in the same manner as in molded product 1, the area ratio of particles B observed in molded product 1 was 100%. Then, by setting the area ratio of the particles B in the molded product 2 to 0 to 95%, the surface characteristics of the molded product can be arbitrarily controlled.

For example, the morphology of the molded product 2 is such that the ratio of the area of the particle B in the molded product 1 (B ₁ ) and the degree of shearing of the extruder cause the ratio of the area of the particle B in the molded product 2 (B ₂ ).
It is determined by the degree of change in the ratio of the area of the particle B to the particle (change rate of the particle B). That is, the rate of change of the particles B can be adjusted by combining the degree of shearing of the extruder and B ₁ .

For example, the area ratio of the particles B observed in the molded article 1 is generated by the fluctuation of the recovery temperature in the separation / recovery step of the ABS resin manufacturing step by the solution or bulk polymerization method.
For example, the resin average temperature (T _AV ) at the recovery outlet in the separation / recovery step of separating the solvent / unreacted monomer from the resin component in the ABS resin manufacturing step by the bulk polymerization method is 170 to 28.
Within the range of 0 ° C, the resin temperature at the recovery outlet is changed to
By adjusting the product of the temperature variation rate (T _de ) of the recovery outlet with respect to _AV and the number of temperature variations per hour (N _CT ), particles B observed on the surface of the molded article after molding are produced. To do. The larger the product of T _de and N _CT, the more the number of rubber particles finally forming particles B in the molded product can be increased.

The average value (T _AV ) of the recovery temperatures referred to in the present invention is calculated by the following equation (Equation 1).

[0030]

[Equation 1] The temperature variation rate (T _de : temperature variation rate per hour) referred to in the present invention is calculated by the following equation (Equation 2).

[0031]

[Equation 2] Temperature fluctuation rate (T _de ) = ((T _max −T _min ) /
T _AV ) × 100 (where T _max is the maximum temperature of recovery temperature per hour, T
_min is the minimum temperature. The number of temperature fluctuations per hour is called the number of temperature fluctuations per hour (N _CT ) (however, fluctuations within a temperature fluctuation rate of 0.5% are ignored), and the differential value of temperature with respect to time is Indicates the number of times it changes to positive or negative.

In the present invention, the average value T _AV of the recovery temperature, the temperature variation rate T _de , and the number of times of temperature variation N _CT per hour
Runs with the average value of the recovery temperature for 3 hours or more constant,
It is calculated from the measured values in that section.

By adjusting the product (F) of T _de and N _CT , particles capable of becoming particles B are formed on the surface of the molded product after the molding process. In the present invention, those having the above F value of 0.5 to 150 can be used, and particularly preferable results are obtained by mixing two or more kinds of resins having different F values. Also in this case, an average value obtained from the mixing ratio and the F value and falling within the range of 0.5 to 150 can be used. For example, when F is 0.5 to 15, 0.01 to 1% of particles B are produced, and the obtained resin has an average rubber particle diameter of 0.05 to 1 μm, preferably 0.1 to 1.
If it is 0.8 μm, a resin having high gloss can be obtained. F is 3
If it exceeds 5 and 150 or less, 40 to 90% of particles B are produced, and if the rubber particle average diameter is 0.5 to 3 μm, preferably 1 to 2.5 μm, a resin having a matting effect is obtained. can get. In the method of the present invention, for example, the particles B are added in an amount of 0.01 to 1
% High gloss resin can be processed by an extruder with a high shearing effect to obtain a resin with a higher gloss, and even a resin with a matting effect can be obtained from one resin. It can be adjusted to an appropriate gloss depending on the application.

For example, the resin obtained by the above method is fed into an extruder in a molten state. The extruder used here is a twin-screw extruder equipped with a kneading disk or a rotor, and a portion to which water is added between the outlet of the separation / recovery process and the kneading zone and the kneading zone or at the same time. A twin-screw extruder having a portion for evaporating the water added immediately before is used. The proportion of water added is 0 to 15 parts by weight, preferably 1 to 10 parts by weight, and more preferably 1 to 7 parts by weight, based on 100 parts by weight of the resin processed by the extruder. The resin temperature can be lowered by adding water to the portion before the kneading zone to evaporate it, and the shearing force applied to the resin in the kneading zone can be increased. In addition to water, a low boiling point organic solvent may be mixed and used.

In the present invention, when there is no portion to which water is added before the kneading zone, the cylinder temperature of the extruder is adjusted to 0 to 60% of the resin temperature at the exit of the recovery step at the same time as or immediately before the kneading zone. When it is desired to obtain a product having a lower gloss and higher gloss, the effect of the present invention can be obtained by reducing the amount by 15 to 60%. However, in the case of a large extruder,
Since it is difficult to lower the resin temperature, the method of adding water is preferable. In the present invention, the surface morphology of the obtained resin is determined by the degree of temperature fluctuation in the separation and recovery step and the degree of shear applied to the resin in the extrusion step. The degree of shear applied to the resin in the extrusion step is calculated by the following formula (Equation 3) when a two-row kneading disk is mounted in a co-rotating twin screw extruder.
The shear index (S) represented by (Equation 4) is used.

[0036]

Γ _m = (dNE + DNE) × π × N / {(DB
-DNE) / 2} dNE: Minor diameter of kneading disc (mm) DNE: Major diameter of kneading disc (mm) N: Screw rotations per second (rps) DB: Cylinder diameter (mm)

[0037]

(4) S = (350−T ₁ ) × 0.02 × γ _m × (θ
/ 60) × L / 100 T ₁ : resin temperature at inlet of kneading zone (° C.) θ: residence time of resin in extruder (sec) L: ratio of kneading zone to effective screw length (%) The rate of change (B _D ) of the particles B is determined by B ₁ . The change rate B _D of the particles B is obtained by the following equation (Equation 5).

[0038]

[Formula 5] B_D= (B₁-B₂) / B₁× 100 Above B₁-The change rate B of the particle B using S_DGiven an example
Speaking of B₁Is 0.01 to 10%, S is 100 or less
B_DIs 0 to 30%, S is in the range of over 140 B _D40 ~
70%. For example B₁Is 40 to 90%, S is
B below 60_D0 to 30%, S exceeds 100
B_DIs 50 to 90%.

In other words, if an ABS resin is produced so as to obtain the molded product 1 having a certain B ₁ , various morphological products can be obtained by changing S. The co-rotating mesh type screw is a screw type of a twin-screw extruder, and two screws rotate in the same direction. The mesh type is a type in which the peaks and valleys of two screws are completely meshed with each other on the line connecting the screw shafts.

The shear index (S) in the present application is 20 to 300,
Preferably 30-250, more preferably 50-20
0.

The resin molded product obtained by the method of the present invention can control surface properties without deteriorating other physical properties such as impact strength, and is therefore widely useful as a component in the industrial field such as electric equipment and computers. Further, it is particularly useful as a molded product such as a cosmetic container, toy, stationery and the like.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0043]

EXAMPLES The present invention will be described in more detail below with reference to examples. The performance evaluation was measured according to the following criteria. (1) Gloss measurement Measurement of gloss level in JIS K7105 (60 ° specular gloss)
According to the measuring method of 1., the gloss was measured for three test pieces of 10 mm × 50 mm, and the average value was obtained. (2) Measurement of Impact Strength The impact strength was measured by the Izod impact test method (JIS-K7110) using a molded product as a test piece cut out. (3) Measurement of heat resistant temperature The Vicat softening point was evaluated according to ASTM DI525 using a sample obtained by cutting a test piece from a molded product. (4) Measurement of rubber particle morphology The shape of rubber particles was measured by the ultrathin section method of TEM (transmission electron microscope). (5) Measurement of Rubber Particle Average Diameter A pellet of the molded article 2 before molding was taken by an electron micrograph by an ultrathin section method, and the minor axis and major axis of 500 to 700 rubber particles in the photograph were measured, The average value was used as the particle diameter, and the volume average diameter was determined by the following formula. Volume average diameter = ΣnD ⁴ / ΣnD ³ (where n is the number of rubbers having a particle diameter Dμm.) Reference Example 74.5 parts by weight of styrene, 25.5 parts by weight of acrylonitrile, 25 parts by weight of ethylbenzene, rubber-like polymer ( Styrene-butadiene block copolymer solution viscosity 10 ct
s 5% styrene solution 25 ° C.) 12 parts by weight, organic peroxide [1,1-bis (t-butylperoxy) 3,3,3
5-trimethylcyclohexane] 0.04 part by weight and a mercaptan 0.2 part by weight were prepared as a raw material solution. This raw material was polymerized in a three-stage stirred polymerization tank array reactor. The raw material solution was continuously supplied from the first-stage tank. The reaction temperature in the first tank is 100 ℃, and in the second tank is 120 ℃,
In the third tank, the temperature was 130 ° C. The polymerization liquid was introduced from the third tank to a separation and recovery process consisting of a preheater and a decompression chamber. The average temperature (T _av ) of the resin at the outlet of the separation and recovery process is set to 240
A part of the resin discharged from the recovery step was injection-molded (molded product 1) at a temperature variation rate (T _de ) of 8% and a variation frequency (N) of 10 times per hour at 10 ° C. The surface of the obtained molded product was observed with an electron microscope. With the extruder A shown in Table 1, the resin discharged from the separation / recovery step was adjusted to a cylinder temperature of 23 at a kneading zone of 30% and a screw rotation speed of 3.3 rps.
After being treated at 0 ° C. without adding water, injection molding was performed. Table 2 shows the results. The temperature (T ₁ ) at the entrance of the kneading zone was 240 ° C. The gloss of the molded product 2 is 21%, which is almost the same as that of the molded product 1 and has a good matting property. The temperature fluctuation rate and the temperature fluctuation rate per hour were adjusted by the average temperature and flow rate of the heating medium in the jacket of the preheater. The pellets used in this experiment were mixed for 3 hours and used.

Example A-1 The resin discharged from the recovery step was heated at a cylinder temperature of 230 ° C.
Then, a resin was produced under the same conditions as in the reference example except that the rotation speed of the screw was set to 4.8 rps to obtain a molded product 2. The temperature (T ₁ ) at the entrance of the kneading zone was 235 ° C. The gloss of the molded product 2 was 30%, which was improved.

Example A-2 Same as Reference Example except that 1% by weight of water was added to the amount of resin extruded in the extruder and the cylinder temperature was 225 ° C. Table 2 shows the results. T ₁ was 230 ° C. The gloss was 33.2%, which was further improved.

Example A-3 Same as Reference Example except that the amount of water added was 7% by weight and the cylinder temperature was 160 ° C. in the extruder. Table 2 shows the results
Shown in T ₁ was 177 ° C. The gloss was 42%, which was further improved.

Example A-4 Same as Reference Example except that the screw rotation speed of the extruder was 6.0 rps, the amount of water added in the extruder was 1% by weight, and the cylinder temperature was 225 ° C. Table 2 shows the results. T
₁ was 233 ° C. The gloss was 38%, which was improved.

Comparative Example B-1 Same as Example A-2 except that the resin from the recovering step was treated with extruder B shown in Table 1. Table 2 shows the results.
The gloss of the obtained molded product 2 was 21%, and the gloss was hardly improved.

Comparative Example B-2 Same as Example A-3 except that the resin from the recovery step was treated with extruder B shown in Table 1. Table 2 shows the results. The gloss of the obtained molded product 2 was 22%, and the gloss was hardly improved.

Comparative Example B-3 The procedure of Example A-4 was repeated, except that the resin from the recovery step was treated with the extruder B shown in Table 1. Table 2 shows the results. The gloss of the obtained molded product 2 was 21%, and the gloss was hardly improved. In this way, the uniaxial full flight screw hardly changes the gloss even if the shear index is changed.

Example C-1 20 parts by weight of ethylbenzene, 10 parts by weight of rubber-like polymer
And 0.03 part by weight of organic peroxide, the same as in Reference Example
The average value of the recovery temperature (T _AV)
235 ° C, temperature fluctuation rate 2%, number of fluctuations per hour
Cylinder temperature in the extruder is 4 times and 220
The other conditions were the same as those in Example A-2. The results are shown in Table 3.
You T₁Was 223 ° C. The gloss of the obtained molding is
Molded product 1 is 75%, molded product 2 is 84.3%, and gloss
Has improved.

Example C-2 7% by weight of water was added in an extruder and the cylinder temperature was adjusted to 155.
Same as Example C-1 except that the temperature was set to be ° C. The results are shown in Table 3.
Shown in T ₁ was 158 ° C. The gloss of the obtained molded product was 89.4%, and the gloss was further improved.

Example C-3 10% by weight of water was added in an extruder, and the cylinder temperature was adjusted to 12.
Same as Example C-1 except that the temperature was 5 ° C. The results are shown in Table 3. T ₁ was 126 ° C. The gloss of the obtained molded product was 95.3%, which was further improved.

Example C-4 Same as Example C-1 except that the screw speed of the extruder was 6.0 rps. The results are shown in Table 3. T ₁ was 225 ° C. The resulting molded product has a light flux of 85.5.
% And the gloss improved.

Comparative Example D-1 Polybutadiene Latex (rubber particle diameter 0.3 μm) 2
80 parts by weight of a monomer mixture consisting of 70% styrene and 30% acrylonitrile was emulsion polymerized in the presence of 0 part by weight. The obtained graft copolymer was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain an ABS resin.
The obtained resin was compressed into a cylinder 240 by an extruder C shown in Table 1.
C., the screw rotation speed was 1.5 rps, and the molten resin was fed into the extruder A and treated under the same conditions as in Example C-1. The results are shown in Table 3 with molding 1 of the resin before treatment by the extruder C and molding 2 as the molding after treatment with the extruder A. When the temperature at the inlet of the kneading zone of the extruder A is T ₁ , T ₁ was 224 ° C. The gloss of the molded product 1 was 78%, and the gloss of the molded product 2 was 78%, which was unchanged.

Comparative Example D-2 The same as Comparative Example D-1 except that 7% by weight of water was added to the extruder A and the cylinder temperature was 155 ° C. The results are shown in Table 3. The gloss of the molded product 2 was 78.3%, which was hardly improved.

Comparative Example D-3 The same as Comparative Example D-4 except that the screw rotation speed of the extruder A was 6 rps. The results are shown in Table 3. T ₁ was 225 ° C. The gloss of the molded product 2 is 78%, which is hardly improved. In emulsion-polymerized ABS, the gloss cannot be controlled even by using a twin-screw extruder having a different shear index.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

INDUSTRIAL APPLICABILITY According to the method of the present invention, the rubber particle morphology on the surface of the molded product can be freely changed.
The characteristics of the surface of the S resin can be expressed very easily, and for example, gloss and matte can be controlled arbitrarily.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Morita 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Kagaku Co., Ltd. (72) Masato Takahisa 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Kagaku Incorporated (72) Inventor Tomofumi Shirato 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Chemical Co., Ltd.

Claims (8)

[Claims] 1. A rubber comprising: [I] a raw material containing at least a styrene-based monomer, an acrylonitrile-based monomer, and a rubber-like polymer is supplied to a polymerization step, and a part or all of the monomer is polymerized. After the step of polymerizing the polymer including forming the polymer particles (rubber particles), the mixed solution containing the polymer, the unreacted monomer and / or the solvent is heated, and simultaneously or after heating, introduced into a decompression chamber. It has a separation and recovery step of separating the monomer and / or the solvent from the resin component, and 0.5-1. Rubber particles present at a depth of 5 μm have a ratio a / b of the major axis a to the minor axis b of 1.5 or less when observing a plane parallel to the surface of the molded article with an electron micrograph by the ultrathin section method. A,
And at least two types of particles B having a ratio a / b of the major axis a to the minor axis b of 5 or more and the total area of the rubber particles observed by an electron micrograph by the ultrathin section method is 10
The area of particles A is at least 10% or more when 0%,
The ABS resin in which the area of the particles B is 0.01 to 90%,
[II] After the separation and recovery step, the surface of the obtained molded product (molded product 2) is subjected to shearing by a shearing by a twin-screw extruder having a kneading disk or a rotor, that is, molding is performed in the same manner as above. 0.5 to 1.5 μm from the object surface
The parallel plane of the depth of B is observed by an electron micrograph by the ultrathin section method, and the area of the particle B is the particle B observed in the molding 1.
The method for producing an ABS resin having various surface morphologies, wherein the ratio is controlled to be 0 to 95% when the ratio is 100%. 2. A rubber obtained by supplying a raw material containing [I] at least a styrene-based monomer, an acrylonitrile-based monomer, and a rubber-like polymer to a polymerization step and polymerizing a part or all of the monomer. After the step of polymerizing the polymer including particle formation, the mixed solution containing the polymer, the unreacted monomer and / or the solvent is heated, and at the same time or after the heating, the mixture is introduced into a decompression chamber so as to introduce the monomer and / or the solvent. From the surface of a molded product (molded product 1) obtained by injection-molding the resin exiting this separation and recovery process.
Rubber particles present at a depth of 5 μm have a ratio a / b of the major axis a to the minor axis b of 1.5 or less when observing a plane parallel to the surface of the molded article with an electron micrograph by the ultrathin section method. A,
And at least two types of particles B having a ratio a / b of the major axis a to the minor axis b of 5 or more and the total area of the rubber particles observed by an electron micrograph by the ultrathin section method is 10
The area of particles A is at least 10% or more when 0%,
The ABS resin in which the area of the particles B is 0.01 to 90%,
[II] A twin-screw extruder having a kneading disk or a rotor after leaving the separation and recovery step, and water is added to the resin between the outlet of the separation and recovery step and the portion where the kneading disk or rotor is installed. There is a portion to be added and a portion to evaporate the added water, and the portion to evaporate the added water is sheared using an extruder provided at the same time as the portion where the kneading disk is installed or immediately before that. Molded product obtained by giving (molded product 2)
In the same manner as above, i.e.
Parallel planes with a depth of ˜1.5 μm are observed with an electron micrograph by an ultrathin section method, and the area of the particles B is 0 to 95% when the ratio of the particles B observed in the above-mentioned molded article 1 is 100%. A method for producing an ABS resin having various surface morphologies, which is characterized by controlling so that 3. The method for producing an ABS resin according to claim 2, wherein the proportion of water added is 0 to 15 parts by weight per 100 parts by weight of the resin extruded per unit time. 4. The method according to claim 1, wherein the temperature of the extruder cylinder is reduced by 0 to 60% of the resin temperature at the exit of the recovery step at the portion where the kneading disk is installed in the extruder or immediately before that. A characterized by the temperature
Manufacturing method of BS resin. 5. The method according to claim 2, wherein the temperature of the extruder cylinder is lowered by 0 to 60% of the resin temperature at the exit of the recovery step at the portion where the kneading disk is installed in the extruder or immediately before that. A characterized by the temperature
Manufacturing method of BS resin. 6. The method according to claim 1, wherein the ratio L of the screw length (L) of the extruder to the cylinder diameter (D) is L.
/ D is 10 to 50 and a kneading zone uses a twin screw extruder having a screw effective length of 5 to 60%, a method for producing an ABS resin. 7. The extruder used in the method according to claim 1 or 2, wherein the screw element having a ratio D / d of the cylinder diameter (D) to the groove depth (d) of the screw element is 3 to 12, A method for producing an ABS resin, which comprises occupying a segment of 40 to 95% of the effective length of the screw. 8. A twin-screw extruder equipped with the kneading disc or rotor according to claim 1 or 2, which is a co-rotating intermeshing twin-screw extruder and has a shear index S represented by the following formula of 20. A method for producing an ABS resin having various surface morphologies, which is used under the condition of 300 to 300. γ _m = (dNE + DNE) × π × N / {(DB-dN
E) / 2} dNE: Minor axis of kneading disc (mm) DNE: Major axis of kneading disc (mm) N: Screw rotation number per second (rps) DB: Cylinder diameter (mm) S = (350 −T ₁ ) × 0.02 × γ _m × (θ / 60)
X L / 100 T ₁ : Resin temperature at the inlet of the kneading zone (° C) θ: Residence time of resin in the extruder (sec) L: Ratio of kneading zone to effective screw length (%)