JP2001163929A - Rubber-containing styrenic resin and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber-containing styrene resin wherein rubber particles dispersed in a styrene resin is controlled with respect to the morphology and particle thereof. SOLUTION: The rubber-containing styrene resin has particles of a rubber component dispersed in a matrix constituted of a styrene resin wherein a graft ratio of a styrene monomer to the rubber component is 1 or over, an average particle size of the dispersed rubber component ranges from 0.1 to 3 μm and a requirement for the following equation (1) is satisfied Mn=aT+b (1) (wherein Mn is a number average molecular weight of the matrix resin, T is a conversion of the styrene monomer, a is a constant larger than 0 and b is a constant not smaller than 0). The rubber component may be made of a butadiene rubber or the like. The particle size distribution of the dispersed rubber component may, for example, be in a two-peak form. Such a styrene resin can be prepared by polymerizing at least a styrene monomer in the presence of the rubber component at a graft ratio of 1 or over under conditions where the relation between the conversion Y of the styerene monomer and the number average molecular weight Mn of the polymer can be approximately expressed by a simple equation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-containing styrenic resin capable of controlling the particle morphology and particle size of a dispersed rubber component and a method for producing the same.

[0002]

2. Description of the Related Art As means for improving the impact resistance of a styrene resin, a styrene resin containing a rubber component (styrene-butadiene rubber, polybutadiene rubber, etc.) (for example, impact-resistant polystyrene HIPS, etc.) has been proposed. I have. In order to improve the impact resistance, a method of increasing the diameter of the dispersed rubber particles of HIPS or increasing the rubber content is often employed. However, although the impact resistance of the molded article is improved to some extent by these methods, the surface gloss of the molded article is reduced. On the other hand, to improve the surface gloss of molded products,
When the particle diameter of the rubber component is reduced or the rubber content is reduced, the impact resistance is reduced. For this reason, it is impossible to achieve a high level of both appearance characteristics and impact resistance.

As a method for improving appearance properties such as surface gloss and impact resistance, it is conceivable to control the form (particle form) of a rubber component dispersed in a resin in a particulate form. For example, in order to improve the surface gloss of a styrene resin, it is useful to make the microdomain structure a core / shell structure having a small particle diameter. However, in order to obtain a styrene resin having a core / shell structure morphology,
It is necessary to efficiently disperse the rubber component in the styrene resin matrix, and the usable rubber component (for example, a rubber component having high compatibility with the styrene resin (such as styrene-butadiene rubber)) is limited, and a general-purpose diene rubber is used. Cannot be used to obtain a styrene resin having a core / shell structure. Further, when a diene rubber is used, the morphology becomes a salami structure having a large particle diameter, and the surface gloss of a molded product cannot be improved.

In order to improve impact resistance while improving surface gloss, it has been proposed to use a small particle core / shell structure HIPS and large particle salami structure HIPS together. However, in this method, since the polymerization conditions are unique and a blending step is required, the work process becomes complicated.

On the other hand, there is known a living radical polymerization method in which living polymerization in which the primary structure (eg, molecular weight, molecular weight distribution, etc.) of a polymer is easily controlled is combined with radical polymerization which is hardly affected by impurities or solvents. . In the living radical polymerization method, even in the case of radical polymerization, the molecular weight can be controlled and a polymer having a narrow molecular weight distribution can be obtained.

[0006] Japanese Patent Publication No. 5-6537 discloses an initiator compound used for living radical polymerization of an unsaturated monomer. JP-A-6-199916 discloses a method for polymerizing a thermoplastic resin having a narrow polydispersity by heating a free radical initiator, a stable free radical acting agent and a polymerizable monomer compound.

Further, JP-A-8-239434 discloses a method for producing a composition containing a vinyl aromatic polymer and a rubber by polymerizing a vinyl aromatic monomer in the presence of a rubber component. The presence of stabilized free radicals in the polymerization stage is described. However, in this method, the effect of improving the impact resistance to the amount of rubber used, that is, the rubber efficiency is low.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rubber-containing or rubber-modified styrenic resin in which the form and particle size of the dispersed rubber can be easily controlled according to the application, and a method for producing the same. is there.

Another object of the present invention is to provide a rubber-containing or rubber-modified styrenic resin capable of achieving both high surface gloss and high impact resistance, and a method for producing the same.

It is still another object of the present invention to provide a rubber-containing or rubber-modified styrenic resin having excellent rubber efficiency and a method for producing the same.

Another object of the present invention is to provide a rubber-containing or rubber-modified styrenic resin having a core / shell microdomain structure even when the rubber component is a diene rubber such as polybutadiene, and a process for producing the same. .

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, when a styrene monomer is subjected to radical polymerization by a specific method in the presence of a rubber component, The present inventors have found that the form and particle size of the dispersed rubber and the molecular weight of the styrene resin constituting the matrix can be controlled, and have completed the present invention.

That is, the present invention relates to a rubber-containing styrene resin in which a rubber component is dispersed in a matrix composed of a styrene resin, wherein the graft ratio of the styrene monomer to the rubber component is 1%. As described above, the average particle diameter of the dispersed rubber component is 0.1 to 3 μm, and the condition of the following formula (1) is satisfied.

Mn = aT + b (1) (where, Mn is the number average molecular weight of the matrix resin, T is the conversion of the styrene monomer, a is a constant larger than 0, b
Represents a constant of 0 or more. The graft ratio may be about 1 to 5 or 2 or more. The average particle diameter of the rubber component is 0.1 to 3 μm
(For example, about 0.5 to 3 μm).

The styrenic monomer can be selected from styrene, vinyltoluene, α-methylstyrene and the like. The matrix may be composed of a graft copolymer of a styrene monomer and a copolymerizable vinyl monomer. The weight average molecular weight Mw of the matrix is 100,
It may be about 000 to 500,000.

The rubber component may be a diene rubber (for example, a butadiene rubber such as a diene rubber). The content of the rubber component may be about 1 to 20% by weight. The particle size distribution of the dispersed rubber component may be, for example, multimodal (in the particle size distribution, the dispersed rubber component has a plurality of peaks, particularly a bimodal shape having two peaks). The dispersion state may be monomodal, and the morphology (microdomain structure) may be, for example, a salami structure, a core / shell structure, or a mixture of these structures. The present invention relates to a styrene-based resin in which a rubber component is dispersed in a particle form in a matrix composed of a styrene-based resin, and the graft ratio of the styrene-based monomer to the rubber component is 2.5 or more, and the dispersed rubber A rubber-containing styrenic resin having an average particle diameter of the components of 0.3 to 3 μm is also included.

In the present invention, at least a styrene monomer may be used in the presence of a rubber component under the condition that the relationship between the conversion T of the styrene monomer and the number average molecular weight Mn of the polymer can be approximated by a linear equation. The present invention also includes a method for producing a rubber-containing styrenic resin in which the product is polymerized at a graft ratio of 1 or more. The polymerization may be carried out in the presence of a polymerization initiator and at least one additive selected from hydroxyamines, nitroso compounds and nitrone compounds represented by the following formulas (2) to (4).

[0018]

Embedded image

(Wherein R ^{1 to} R ⁵ are the same or different,
It represents a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, an alkenyl group, a cycloalkyl group, an aryl group or an aralkyl group. R ¹ and R ² , and R ⁴ and R ⁵ may combine with each other to form a ring. R ³ may be a group represented by the following formula (3a). )

[0020]

Embedded image

[0021] (wherein, R ^3a to R ^3c are the same or different, .R ^3a represents a hydrogen atom, an alkyl group or an aryl group
At least two of R ^3c may combine with each other to form a ring. ) The ratio of the additive to the polymerization initiator is the former / the latter (molar ratio)
= About 0.01 / 1 to 100/1.

In this specification, the acrylic monomer and the methacrylic monomer are referred to as “(meth) acrylic monomers”.
Collectively.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The rubber-containing styrene-based resin of the present invention comprises a matrix composed of a styrene-based resin and a rubber component dispersed in the matrix, and a graft ratio of the styrene-based monomer to the rubber component. Is 1 or more.

The styrene resin of the matrix can be composed of a styrene monomer alone or a copolymer, a copolymer of a styrene monomer and a copolymerizable vinyl monomer, or the like.

Examples of the styrene monomer include styrene, alkylstyrene [monoalkylstyrenes (vinyltoluenes (eg, o-, m-, p-methylstyrene)), ethylstyrene, p-isopropylstyrene, butylstyrene, and the like. alkyl-substituted styrenes such as pt-butyl styrene (C _1-4 alkyl styrene and the like); dialkyl styrenes (di C _1-4 alkyl styrene such as 2,4-dimethyl styrene); α-alkyl-substituted styrene (Eg, α-C _1-2 alkylstyrene such as α-methylstyrene and α-methyl-p-methylstyrene)], and alkoxystyrene (eg, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, p -t- butoxy C _1-4 alkoxy styrene such as styrene), halostyrenes (e.g. o-, m- and p
-Chlorostyrene, p-bromostyrene, etc.), styrenesulfonic acid or an alkali metal salt thereof, and the like. These styrene monomers can be used alone or in combination of two or more. Preferred styrene monomers include styrene, vinyltoluene, α-methylstyrene and the like, and styrene is particularly preferred.

As the copolymerizable vinyl monomer, for example,
α, β-unsaturated nitrile [(meth) acrylonitrile,
Halogenated (meth) acrylonitrile (p-chloro (me
T) vinyl cyanide compounds such as acrylonitrile)
, Etc.), α, β-unsaturated carboxylic acid esters (especially
Alkyl ester) [alkyl (meth) acrylate
(Meth) such as cyclohexyl (meth) acrylate
Acrylic acid C_5-7Cycloalkyl ester; (meth) a
(Meth) acrylic acid C such as phenyl acrylate _6-12Ants
Ester such as benzyl (meth) acrylate
T) Acrylic acid C_7-14Aralkyl esters; or these
Maleate corresponding to the (meth) acrylate
Or dialkyl esters, mono- or dialky fumaric acid
Esters or itaconic acid mono- or dialkyl esters
And vinyl ester-based monomers [vinyl carboxylate
Ter, for example, vinyl formate, vinyl acetate, propionic acid
C such as vinyl and vinyl pivalate_1-10Carboxylic acid vinyl
Ester (especially C_1-6Carboxylic acid vinyl ester)
Etc.], a hydroxyl group-containing monomer [hydroxyethyl
(Meth) acrylate, hydroxypropyl (meth) a
(Hydroxyalkyl (meth) acrylic such as acrylate
Rate (eg, hydroxy C_1-10Alkyl (meth) a
Acrylate, preferably hydroxy C_1-4Alkyl (me
Acrylate)), glycidyl group-containing monomer
[Glycidyl (meth) acrylate, etc.], carboxy
Group-containing monomer [α, β-
Saturated monocarboxylic acid; maleic acid, fumaric acid, itacone
Α, β-unsaturated polycarboxylic acids such as acids;
Acid anhydrides (eg, maleic anhydride, fumaric anhydride, etc.)
), Etc.), and an amino group-containing monomer [N, N-dimethylamine]
Minoethyl (meth) acrylate, N, N-diethyla
Minopropyl (meth) acrylate, etc.)
[(Meth) acrylamide or derivatives thereof
(For example, N-methyl (meth) acrylamide,
N, N-dimethyl (meth) acrylamide, N-methylo
(Meth) acrylamide) or these
Corresponding fumaric acid amides (fumaric acid, fumaric acid
Acid or their derivatives), etc.]
N-C such as reimide and N-methylmaleimide_1-4Al
Kill ester, N-phenylmaleimide, etc.), conjugated di
Ene monomers [butadiene, isoprene, chloroprene
, Neoprene, 1,3-pentadiene, 1-chlorobutane
Tadiene, 2,3-dimethyl-1,3-butadiene, 3
-Butyl-1,3-octadiene, phenyl-1,3-
C such as butadiene_4-16Diene (preferably C_4-10Jie
Olefin-based monomers [ethylene, pro
C such as pyrene, butene (such as isobutene)_2-10Arche
(Preferably C_2-6Alkenes, etc.)
Vinyl (vinyl fluoride, vinyl chloride, vinyl bromide, iodine
Vinylidene halide), vinylidene halide (vinylidene fluoride)
Den, vinylidene chloride, vinylidene bromide, vinylid iodide
Den etc.). The (meth) acrylic acid
Alkyl esters include methyl (meth) acrylate,
Ethyl (meth) acrylate, Buty (meth) acrylate
, T-butyl (meth) acrylate, (meth) acrylic
Hexyl acid, octyl (meth) acrylate, (meth) a
2-ethylhexyl acrylate, laurate (meth) acrylate
(Meth) acrylic acid C such as ril_1-20Alkyl ester
(Preferably (meth) acrylic acid C_1-14Alkyl esthetic
Le) is included.

Preferred vinyl monomers are (meth) acrylic monomers [(meth) acrylic acid, (meth) acrylic acid esters (particularly methyl methacrylate, acrylic acid C
_2-10 alkyl esters), (meth) acrylonitrile and the like].

These vinyl monomers can be used alone or in combination of two or more. The use amount of these copolymerizable monomers can be selected, for example, in the range of 0 to 50% by weight, preferably about 0 to 30% by weight.

The weight average molecular weight Mw of the styrene resin matrix resin is 100,000 to 500,000,
It is about 150,000 to 300,000. Mw
Is less than 100,000, the rigidity is poor, and 500,000
If it exceeds 300, the fluidity may be reduced and the moldability may be reduced.

Examples of the rubber component include various rubbery polymers (such as diene rubbers such as butadiene rubber and isoprene rubber, styrene-butadiene rubber, styrene-diene copolymer rubber such as styrene-isoprene rubber, ethylene-vinyl acetate copolymer, and the like). Acrylic rubber, ethylene-propylene rubber (EPDM), etc.) can be used. Preferred rubber components are diene rubber components (for example, butadiene, isoprene, 2-chloro-1,3-butadiene, 1-chloro-
Conjugated 1,3-diene rubber such as 1,3-butadiene or a derivative thereof). A particularly preferred rubber component is a butadiene rubber (a diene rubber such as a butadiene rubber). These rubber components can be used alone or in combination of two or more.

The weight average molecular weight of the rubber component is 1 × 10 ⁴
About 2 × 10 ⁶ , preferably 5 × 10 ⁴ to 1 × 1
0 ⁶ mm, more preferably 1 × 10 ⁵ ~5 × 10 about ^5.

Examples of the rubber-modified styrene resin include impact-resistant polystyrene (HIPS), styrene-butadiene-
Styrene (SBS resin), styrene-isoprene-styrene (SIS resin), acrylonitrile-butadiene-
Styrene copolymer (ABS resin), acrylonitrile
Acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylene-propylene rubber-styrene copolymer, acrylonitrile-EPDM-styrene copolymer (AES resin), methyl methacrylate-butadiene-
A styrene copolymer (MBS resin) can be exemplified. Particularly, HIPS, ABS resin and the like are preferable.

In the rubber-modified styrenic resin, the content of a rubber component such as polybutadiene is 1 to 20% by weight (for example, 3 to 20% by weight), preferably 2 to 15% by weight.
(For example, 5 to 15% by weight). When the content of the rubber component is less than 1% by weight, the impact resistance is practically insufficient, and when it exceeds 20% by weight, both the surface gloss and the rigidity are likely to be reduced.

The rubber-containing styrenic resin of the present invention has a high surface gloss even if the particle size of the dispersed rubber is large, and the rubber content is at least excellent in impact resistance, so that the rubber component can be effectively used ( High rubber efficiency). This is due to the high graft ratio.

The graft ratio (g value) is a ratio (weight ratio) of the styrene monomer grafted on the rubber component to the rubber component. Specifically, 1 g of the styrene resin is
Mixed solvent [methyl ethyl ketone / acetone (1/1 v
/ V)] was dissolved in 35 mL, and the weight fraction (solid basis) of the insoluble matter obtained by centrifugation was measured for the gel content and the rubber content fraction in 1 g of the rubber-containing styrene-based resin measured by an iodination titration method. The rubber content is represented by the following formula.

Graft ratio = [gel content (g) -rubber content (g)] / rubber content (g) The g value is an index indicating the degree of grafting of the styrene monomer to the rubber component, and is 1 or more. (For example, 2 or more), preferably 1 to 5, more preferably 1.5 to 3
(For example, 2-3). If the g value is less than 1, the ratio of the styrene monomer grafted to the rubber content is low, so that the rubber efficiency is reduced and the impact resistance is reduced. On the other hand, if the g value exceeds 5, the rigidity is reduced and the balance of physical properties is practically insufficient.

In the rubber-containing styrene resin, the rubber component is dispersed in the styrene resin matrix in the form of particles.

The particle size of the rubber component dispersed in the styrenic resin matrix affects both the surface gloss and the impact resistance of the styrenic resin. The particle diameter of the dispersed rubber was determined by taking a transmission electron micrograph of a styrene resin using an ultrathin section, measuring the circle-converted particle diameter of 1000 rubber-like polymer particles, and using the following formula: average particle diameter = ( ^{_{Σn i D i 4) / (}} Σn i D i 3) ( wherein, n _i is converted to circle diameter D _i ([mu] m) can be calculated as the average particle diameter using a represents the number of rubbery polymer having a) .

The average particle size of the dispersed rubber is 0.1 to 3 μm.
m, preferably 0.3 to 2 μm, more preferably 0.1 μm.
It is about 3 to 1.5 μm, usually about 0.2 to 2 μm. If the average particle size is less than 0.1 μm, the impact resistance is reduced, and if it is more than 3 μm, the surface gloss is reduced.

The rubber-containing styrenic resin of the present invention can provide a high-gloss molded article probably because of a high graft ratio even if the average particle size of the dispersed rubber is relatively large. For example, the average particle size is 0.3 to 2 μm (for example, 0.5 to 2 μm).
２2 μm), preferably 0.4-1.5 μm, 0.5-
Even with a thickness of about 1.2 μm, a high gloss molded product can be obtained.

The morphology (morphology) of the dispersed rubber particles (the microdomain structure of the rubber-containing styrene resin) has a core / shell structure (eg, a structure in which a single styrene resin phase is included in one rubber particle). And a salami structure (for example, a structure in which a plurality of styrene-based resin phases are included in one rubber particle and each styrene-based resin phase is partitioned by a rubber phase), and the like. May be.

In the core / shell structure, the average particle size of the dispersed rubber component is 0.1 to 1 μm, preferably 0.2 to 1 μm.
It is about 0.8 μm, and more preferably about 0.3 to 0.7 μm. In the present invention, even when a diene rubber (such as polybutadiene) is used, the core having such a small average particle diameter is used.
A styrene-based resin having a shell structure is obtained, and 90% by volume or more, preferably 9% by volume, of the dispersed rubber particles.
When the content is 5% by volume or more and the inclusion occlusion is 3 or less, a uniform and fine rubber-containing styrene resin can be obtained. Since a core / shell structure can be formed with inexpensive butadiene rubber, a styrene-based resin having excellent surface gloss can be produced at low cost. With a core / shell structure, not only gloss but also transmittance is good, and transparency seems to be high.

Further, in the present invention, as described later, since rubber particles can be formed with a relatively low-viscosity polymerization solution, not only the core / shell structure having a relatively small average particle diameter as described above but also the particle diameter Can be stably formed even in the case of a large particle core / shell structure, which has been considered difficult to maintain. In the large particle core / shell structure, the average particle diameter of the dispersed rubber component is 0.5 to 3 μm, preferably 0.7 to 2.5 μm.
It is about. A resin having a large particle size core / shell structure has high gloss and excellent impact resistance, and can be used as a base resin for alloys.

In the salami structure, the average particle size of the dispersed rubber component is 0.3 to 3 μm, preferably 0.5 to 2.5 μm.
μm (for example, 0.7 to 2.5 μm).

The particle size distribution of the dispersed rubber component may be monomodal, and may have a bimodal structure [for example, when the particle size distribution is 2
The particle size distribution of the dispersed rubber component may have a plurality of peaks, such as a peak-like structure (for example, a structure in which rubber particles having the core / shell structure and the salami structure are mixed)].

The rubber-containing styrenic resin having a bimodal structure has excellent impact resistance as compared with a monomodal styrene-based resin having a core / shell structure, and has a surface gloss substantially equal to that of the monomodal resin. It is.

When the microdomain structure has a salami structure or a bimodal structure, it can be used for high gloss applications by further controlling the particle size, and can improve rubber efficiency and reduce costs.

In the case of having a bimodal structure, the particle size distribution of the dispersed rubber particles may be, for example, 0.1 to 1 for the average particle size.
a rubber particle having a core / shell structure and a salami structure rubber particle (salami structure rubber particles having an included occlusion amount of 3 or less) having a core / shell structure having a particle size of about 0.1 μm (preferably 0.1 to 0.5 μm); It may be bimodal with salami structure rubber particles in a range of (preferably 1 to 3 μm). When the average particle diameter of the small particles is less than 0.1 μm or the average particle diameter of the large particles is less than 0.5 μm, the impact resistance is not sufficient, and the average particle diameter of the small particles exceeds 1 μm or the average particle of the large particles If the diameter exceeds 5 μm, the surface gloss decreases. In particular, when the average particle size on the large particle side is out of the above range, the influence on impact resistance and surface gloss is large.

In the rubber-containing styrenic resin having a bimodal structure, the above conditions can be appropriately adjusted so that small particles and large particles of the rubber component can be mixed at a desired ratio.
Although the ratio is not particularly limited, for example, the ratio between the small particle rubber and the large particle rubber is the former / the latter = 40/60 to 95
/ 5 (volume ratio), preferably 60/40 to 90/10
(Volume ratio). If the ratio is less than 40/60, the surface gloss may be impaired, and if it exceeds 95/5, the impact resistance may be reduced. Therefore, the surface gloss and the impact resistance are imparted at a high level in a well-balanced manner. Can not do.

The volume ratio between the large-particle rubber and the small-particle rubber in the bimodal structure is calculated from a circle-converted particle diameter calculated for 1000 or more rubber-like polymer particles randomly extracted from a transmission electron micrograph. , The volume of each of the large-particle rubber and the small-particle rubber was determined, and the volume was calculated from the respective numbers of the large-particle rubber and the small-particle rubber and the volume using the following equation. Note that core / shell structure rubber particles and salami structure rubber particles (particles having an included occlusion amount of 3 or less) having a particle diameter of about 0.1 to 1 μm are referred to as small particle rubber, and a particle diameter of about 1 to 5 μm is used. The rubber particles having a salami structure were defined as large particle rubber.

Volume ratio = Σp _i V _i / Σq _i W _i (where p _i represents the number of small-particle rubber-like polymers having volume V _i , and q _i is large-particle rubber-like polymer having volume W _i In the present invention, the g value is 2.5 or more (for example, 2.5 to
5), preferably as high as about 3 to 5 and the average particle diameter of the dispersed rubber component is 0.3 to 3 μm, preferably 0.4 to 2 μm
Also included are rubber-containing styrenic resins to a lesser extent. Also in such a styrene resin, a diene rubber (particularly polybutadiene) is preferable as a rubber component.

In the rubber-containing styrene resin of the present invention, the following formula (1) is provided between the number average molecular weight Mn of the styrene matrix resin and the conversion T of the styrene monomer.
There is a relationship represented by

Mn = aT + b (1) (where, Mn is the number average molecular weight of the matrix resin, T is the conversion of the styrene monomer, a is a constant greater than 0, b
Represents a constant of 0 or more. The number average molecular weight Mn is determined by gel permeation chromatography (GPC) measurement of a soluble component obtained by dissolving 1 g of the rubber-containing styrene resin in 35 mL of a mixed solvent [methyl ethyl ketone / acetone (1/1 v / v)]. The calculated number average molecular weight of the matrix resin is shown. That is, in the polymerization of the styrene-based monomer, there is a relationship that can approximate the conversion rate T of the styrene-based monomer and the number average molecular weight Mn of the styrene-based resin constituting the matrix by a linear equation. By controlling the molecular weight, the molecular weight of the matrix resin can be accurately controlled. In the above formula (1), the constants a and b plot the relationship between the number average molecular weight Mn and the conversion T, respectively, and show the slope and intercept of the approximated straight line.
Is 0 or more.

For this reason, the rubber-containing styrene-based resin can be used at least in the presence of a rubber component under the condition that the relationship between the conversion T of the styrene-based monomer and the number average molecular weight Mn of the polymer can be approximated by a linear equation. It can be produced by polymerizing a styrene monomer at a graft ratio of 1 or more.

The polymerization reaction is not limited to, for example, a batch type or a semi-batch type. Even when a polymerization is carried out in a continuous manner, the conversion and the number average at a plurality of points (for example, two points) in the polymerization process (or route). By measuring and extrapolating the molecular weight Mn, the relationship between the conversion and the number average molecular weight Mn can be approximated by a linear equation.

In the above polymerization, for example, when the conversion T of the styrene-based monomer is 10 to 80%, the Mn of the matrix resin is usually 20,000 to 300,000 (for example, 20,000 to 200, 200). 000), preferably M
n is about 50,000 to 200,000. If Mn (T) during phase inversion is less than 20,000, the dispersed rubber particles after phase inversion are unstable and it is difficult to maintain the particle diameter,
When Mn (T) at the time of phase inversion exceeds 200,000 or Mn (L) at the end of the reaction exceeds 300,000,
The viscosity of the polymerization system becomes too high, making it difficult to efficiently disperse the rubber component. The phase inversion refers to the generation of rubber particles from the liquid phase as the polymerization reaction proceeds, and the phase inversion refers to a conversion of about 10% (for example, 10 to 2%).
The completion of the reaction means about 70% (for example, about 60 to 90%) in terms of conversion, depending on conditions.

JP-A-6-199916 discloses that a mixture of a free radical initiator, a stable free radical acting agent and a polymerizable monomer such as styrene is heated.
It is described to obtain a thermoplastic resin. However, in this system, since the number average molecular weight at the beginning of polymerization is as small as about 2,000, it is difficult to disperse the rubber component into particles.

When polymerizing by the bulk polymerization method, the Mn of the matrix resin at the time of phase inversion (conversion rate is about 10 to 20%)
(T) is about 20,000 to 200,000, and Mn (L) of the matrix resin at the end of the reaction (conversion is about 60 to 90%) is about 50,000 to 300,000. When the number average molecular weight is within the above range, the particle size can be controlled in a suitable range, and a styrene resin having excellent impact strength can be obtained. Also, for example, Mn (L) is M
1.5 times or more (for example, about 1.5 to 15 times) of n (T), preferably 1.7 times or more (about 1.7 to 15 times)
It is. If Mn (L) is less than 1.5 times Mn (T), the particle size of the dispersed rubber may be too small to sufficiently improve the impact resistance. Further, even if the conversion is actually less than 60%, it is preferable that the above relationship be obtained by extrapolating an approximate expression (primary expression) obtained from the relationship between the conversion and the number average molecular weight.

For example, in a rubber-containing styrene resin having a bimodal microdomain structure, the aforementioned Mn (L) / Mn (T) is, for example, 1.5 to 15
Times, preferably about 1.7 to 15 times. Mn (L)
If / Mn (T) is less than 1.5, the bimodal structure may not be obtained. If it exceeds 15 times, the molecular weight of the matrix resin increases as the polymerization reaction proceeds, and the viscosity of the reaction system increases. As the nature decreases,
The fluidity and moldability of the obtained resin are reduced.

The microdomain structure of the rubber-containing styrenic resin has a tendency to have a core / shell structure when the rubber phase is thin and a graft reaction frequently occurs, as observed by an electron microscope. Etc.) to form a salami structure. Further, in the present invention, since the radical reaction proceeds by a specific method, the polymerization can be performed in a state where the viscosity of the polymerization system at the start of the polymerization is relatively lower than that of ordinary radical polymerization. Therefore, a core / shell structure can be obtained by increasing the shearing force.

A polymerization initiator may be added to the polymerization reaction. By adding the polymerization initiator, a higher g value can be obtained. Examples of the polymerization initiator include conventional initiators, for example, ketone peroxides such as cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; 2,2-bis (4,4-diene); -T-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl- Peroxyketals such as 4,4-bis (t-butylperoxy) valate; cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-
Hydroperoxides such as dihydroperoxide; di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α, α ′
-Dialkyl peroxides such as -bis (t-butylperoxy-m-isopropyl) benzene and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3; benzoyl peroxide, decanoyl peroxide Diacyl peroxides such as oxide, lauroyl peroxide, and 2,4-dichlorobenzoyl peroxide; peroxycarbonates such as bis (t-butylcyclohexyl) peroxydicarbonate; t-butylperoxybenzoate; Dimethyl-2,
Organic peroxides such as peroxyesters such as 5-di (benzoylperoxy) hexane, inorganic peroxides such as hydrogen peroxide and persulfates (such as potassium persulfate and ammonium persulfate), or mixtures thereof ( A substituted benzoyl peroxide mixture, for example, m-toluyl & benzoyl peroxide (trade name: Niper BMT-K4
0) etc.] can be used.

An azo compound or the like may be used as a polymerization initiator. Examples of the azo compound include azobisnitrile [for example, 2,2′-azobisbutyryl such as 2,2′-azobisisobutyronitrile (AIBN) and 2,2′-azobis (2-methylbutyronitrile). Ronitriles: 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-
2,2′-azobisvaleronitriles such as dimethylvaleronitrile); 2,2′-azobispropionitrile such as 2,2′-azobis (2-hydroxymethylpropionitrile); 1,1 ′ 1,1′-azobis such as azobis (cyclohexane-1-carbonitrile)
1-alkanenitrile, especially 1,1'-azobis-1
- cycloalkanes nitriles (e.g., 1,1'-azobis -1-C _5-8 cycloalkane nitrile); 4,4 '
Azobiscyanocarboxylic acids such as -azobis (4-cyanovaleric acid)], azonitrile [azobutyronitriles such as 2- (carbamoylazo) isobutyronitrile; 2-phenylazo-4-methoxy-2,4 -Azovaleronitriles such as dimethylvaleronitrile, etc.],
Azobisalkanes [eg, 2,2′-azobis (2-
Methylpropane), 2,2'-azobis (2,4,4-
2,2'-azobis C _3-10 such as trimethylpentane)
Alkanes], dimethyl 2,2′-azobisisobutyrate and the like.

These polymerization initiators can be used alone or in combination of two or more.

The ratio between the polymerization initiator and the styrene monomer is as follows: the former / the latter = 0.001 / 100 to 10/100
(Molar ratio), preferably 0.01 / 100 to 1/100
(Molar ratio). The ratio is 0.001 / 10
If it is less than 0 (molar ratio), the polymerization rate will decrease, and the g value will decrease. Or the ratio is 10/100
If the molar ratio is exceeded, the polymerization rate will be too high, making it difficult to control the polymerization reaction.

At the time of polymerization, an additive (or a control agent or a control compound) may be added to control the molecular weight or the like. The additive (control compound) is not particularly limited as long as it satisfies the primary formula.
Hydroxyamines, nitroso compounds, nitrone compounds, etc. represented by (4) are preferred.

[0066]

Embedded image

(Wherein R ^{1 to} R ⁵ are the same or different,
It represents a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, an alkenyl group, a cycloalkyl group, an aryl group or an aralkyl group. R ¹ and R ² , and R ⁴ and R ⁵ may combine with each other to form a ring. Examples of the alkyl group represented by R ^{1 to} R ⁵ include methyl, ethyl, propyl, isopropyl, 1-ethylpropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, t-pentyl, isopentyl, and hexyl. And a linear or branched C _1-10 alkyl group such as 1,1,1-diethylpropyl, octyl, isooctyl, and decyl.

Examples of the alkoxy group include C _1-10 alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, pentyloxy and hexyloxy.

Examples of the acyl group include C _2-10 acyl groups such as acetyl, propionyl, butyryl, isobutyryl, valeryl and hexanoyl.

Examples of the alkenyl group include C _2-10 alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 2-butenyl and 2-hexenyl.

The cycloalkyl group includes, for example,
And C _4-10 cycloalkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl (particularly C _5-8 cycloalkyl groups such as cyclopentyl group or cyclohexyl group). Examples of the aryl group include a C _6-10 aryl group such as a phenyl and naphthyl group. Examples of the aralkyl group include a C _6-10 aryl-C _1-4 alkyl group such as a benzyl, phenethyl and naphthylmethyl group.

In the formulas (2) to (4), R ¹ and R
² is preferably an alkyl group (C _1-6 alkyl group, especially
_1-4 such as an alkyl group), an alkoxy group (C _1-4 alkoxy group), an acyl group (C _1-4 acyl group) such as, R
³ is preferably (such as C _{6- 12} aryl group) an aryl group, (such as C _7-14 aralkyl group) aralkyl group or the following formula (3a):

[0073]

Embedded image

[0074] (wherein, R ^3a to R ^3c are the same or different, .R ^3a represents a hydrogen atom, an alkyl group or an aryl group
At least two of R ^3c may combine with each other to form a ring. ). R ^{3a to} R
^3c is preferably an alkyl group (such as a C _1-4 alkyl group)
It is.

R ⁴ and R ⁵ are preferably an alkyl group [C
_{A 1-10} alkyl group, preferably a C _1-8 alkyl group, more preferably a branched alkyl group such as a _{tC 4-8} alkyl group (particularly a t-butyl group)), an aryl group [C _6-12 aryl (Particularly, a phenyl group). Also, R ¹
And R ² , and R ⁴ and R ⁵ may be bonded to each other to form a ring (preferably a 4- to 8-membered ring);
At least two members out of R ^{3a to} R ^3c may be bonded to each other to form a ring (preferably a 4- to 8-membered ring), for example, a heterocyclic ring such as azetin, pyrroline, pyrrolenine, pyridine, azepine and azocine. . Preferred heterocycles are those containing a nitrogen atom as a heteroatom such as pyrroline and pyridine.
Or a 6-membered ring. The ring may be aromatic or non-aromatic, and may be a condensed ring (eg, quinoline, isoquinoline, indoline, etc.). The same or different carbon atoms constituting the ring may have one or more substituents, for example, an alkyl group (a C _1-4 alkyl group such as a methyl, ethyl, propyl, isopropyl, or butyl group).
Etc. may be substituted.

The groups R ^{1 to} R ⁵ may have a substituent. Examples of the substituent include an alkyl group (C _1-6 such as methyl, ethyl, propyl, isopropyl, butyl, etc.).
Alkyl group); a mono C _1-6 alkyl-substituted, such as N- monoalkyl-substituted amino group (e.g., methylamino group, ethylamino group, an amino group, an aryl group (phenyl, C _6-10 aryl group), such as a naphthyl group N, N-dialkyl-substituted amino group (di-C _1-6 alkyl-substituted amino group such as dimethylamino group and diethylamino group); acylamino (for example, C _1-6 acylamino group such as formylamino and acetylamino) A halogen atom; a halogenated alkyl group; a carbonyl group; a hydroxyl group.

The hydroxyamines (2) include
A kill group, an alkoxy group, an alkenyl group, an aryl group,
Hydroxy optionally having a substituent such as an aralkyl group
Luamine (eg, methylhydroxylamine, ethyl
C such as hydroxylamine _1-6Alkyl hydroxyl
C such as amine, methoxyhydroxylamine_1-6Al
Coxyhydroxylamine, phenylhydroxylamine
C such as_6-12N- such as arylhydroxylamine
Monosubstituted hydroxylamines; dimethylhydroxyl
Amine, diethylhydroxylamine, methylethylamine
Di-C such as droxylamine_1-6Alkyl hydroxyl
C such as amine, ethylmethoxyhydroxylamine
_1-6Alkyl-C_1-6Alkoxy hydroxylamine etc.
N, N-disubstituted hydroxylamine, etc.)
Hydroxylamines; N-hydroxy of aliphatic dicarboxylic acids
Droxyimide (N-hydroxysuccinimide, N-
Hydroxymaleimide, etc.), non-aromatic cyclic dicarbo
Acid N-hydroxyimide (N-hydroxytetrahi
Drophthalimide, N-hydroxyhexahydrophthale
Imides), bridged cyclic dicarboxylic acid imides (N-
Droxyhettimide, N-hydroxyhymic acid
Imide), aromatic dicarboxylic imide (N-hydro
Xyphthalimide, N-hydroxytrimellitic acid imi
, N-hydroxy-methylcyclohexentricarbo
Cyclic imides)
Can be exemplified. In particular, N, N-di C_1-4Alkyl hydro
Xylamine, aromatic dicarboxylic imide (N-hydro
And the like are preferred.

The hydroxyamines (2) can be used alone or in combination of two or more.

Examples of the nitroso compound (3) include nitrosoalkanes which may be substituted by the above substituent (for example, nitrosomethane, nitrosoethane, 1-nitrosopropane, 2-nitrosopropane, 2-nitrosobutane,
2-methyl-1-nitrosopropane, 2-methyl-2-
Nitrosopropane (BNO), 2-methyl-2-nitrosobutane, 3-methyl-3-nitrosopentane, 3-ethyl-3-nitrosopentane, 3-methyl-3-nitrosohexane, 3-ethyl-3-nitrosohexane , 3-
Nitroso C _1-10 alkanes such as ethyl-3-nitrosoheptane, 4-ethyl-4-nitrosoheptane and 4-propyl-4-nitrosoheptane (preferably nitroso C
_2-10 alkanes)); nitrosocycloalkanes (eg, nitroso C _4-8 cycloalkanes such as nitrosocyclopentane, nitrosocyclohexane, etc.); and optionally substituted nitrosobenzenes (nitrosobenzene (NB), Nitrosotoluene (o-, m-, p-form),
di-C _1-4 alkylamino-nitrosobenzene such as p-dimethylamino-nitrosobenzene (DMNA); and nitrosonaphthalene. Preferred N- substituted nitroso compounds, R ^3a ~ in the formula (3a)
Compounds in which at least two of R ^3c are the same or different and are alkyl groups (particularly C _1-3 alkyl groups), nitroso-t-alkanes (eg, 2-alkyl-2-nitrosopropane, etc.), nitrosobenzenes, etc. It is. These nitroso compounds (3) can be used alone or in combination of two or more.

The nitroso compound (3) can be used not only as a monomer but also as a dimer.

The nitrone compound (4) includes NC
_1-8 alkyl-α-C _1-8 alkyl nitrones (N-methyl-α-methyl nitrones, N-methyl-α-ethyl nitrones, etc.), N—C _1-8 alkyl-α-C _6-12 aryl nitrones (N-methyl-α-phenylnitrone, N-ethyl-α-phenylnitrone, N-isopropyl-α-phenylnitrone, N-isobutyl-α-phenylnitrone, Ns-butyl-α-phenylnitrone, N- t-
Butyl-α-phenyl nitrone (PBN), Nt-pentyl-α-phenyl nitrone, etc., N—C _1-10 alkyl-α-C _5-8 cycloalkyl nitrone (for example, N
-Isopropyl-α-cyclohexyl nitrone, N-isobutyl-α-cyclohexyl nitrone, Ns-butyl-α-cyclohexyl nitrone, Nt-butyl-α
-Cyclohexyl nitrone, Nt-pentyl-α-cyclohexyl nitrone, and other compounds corresponding to the above-mentioned N-alkyl-α-aryl nitrones), N-aryl-α
A chain nitrone compound such as an aryl nitrone (such as N-phenyl-α-phenyl nitrone); pyrroline-N-
Oxides (1-pyrroline-N-oxide, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO),
5,5-diethyl-1-pyrroline-N-oxide, 4,
4-diethyl-1-pyrroline-N-oxide, 3,3-
Dimethyl-1-pyrroline-N-oxide, etc.), pyrrole-N-oxide, pyridine-N-oxide (PO),
Examples thereof include cyclic nitrone compounds such as piperazine-N-oxide. In particular, NtC _4-8 alkyl-α, such as Nt-butyl-α-phenyl nitrone (PBN).
Preferred are pyrroline-N-oxides such as -aryl nitrones, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and pyridine N-oxide.

The nitrone compound (4) can be used alone or in combination of two or more.

These additives (2) to (4) can be used alone or in combination of two or more.

The ratio of the additive (control agent) to the polymerization initiator is the former / the latter (molar ratio) = 0.01 / 1 to 100 /
1, preferably 0.01 / 1 to 10/1, more preferably 0.1 / 1 to 10/1 (for example, 0.1 / 1 to 5 /
1), especially about 0.1 / 1 to 2/1. If the ratio is less than 0.01 / 1 (molar ratio), it becomes difficult to control the molecular weight, and if it exceeds 100/1 (molar ratio), the polymerization rate may decrease.

In Japanese Patent Application Laid-Open No. Hei 8-239434, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) is used as a free radical stabilizer corresponding to the additive of the present invention. But in this system g
The value is less than 1, and the rubber efficiency is low. In addition,
In JP 6537, a compound which generates a free radical having a polymerization initiation ability and a nitroxide group upon thermal decomposition is used as a reversible terminator in radical polymerization. However, in this system, it is difficult to efficiently control the molecular weight.

The polymerization method of the styrene-based monomer is not particularly limited, and a conventional polymerization method such as bulk polymerization, solution polymerization,
Suspension polymerization, emulsion polymerization, bulk-suspension polymerization and the like can be employed.

In particular, bulk polymerization or bulk-suspension polymerization in which a rubber component is dissolved in a styrene-based monomer and then bulk polymerization is performed, and if necessary, suspension polymerization is preferable. Also, the polymerization is
It can be started by applying heat, light, radiation, etc. to the system.

In the bulk polymerization method (bulk polymerization method) which is advantageous for industrial production, a solvent may be added. The solvent is not particularly limited, and a common solvent, for example, aromatic hydrocarbons (benzene, toluene, ethylbenzene,
Xylene, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aliphatic hydrocarbons (hexane, octane, etc.), ketones (methyl ethyl ketone, etc.), esters (ethyl acetate, etc.), ethers (1,4-dioxane, etc.)
And the like.

The amount of the solvent (solvent) used is, for example, 0 to 30% by weight, preferably 5 to 2% by weight, based on the whole reaction mixture.
It can be selected from a range of about 0% by weight. Solvent ratio is 30
If the content exceeds% by weight, economic efficiency such as solvent recovery may be reduced.

The polymerization can be carried out under normal pressure or under pressure.

The polymerization temperature can be selected from the range of about 80 to 180 ° C., preferably about 90 to 150 ° C., depending on the type of polymerization method, constitution of the polymerization initiator system, polymerization rate and the like. If the polymerization temperature is lower than 80 ° C., the productivity decreases. If the polymerization temperature exceeds 180 ° C., the molecular weight of the resin decreases, and the impact strength decreases.
There is a possibility that the reaction rate is increased and it becomes difficult to control the polymerization reaction.

The polymerization may be usually carried out in an atmosphere of an inert gas such as nitrogen, helium, argon or the like, for example, under a flow of an inert gas.

The polymerization can be carried out by any of a batch system, a semi-batch system, and a continuous system. For example, the polymerization is carried out by a multi-stage continuous polymerization method, a multi-stage continuous polymerization method, or a continuous polymerization method based on a combination thereof. You may.

According to the method of the present invention, the morphology of the rubber-containing styrenic resin can be easily and accurately controlled. For example, a rubber-containing styrene-based resin having a core / shell structure mainly has a condition in which a shear force efficiently acts on a rubber component, for example, a condition in which the molecular weight of a matrix resin is relatively high (a condition in which the viscosity difference from the rubber component is small). And shearing (stirring) until the conversion in the polymerization reaction becomes relatively high.
Can be prepared by adding (adding) a styrene-based monomer when the molecular weight of the matrix resin becomes relatively high. By selecting these conditions, the rubber-containing styrene-based resin can be prepared. Can have a monomodal particle size distribution of the rubber component. When a rubber-containing styrene-based resin having a core / shell structure is produced, polymerization is performed at an appropriate stirring speed (for example, about 70 to 100 rpm), and when the conversion of the styrene-based monomer becomes about 25 to 50%. To lower the stirring speed (for example, 15 to 30 r
pm), and may be further polymerized, and the polymerization may be continued after the viscosity of the polymerization system is once decreased by adding a styrene monomer or the like. When a styrene-based monomer is not added, a rubber-containing styrene-based resin having a morphology of a salami structure can be obtained.

The rubber-containing styrenic resin having a bimodal structure containing both a salami structure and a core / shell structure is used under conditions that reduce the shearing force on the rubber component, for example, when the molecular weight of the matrix resin is relatively low ( It can be prepared by lowering the shear rate relatively early under conditions in which the viscosity difference from the rubber component is large) or by adding a styrene monomer at a stage where the molecular weight of the matrix resin is low. When producing a rubber-containing styrene resin having a bimodal structure, for example, polymerization is performed at an appropriate stirring speed (for example, about 70 to 100 rpm), and the conversion of the styrene monomer becomes about 20 to 40%. At this point, the stirring speed is reduced (for example, about 15 to 30 rpm), and the mixture may be further polymerized.
After once lowering the viscosity of the polymerization system, the polymerization may be continued.

When the styrene monomer is added, the relationship between the conversion rate T ₁ of the styrene monomer before addition and the molecular weight Mn ₁ of the matrix resin and the conversion of the styrene monomer after the addition are added. The timing and amount of addition are not particularly limited as long as the relationship between the ratio T ₂ and the molecular weight Mn ₂ of the matrix resin can be approximated by linear equations. The addition amount is, for example, 5 to 50% by weight of the total amount of the styrene monomer, for example, 10 to 4%.
It is about 0% by weight.

As described above, by appropriately adjusting the above conditions, a resin having a salami structure or a core / shell structure can be produced depending on the application, or a resin having a bimodal structure having a core / shell structure and a salami structure can be prepared. You can adjust the ratio. That is, the microdomain structure of the rubber-containing styrene-based resin (the form (shape) or particle diameter of the dispersed rubber particles) can be controlled by the method of the present invention.

The rubber-containing styrenic resin obtained by the above method is diluted with a solvent, if necessary, for example, after the polymerization reaction, and precipitated in a poor solvent, or volatile components such as monomers and solvents are removed. It may be separated and purified by removing it.

The rubber-containing styrenic resin of the present invention may contain conventional additives such as stabilizers (antioxidants (phenolic antioxidants, phosphorus antioxidants, etc.), ultraviolet absorbers, heat stabilizers, etc.). ], Flame retardants, lubricants (zinc stearate, calcium stearate, ethylene bisstearyl amide, etc.), release agents, antistatic agents, fillers, coloring agents (titanium oxide, red iron, azo, perylene, phthalocyanine, complex) A coloring agent such as a ring system), a plasticizer and a spreading agent (eg, polyethylene glycol, mineral oil, etc.) may be added.

The rubber-containing styrenic resin of the present invention may be used as a resin composition (polymer blend or polymer alloy) in combination with various resins (thermoplastic resin, thermosetting resin, thermoplastic elastomer, etc.). For example, the rubber-containing styrene resin of the present invention and a polystyrene resin may be melt-kneaded and used as a polymer blend, and resins other than polystyrene (for example, styrene-
Butadiene rubber, polyphenylene ether, polycarbonate, polyester, etc.) or melt-kneaded, and used as a polymer blend.

[0101]

According to the present invention, since radical polymerization is carried out by a specific method to obtain a rubber-containing styrenic resin, the form and particle size of the dispersed rubber can be easily controlled according to the application, and the rubber efficiency is high and styrene is high. The surface gloss and impact resistance of the resin can be improved to a high level. The styrene resin has excellent surface gloss even if the particle diameter is large, and has excellent impact resistance even if the rubber content is low. In the present invention,
Even when a diene rubber is used as the rubber component, the microdomain structure of the rubber-containing styrene-based resin can have a core / shell structure.

[0102]

The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

The operations in the following Examples and Comparative Examples were performed in the case where the content was 20% with a stirrer unless otherwise specified.
The reaction was carried out under a nitrogen stream using a polymerization apparatus in which a liter reactor and a twin-screw extruder equipped with a devolatilizer were connected.

The Izod impact strength, rigidity, surface appearance, polymerization rate, molecular weight, constants a and b, and the content of particles having a core / shell structure of the styrene resins obtained in Examples and Comparative Examples were measured by the following methods. did. [Izod impact strength] Measured according to JIS K7710. [Stiffness (flexural modulus)] Measured according to JIS K7203. [Surface appearance (gloss)] Gloss (gloss) at an incident angle of 60 ° was measured according to JIS K7105. [Polymerization rate (conversion rate)] The monomer remaining in the reaction solution obtained by the polymerization reaction is subjected to gas chromatography (GC, Inc.).
It was quantified by an internal standard method (internal standard reagent: dimethylformamide) using Shimadzu Corporation, column: PEG20M), and the amount of reduction of the monomer was calculated as a conversion rate into a polymer (polymerization rate). [Molecular weight] During phase inversion (conversion rate of matrix resin is 10 to 10)
The number average molecular weights Mn (T) and Mn (L) and the weight average molecular weight (Mw) at the end of the reaction (about 20%) and at the end of the reaction (the conversion rate of the matrix resin is about 60 to 90%) are determined by gel permeation chromatography ( Shimadzu Corporation
Manufactured under the following conditions.

Column: Shodex K-806L, 3 in series Solvent: THF Column temperature: 40 ° C. Detector: Differential refractometer (RI) Flow rate: 0.8 mL / min [Constants a and b] The constants a and b are as follows: It was calculated from the obtained number average molecular weight Mn and the conversion according to the above formula (1). [Content of Core / Shell Structure Particles (Small Particles)] A transmission electron micrograph of the composition was taken using an ultra-thin section, and the content of the included occlusion was not more than 3 out of about 1,000 rubber-like polymer particles. % (Volume%) of the particles was calculated.

Example 1 1.3 kg of polybutadiene (manufactured by Asahi Kasei Kogyo Co., Ltd., diene 35A), 150 mmol of polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 75 mmo
l of an additive (diethylhydroxylamine, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in 150 mol of a styrene monomer, and the raw material solution was charged into a reactor. After performing polymerization at 95 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion was about 30%, the stirring speed was reduced to 20 rpm to continue the polymerization. When the conversion exceeded 70%, unreacted monomers were removed at 230 ° C. using an extruder with a devolatilization function. . The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Example 2 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 75 mmol of a polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 37.5 mm
ol of an additive (diethylhydroxylamine, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in 100 mol of a styrene monomer, and this raw material solution was charged into a reactor. After performing polymerization at 95 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion was about 40%, 50 mol of styrene monomer was added. When the conversion of the entire polymerization system reached about 40% again, the stirring speed was reduced to 20 rpm to continue the polymerization,
When the conversion exceeded 70%, the unreacted monomer was removed at 230 ° C. using an extruder with a devolatilization function. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Example 3 1.3 kg of polybutadiene (manufactured by Asahi Kasei Kogyo Co., Ltd., diene 35A), 100 mmol of a polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 50 mmo
1 additive (2-methyl-2-nitrosopropane, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 150 mol of a styrene monomer, and this raw material solution was charged into a reactor. Stirring speed 8
After polymerization at 95 ° C. for 3.5 hours at 5 rpm, 1
The temperature was raised to 30 ° C., and the polymerization was further continued. About 30% conversion
At this point, the stirring speed was reduced to 20 rpm to continue the polymerization, and when the conversion exceeded 70%, the unreacted monomer was removed at 230 ° C. using an extruder with a devolatilization function. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Comparative Example 1 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 150 mmol of a polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 180 mm
ol TEMPO (Aldrich) 150mo
and dissolved in 1 styrene monomer, and this raw material solution was charged into the reactor. 2. Stirring speed at 95 rpm at 85 rpm
After the polymerization was performed for 5 hours, the temperature was raised to 130 ° C., and the polymerization was further continued. When the conversion is about 30%, the stirring speed is increased to 20 rpm.
m, and the polymerization was further continued. When the conversion exceeded 70%, an unreacted monomer was removed at 230 ° C. using an extruder with a devolatilization function. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Comparative Example 2 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 15 mmol of polymerization initiator (manufactured by NOF CORPORATION, Niper BMT-K40) and 45 mmol
Of TEMPO (manufactured by Aldrich) was dissolved in 150 mol of styrene monomer, and this raw material solution was charged into a reactor. After performing polymerization at 95 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion was about 30%, the stirring speed was reduced to 20 rpm to continue the polymerization. When the conversion exceeded 70%, unreacted monomers were removed at 230 ° C. using an extruder with a devolatilization function. . The melted strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

COMPARATIVE EXAMPLE 3 1.3 kg of a styrene-butadiene copolymer rubber (NS-312, manufactured by Nippon Zeon Co., Ltd.) and 15 mmol of a polymerization initiator (Perbutyl Z, manufactured by NOF Corporation) were mixed for 150 m.
styrene monomer, and this raw material solution was charged into a reactor. Polymerization was performed at 110 ° C. with a stirring speed of 20 rpm. When the conversion is about 40%, the stirring speed is reduced to 1
0 rpm, and the polymerization was further continued.
%, Use an extruder with a devolatilization function,
Unreacted monomers were removed at 0 ° C. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Example 4 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 200 mmol of a polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 100 mm
ol of an additive (diethylhydroxylamine, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in 150 mol of a styrene monomer, and this raw material solution was charged into a reactor. After performing polymerization at 95 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion was about 30%, the stirring speed was reduced to 20 rpm to continue the polymerization. When the conversion exceeded 70%, unreacted monomers were removed at 230 ° C. using an extruder with a devolatilization function. . The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Example 5 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 100 mmol of a polymerization initiator (manufactured by NOF Corporation, Niper BMT-K40) and 50 mmol
(A product of Daicel Chemical Industries, Ltd., diethylhydroxylamine) was dissolved in 100 mol of a styrene monomer, and this raw material solution was charged into a reactor. Stirring speed 8
After polymerization at 95 ° C. for 3.5 hours at 5 rpm, 1
The temperature was raised to 30 ° C., and the polymerization was further continued. About 30% conversion
At this point, 50 mol of the monomer was added. When the conversion of the entire polymerization system becomes 30% again, the stirring speed is set to 20 rpm.
Then, polymerization was continued, and when the conversion exceeded 70%, an unreacted monomer was removed at 230 ° C. using an extruder with a devolatilization function. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.
Shown in

Example 6 1.3 kg of polybutadiene (manufactured by Asahi Chemical Industry Co., Ltd., diene 35A), 328 mmol of polymerization initiator (manufactured by NOF Corporation, Niiper BMT-K40) and 328 mm
ol of an additive (diethylhydroxylamine, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in a mixture of 50 mol of acrylonitrile monomer and 87 mol of styrene monomer, and this raw material solution and 3.25 kg of ethylbenzene were charged into a reactor. After performing polymerization at 80 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion of the entire polymerization system reached about 40%, the stirring speed was reduced to 25 rpm to continue the polymerization. When the conversion exceeded 65%, the extruder with a devolatilization function was used. The monomer in the reaction was removed. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

Example 7 1.3 kg of polybutadiene (manufactured by Asahi Kasei Corporation, diene 35A), 328 mmol of a polymerization initiator (manufactured by NOF CORPORATION, Niper BMT-K40) and 820 mm
ol of an additive (Diethylhydroxylamine, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in a mixture of 50 mol of an acrylonitrile monomer and 87 mol of a styrene monomer, and this raw material solution and 3.25 kg of ethylbenzene were charged into a reactor. After performing polymerization at 80 ° C. for 3.5 hours at a stirring speed of 85 rpm, the temperature was increased to 130 ° C., and the polymerization was further continued. When the conversion of the entire polymerization system reached about 40%, the stirring speed was reduced to 25 rpm to continue the polymerization. When the conversion exceeded 65%, the extruder with a devolatilization function was used. The monomer in the reaction was removed. The molten strand was extruded from an extruder, cooled and cut to obtain a pellet-shaped sample. Table 1 shows the results of measuring the physical properties of this sample.

In the table, Mn (T) and Mn (L) are the values at the time of phase inversion (when the conversion of the styrene monomer is 10%).
%) And at the end of the reaction (conversion of the styrene monomer is 70%).
%), The number average molecular weight of the matrix resin and Mw indicate the weight average molecular weight of the obtained pellet.

[0117]

[Table 1]

(In the table, * indicates the numerical value before addition of the monomer in the upper row, and the numerical value after addition of the monomer in the lower row. ** indicates the average particle diameter of the small particles in the bimodal structure, and the parenthesized value indicates the abundance rate. (Volume% of small particle rubber in the whole rubber-like polymer) is shown. *** indicates the content (volume%) of particles having 3 or less included occlusions.) As is clear from the tables, in all the examples, the particle diameter of the dispersed rubber particles was 3 μm. Compared with Comparative Example 1 and Comparative Example 2 where the g value is less than 1, the Izod impact strength, the flexural modulus and the glossiness are excellent, and even if the particle diameter is small, the impact resistance is high and the rubber efficiency is high. Further, the cores of Examples 1 and 2 /
The rubber-containing styrene-based resin having a shell structure has a larger dispersed rubber particle diameter and higher impact resistance than Comparative Example 3 using styrene-butadiene rubber, but has the same glossiness.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoko Yanagita 780-16 F-term (reference) 4J002 BN141 BN151 BN161 4J026 AA11 AA12 AA13 AA38 AA67 AA68 AA69 BA05 BA06 BA08 BA09 BA27 BA31 DB12 DB26 GA01 GA03 GA04

Claims (21)

[Claims] 1. A rubber-containing styrene-based resin in which a rubber component is dispersed in a matrix composed of a styrene-based resin, wherein the graft ratio of the styrene-based monomer to the rubber component is 1 or more, and The average particle size of the components is 0.
A rubber-containing styrene-based resin having a thickness of 1 to 3 μm and satisfying the following condition (1). Mn = aT + b (1) (where, Mn is the number average molecular weight of the matrix resin, T is the conversion of the styrene monomer, a is a constant larger than 0, b
Represents a constant of 0 or more. ) 2. The rubber-containing styrenic resin according to claim 1, wherein the graft ratio is from 1 to 5. 3. The rubber-containing styrenic resin according to claim 1, wherein the graft ratio is 2 or more and the average particle size of the rubber component is 0.1 to 3 μm. 4. The rubber-containing styrene resin according to claim 1, wherein the styrene monomer is at least one selected from styrene, vinyltoluene and α-methylstyrene. 5. A matrix comprising a styrene monomer and
α, β-unsaturated nitrile, α, β-unsaturated carboxylic acid ester, vinyl ester monomer, hydroxyl group-containing vinyl monomer, glycidyl group-containing vinyl monomer, carboxyl group or acid anhydride group-containing vinyl Monomer, amino group-containing vinyl monomer, amide vinyl monomer, imide vinyl monomer, conjugated diene monomer, olefin monomer,
2. The rubber-containing styrenic resin according to claim 1, comprising a graft copolymer with at least one copolymerizable vinyl monomer selected from vinyl halide and vinylidene halide. 6. The weight average molecular weight Mw of the matrix is as follows:
The rubber-containing styrenic resin according to claim 1, which has a molecular weight of 100,000 to 500,000. 7. The rubber composition according to claim 1, wherein the rubber component is a diene rubber.
The rubber-containing styrenic resin according to the above. 8. The rubber-containing styrene resin according to claim 1, wherein the rubber component is a butadiene rubber. 9. The rubber-containing styrenic resin according to claim 1, wherein the content of the rubber component is 1 to 20% by weight. 10. The number average molecular weight Mn (T) at the time of phase inversion is 2
The rubber-containing styrenic resin according to claim 1, wherein the number-average molecular weight Mn (L) at the end of the reaction is from 50,000 to 300,000. 11. The dispersed rubber component has an average particle size of 0.1 to 0.1.
The rubber-containing styrenic resin according to claim 1, which has a microdomain structure of (1) a core / shell structure or (2) 90% or more of the dispersed rubber particles and 3 or less inclusion occlusions. 12. The dispersion rubber component has an average particle size of 0.5 to 0.5.
2. The rubber-containing styrenic resin according to claim 1, which has a diameter of 3 μm and a microdomain structure of a core / shell structure. 13. The rubber-containing styrenic resin according to claim 1, wherein the particle size distribution of the dispersed rubber component is bimodal. 14. A styrene-based resin in which a rubber component is dispersed in a matrix composed of a styrene-based resin, wherein the graft ratio of the styrene-based monomer to the rubber component is 2.5 or more. The average particle size of the components is 0.3
A rubber-containing styrene-based resin having a size of about 3 μm. 15. The rubber-containing styrenic resin according to claim 6, wherein the rubber component is a diene rubber and the microdomain structure is a core / shell structure. 16. The number average molecular weight Mn (T) at the time of phase inversion is 2
000 to 200,000, the number average molecular weight Mn (L) at the end of the reaction is 50,000 to 300,000,
When the ratio of Mn (L) to Mn (T) is Mn (L) / Mn
2. The rubber-containing styrenic resin according to claim 1, wherein (T) = 1.5 to 15. 17. The grafting ratio of at least a styrene monomer in the presence of a rubber component under the condition that the relationship between the conversion rate T of the styrene monomer and the number average molecular weight Mn of the polymer can be approximated by a linear equation. A method for producing a rubber-containing styrenic resin polymerized by one or more. 18. The method for producing a rubber-containing styrenic resin according to claim 17, wherein a rubber-containing styrenic resin having a rubber component having an average particle diameter of 0.1 to 3 μm dispersed therein is obtained. 19. A polymerization initiator, and a compound represented by the following formula (2):
18. The production method according to claim 17, wherein the polymerization is carried out in the presence of at least one additive selected from hydroxyamines, nitroso compounds and nitrone compounds represented by (4). Embedded image (Wherein, R ^{1 to} R ⁵ are the same or different and each represent a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group.
R ¹ and R ² , and R ⁴ and R ⁵ may combine with each other to form a ring. R ³ may be a group represented by the following formula (3a). ) (Wherein, R ^{3a to} R ^3c are the same or different and are each a hydrogen atom,
It represents an alkyl group or an aryl group. Of R ^{3a to} R ^3c ,
At least two may combine with each other to form a ring. ) 20. The method according to claim 1, wherein the additive is N, N-diC _1-4 alkylhydroxylamine, aromatic dicarboxylic imide,
In a), a compound in which at least two of R ^{3a to} R ^3c are the same or different and are alkyl groups, nitroso-t-alkanes, nitrosobenzenes, dimers of nitrone compounds, NtC _4-8 alkyl-α -Aryl nitrones,
20. The rubber-containing styrene resin according to claim 19, which is at least one selected from pyrroline-N-oxides and pyridine-N-oxides. 21. The rubber-containing styrene resin according to claim 19, wherein the ratio of the additive to the polymerization initiator is the former / the latter (molar ratio) = 0.01 / 1 to 100/1.