JP2017133040A - Heat resistant styrene resin composition, extrusion sheet and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat resistant styrene resin composition excellent in heat resistance, mechanical strength, appearance and moldability, a non-foaming and foaming extrusion sheet and molded article formed by using the heat resistant styrene resin composition.SOLUTION: There are provided: a heat resistant styrene resin composition containing a predetermined amount of copolymer resin (a) which is a styrene-methacrylic acid-methyl methacrylate copolymer and a predetermined amount of MBS resin (b) by grafting a copolymer mainly containing a methyl methacrylate monomer unit and a styrene monomer unit to a rubbery particle consisting of a butadiene monomer unit and/or a copolymer resin (c) which is a maleated styrene-ethylene-butylene-styrene block copolymer, wherein the copolymer resin (a) contains a styrene monomer unit, a methacrylic acid monomer unit and a methyl methacrylate monomer unit at a specific ratio, and a Vicat softening temperature of the heat resistant styrene resin composition is 106°C or more; and a non-foaming and foaming extrusion sheet and molded article formed by using the resin composition.SELECTED DRAWING: None

Description

  The present invention relates to a heat-resistant styrene resin composition excellent in heat resistance, mechanical strength, appearance, and moldability, and a non-foamed and foamed extruded sheet and molded article formed using the heat-resistant styrene resin composition About.

  Styrene-methacrylic acid resin is excellent in heat resistance and relatively inexpensive, so it can be used for food containers such as lunch boxes and prepared dishes, packaging materials, foam boards for thermal insulation of houses, and diffusion of liquid crystal televisions containing diffusing agents. Widely used for plates and the like. In recent years, in order to popularize microwave ovens used for business, such as convenience stores, and shorten the usage time of microwave ovens, higher output devices (which are likely to become hot in a short time) have been used. For this reason, a resin having higher heat resistance and excellent moldability is desired. Resin with improved mechanical strength such as brittleness compared to conventional products due to the complexity of the shape due to the design and the increase in the size of the container due to the increase in contents in food containers such as bento and side dishes Is desired.

  Generally, in a styrene-methacrylic acid resin, it is necessary to increase the content of methacrylic acid in order to obtain a resin having higher heat resistance. In this case, a gelled product due to methacrylic acid is likely to be generated, and an appearance defect may be observed on the sheet surface. This phenomenon is particularly seen when exfoliating in vacuum from an extruder vent to remove moisture and low molecular residual volatiles during non-foamed sheet extrusion. An increase in methacrylic acid also leads to a decrease in mechanical strength. Regarding the method for producing a styrene-methacrylic acid resin, the following Patent Document 1 describes a method of adding 2-ethyl-hexyl alcohol to a polymerization raw material liquid, and the following Patent Document 2 describes a polymerization raw material liquid. A method of adding octyl alcohol is described.

  In addition, in the styrene-methacrylic acid-based resin, a method of adding a styrene-based resin containing a rubbery component has been implemented for the purpose of improving mechanical strength such as brittleness, but improvement of mechanical strength is insufficient. is there. For example, Patent Document 3 below describes a heat-resistant foamed sheet obtained by adding impact-resistant polystyrene (HIPS) as a styrene copolymer containing a rubbery component. Patent Documents 4 and 5 listed below describe a laminated foam sheet for forming a microwave oven container and a heat-resistant styrene-based resin composition to which high impact styrene is added as a rubber component.

JP 09-87332 A JP 2006-282963 A Japanese Patent Laid-Open No. 02-58548 JP-A 63-264335 JP2012-207201A

  However, in the above-described conventional method for producing a styrene-methacrylic acid resin, the effect of suppressing gelation is not sufficiently exhibited, and the mechanical strength of the obtained resin is not sufficient. Therefore, there is a need for a non-foamed or foamed molded article that is formed using a resin composition that is more difficult to gel and is excellent in heat resistance, mechanical strength, appearance, and moldability.

  Under such circumstances, the problem to be solved by the present invention is formed using a heat-resistant styrene resin composition excellent in heat resistance, mechanical strength, appearance, and moldability, and the heat-resistant styrene resin composition. Non-foamed and foamed extruded sheets and molded articles.

In light of the above problems, the present inventors have conducted extensive research and repeated experiments. As a result, conventional styrene-methacrylic acid, and further, a copolymer resin having a specific composition of styrene-methacrylic acid-methyl methacrylate, and a reinforcing agent. MBS resin (b) obtained by grafting a specific resin, that is, a rubber-like particle comprising a butadiene monomer unit with a copolymer having methyl methacrylate monomer units and styrene monomer units as main components, and A heat-resistant styrene-based resin composition having specific heat resistance is obtained by using a resin obtained by mixing a copolymerized resin (c) that is a maleated styrene-ethylene-butylene-styrene block copolymer at a specific ratio. And, if necessary, by further adjusting the concentration of residual styrene monomer, styrene dimer and styrene trimer in the resin composition to a specific range. A heat-resistant styrenic resin composition having mechanical strength and appearance that could not be achieved by the resin of the prior art is obtained, and an excellent non-foamed and foamed molded product is obtained from the heat-resistant styrenic resin composition. As a result, the present invention was completed.
That is, the present invention is as follows.

[1] A copolymer resin (a) which is a styrene-methacrylic acid-methyl methacrylate copolymer, and a rubber-like particle comprising a butadiene monomer unit, a methyl methacrylate monomer unit and a styrene monomer unit. Heat-resisting containing one or both of an MBS resin (b) obtained by grafting a copolymer having a main component as a main component and a copolymer resin (c) which is a maleated styrene-ethylene-butylene-styrene block copolymer A styrenic resin composition comprising:
Content of the said copolymer resin (a) is 85-99 mass% with respect to 100 mass% of total mass of the said copolymer resin (a), the said MBS resin (b), and the said copolymer resin (c). And the total content of the MBS resin (b) and the copolymer resin (c) is 1 to 15% by mass,
When the copolymer resin (a) has a total content of styrene monomer units, methacrylic acid monomer units, and methyl methacrylate monomer units of 100% by mass, the styrene monomer unit is 69%. -96 mass%, and 4-16 mass% of methacrylic acid monomer units, and 0-15 mass% of methyl methacrylate monomer units,
The heat-resistant styrene resin composition, wherein the Vicat softening temperature of the heat-resistant styrene resin composition is 106 ° C or higher.
[2] The total amount of residual styrene dimer and styrene trimer is 0.6% by mass or less, and the residual amount of styrene monomer is based on the total mass of the heat-resistant styrene-based resin composition. The heat-resistant styrene-based resin composition according to [1], which is 700 ppm or less.
[3] The heat-resistant styrenic resin composition according to the above [1] or [2], wherein the copolymer resin (a) has a weight average molecular weight of 100,000 to 350,000.
[4] The butadiene monomer unit content in the MBS resin (b) is 50% by mass or more, and the mass composition ratio of methyl methacrylate and styrene in the MBS resin (b) is 30/70 to 70. The heat-resistant styrene-based resin composition according to any one of [1] to [3], which is / 30.
[5] The heat-resistant styrene-based resin composition according to any one of the above [1] to [4], wherein the styrene monomer unit content in the copolymer resin (c) is 10 to 50% by mass.
[6] The rubber-modified styrene resin (d) is further contained in an amount of 30% by mass or less with respect to 100% by mass of the total mass of the heat-resistant styrene resin composition,
The rubber content in the rubber-modified styrenic resin (d) is 7 to 15% by mass,
The heat-resistant styrene resin composition according to any one of [1] to [5], wherein the rubber-modified styrene resin (d) has a rubber particle diameter of 0.5 to 5.0 μm.
[7] The rubber-modified styrene-based resin (d) has a toluene insoluble matter swelling index of 8.0 to 14.0, and a mass ratio of the toluene insoluble matter to the rubber content in the toluene insoluble matter (toluene) The heat-resistant styrene-based resin composition according to the above [6], wherein the rubber content in the insoluble content / toluene insoluble content is 1.5 to 4.0.
[8] A copolymer resin (e) having a weight average molecular weight of 1,000,000 or more, which is a copolymer of a methyl methacrylate monomer unit and a butyl acrylate monomer unit, is used as the heat-resistant styrene resin. The heat-resistant styrene-based resin composition according to any one of [1] to [7], further contained in an amount of 3.0% by mass or less with respect to 100% by mass of the total mass of the composition.
[9] An aliphatic primary alcohol having a freezing point of −10 ° C. or lower and a carbon number of 14 or more is added to a total of 100 components other than the aliphatic primary alcohol in the heat-resistant styrenic resin composition. The heat-resistant styrene-based resin composition according to any one of [1] to [8], further contained in an amount of 0.02 to 1.0 part by mass with respect to part by mass.
[10] A non-foamed extruded sheet formed using the heat-resistant styrenic resin composition according to any one of [1] to [9].
[11] A foamed extruded sheet formed using the heat-resistant styrene-based resin composition according to any one of [1] to [9].
[12] A molded article formed using the non-foamed extruded sheet according to [10] or the foamed extruded sheet according to [11].

  According to the present invention, a heat-resistant styrene resin composition excellent in heat resistance, mechanical strength, appearance, and moldability, a non-foamed and foamed extruded sheet formed using the heat-resistant styrene resin composition, and A molded article can be provided.

Hereinafter, the present invention will be described in detail.
[Heat-resistant styrene resin composition]
The heat-resistant styrene resin composition of the present invention comprises a copolymer resin (a) which is a styrene-methacrylic acid-methyl methacrylate copolymer, and a methyl methacrylate monomer on rubber-like particles comprising a butadiene monomer unit. An MBS resin (b) obtained by grafting a copolymer mainly composed of a unit and a styrene monomer unit, and a copolymer resin (c) which is a maleated styrene-ethylene-butylene-styrene block copolymer One or both of the heat-resistant styrenic resin compositions, wherein the copolymer resin (a), the MBS resin (b), and the copolymer resin (c) with respect to a total mass of 100% by mass, The content of the copolymer resin (a) is 85 to 99% by mass, and the total content of the MBS resin (b) and the copolymer resin (c) is 1 to 15% by mass. a) is still When the total content of the monomer unit, the methacrylic acid monomer unit, and the methyl methacrylate monomer unit is 100% by mass, the styrene monomer unit is contained by 69 to 96% by mass, and methacrylic acid Heat-resistant styrene containing 4 to 16% by weight of monomer units and 0 to 15% by weight of methyl methacrylate monomer units, and having a Vicat softening temperature of 106 ° C. or higher of the heat-resistant styrene-based resin composition Based resin composition (hereinafter sometimes simply referred to as “resin composition of the present invention”).

<Copolymer resin (a)>
The content of the copolymer resin (a) which is a styrene-methacrylic acid-methyl methacrylate copolymer is 100 mass% in total mass of the copolymer resin (a), the MBS resin (b) and the copolymer resin (c). On the other hand, it is 85-99 mass%, Preferably it is 87-98 mass%, More preferably, it is 89-97 mass%. If this content is less than 85% by mass, the amount of MBS resin (b) and / or copolymer resin (c) used will increase, making it difficult to foam due to outgassing during foam molding, and the properties of the resulting foam. Tends to decrease. Moreover, there exists a tendency for the rigidity of the obtained molded article to fall and the external appearances, such as a sheet | seat, to fall. On the other hand, if it exceeds 99% by mass, the amount of MBS resin (b) and / or copolymer resin (c) used is reduced, and the effect of improving the mechanical strength cannot be sufficiently obtained.

  In the copolymer resin (a), when the total content of the styrene monomer unit, the methacrylic acid monomer unit, and the methyl methacrylate monomer unit is 100% by mass, Content is 69-96 mass%, Preferably it is 74-92 mass%, More preferably, it is the range of 77-88 mass%. If the content is less than 69% by mass, the fluidity of the resin is lowered. On the other hand, if it exceeds 96% by mass, the desired amount of methacrylic acid monomer units described below and optionally methyl methacrylate monomer units are present. Therefore, the effects described below with these monomer units cannot be obtained.

  In the resin composition of the present invention, the methacrylic acid monomer unit plays a role of improving heat resistance. Content of methacrylic acid monomer unit when the total content of styrene monomer unit, methacrylic acid monomer unit and methyl methacrylate monomer unit of copolymer resin (a) is 100% by mass Is 4 to 16% by mass, preferably 6 to 14% by mass, and more preferably 9 to 13% by mass. If this content is less than 4% by mass, the effect of improving the heat resistance is insufficient. On the other hand, if it exceeds 16% by mass, the gelled product in the resin increases, resulting in poor appearance, and the fluidity of the resin is reduced. And a decrease in mechanical properties is not preferable.

  In general, styrene-methacrylic acid-based resins including styrene-methacrylic acid-methyl methacrylate copolymer resins are mostly produced by radical polymerization on an industrial scale, but are described in the aforementioned Patent Documents 1 and 2. As described above, in order to suppress the gelation reaction in the devolatilization step, various alcohols may be added to the polymerization system for polymerization.

  In the production of the resin composition of the present invention, methyl methacrylate is used for suppressing the dehydration reaction of methacrylic acid by intermolecular interaction with methacrylic acid and for improving the mechanical strength of the resin. Furthermore, the addition of methyl methacrylate contributes to the improvement of resin properties such as weather resistance and surface hardness.

  When the total content of the styrene monomer unit, the methacrylic acid monomer unit, and the methyl methacrylate monomer unit is 100% by mass, the content of the methyl methacrylate monomer unit is 0 to 15% by mass. Preferably, it is 2-12 mass%, More preferably, it is the range of 3-10 mass%. When this content exceeds 15% by mass, the fluidity of the resin tends to decrease and the water absorption tends to increase, such being undesirable.

  In addition, when methacrylic acid and methyl methacrylate are bonded side by side, if a high-temperature, high-vacuum devolatilizer is used, a methanol removal reaction may occur depending on conditions, and a six-membered cyclic acid anhydride may be formed. . The copolymer resin (a) according to the present invention may contain this six-membered cyclic acid anhydride, but it is preferably less because the fluidity is lowered.

  The content of the styrene monomer unit, the methacrylic acid monomer unit, and the methyl methacrylate monomer unit in the copolymer resin (a) according to the present invention is measured by proton nuclear magnetic resonance (1H-NMR), respectively. It can be obtained from the integral ratio of the spectrum measured with a machine.

  The copolymer resin (a) further contains a monomer unit other than the styrene monomer unit, the methacrylic acid monomer unit, and the methyl methacrylate monomer unit as long as the effects of the present invention are not impaired. Typically but not excluded, it consists of a styrene monomer unit, a methacrylic acid monomer unit, and a methyl methacrylate monomer unit.

  In the present invention, the weight average molecular weight of the copolymer resin (a) is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, still more preferably 140,000 to 250,000. is there. When the weight average molecular weight is 100,000 to 350,000, a resin excellent in balance between mechanical strength and fluidity can be obtained, and there is little mixing of gel. In the present disclosure, the weight average molecular weight is a value obtained in terms of standard polystyrene using gel permeation chromatography.

  The melt flow rate at 200 ° C. of the copolymer resin (a) is preferably 0.3 to 3.0, more preferably 0.4 to 2.5, and still more preferably 0.4 to 2.0. Can do. When the melt flow rate is 0.3 or more, it is preferable from the viewpoint of fluidity, and when it is 3.0 or less, it is preferable from the viewpoint of mechanical strength of the resin. In the present disclosure, the melt flow rate is a value measured at 200 ° C. and a load of 49 N in accordance with ISO 1133.

  Although there is no restriction | limiting in particular about the polymerization method of the copolymer resin (a) based on this invention, The block polymerization method or the solution polymerization method can be employ | adopted preferably as a radical polymerization method. The polymerization method mainly comprises a polymerization step for polymerizing a polymerization raw material (monomer component) and a devolatilization step for removing volatile components such as unreacted monomer and polymerization solvent from the polymerization product. Hereinafter, the polymerization method of the copolymer resin (a) according to the present invention will be described.

  When the polymerization raw material is polymerized in order to obtain the copolymer resin (a) according to the present invention, the polymerization raw material composition typically contains a polymerization initiator and a chain transfer agent. As the polymerization initiator, organic peroxides such as 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t- Peroxyketals such as butylperoxy) valerate, dialkyl peroxides such as di-t-butyl peroxide, t-butylcumyl peroxide and dicumyl peroxide, diacyl peroxides such as acetyl peroxide and isobutyryl peroxide, diisopropyl peroxydicarbonate Peroxydicarbonates such as t-butylperoxyacetate, ketone peroxides such as acetylacetone peroxide, and hydroperoxides such as t-butylhydroperoxide. Of these, 1,1-bis (t-butylperoxy) cyclohexane is preferable from the viewpoint of the decomposition rate and the polymerization rate.

  Examples of the chain transfer agent include α-methylstyrene linear dimer, n-dodecyl mercaptan, t-dodecyl mercaptan, n-octyl mercaptan, and the like.

  As the polymerization method, solution polymerization using a polymerization solvent can be employed as necessary. Examples of the polymerization solvent used include aromatic hydrocarbons such as ethylbenzene and dialkyl ketones such as methyl ethyl ketone, which may be used alone or in combination of two or more. Other polymerization solvents such as aliphatic hydrocarbons can be further mixed with the aromatic hydrocarbons as long as the solubility of the polymerization product is not lowered. These polymerization solvents are preferably used in an amount not exceeding 25 parts by mass with respect to 100 parts by mass of all monomers. When the polymerization solvent exceeds 25 parts by mass with respect to 100 parts by mass of all monomers, the polymerization rate is remarkably reduced, and the mechanical strength of the resulting resin tends to be greatly reduced. Prior to the polymerization, the addition of 5 to 20 parts by mass with respect to 100 parts by mass of all monomers is easy to make the quality uniform and is preferable from the viewpoint of controlling the polymerization temperature.

  The apparatus used in the polymerization step for obtaining the copolymer resin (a) according to the present invention is not particularly limited, and may be appropriately selected according to the polymerization method of the styrene resin. For example, in the case of bulk polymerization, a polymerization apparatus in which one or a plurality of complete mixing reactors are connected can be used. There is no particular limitation on the devolatilization step, and when performing bulk polymerization, the polymerization proceeds until the final unreacted monomer is preferably 50% by mass or less, more preferably 40% by mass or less. In order to remove volatile components such as volatile components, devolatilization is performed by a known method. For example, a normal devolatilization apparatus such as a flash drum, a biaxial devolatilizer, a thin film evaporator, and an extruder can be used. In addition, the temperature of the devolatilization treatment is usually about 190 to 280 ° C, and from the viewpoint of suppressing the formation of a six-membered cyclic acid anhydride due to the adjacent methacrylic acid and methyl methacrylate, 190 to 260 ° C is more preferable. . Moreover, the pressure of a devolatilization process is about 0.13-4.0 kPa normally, Preferably it is 0.13-3.0 kPa, More preferably, it is 0.13-2.0 kPa. As the devolatilization method, for example, a method of removing volatile matter by reducing the pressure under heating and a method of removing the volatile matter through an extruder designed for the purpose of removing the volatile matter are desirable.

<MBS resin (b)>
In the resin composition of the present invention, an MBS resin (b) obtained by grafting a copolymer mainly composed of a methyl methacrylate monomer unit and a styrene monomer unit onto rubber-like particles comprising a butadiene monomer unit. ) Content is preferably 1 to 15% by mass, more preferably 2 to 100% by mass of the total mass of the copolymer resin (a), MBS resin (b) and copolymer resin (c). ˜13 mass%, more preferably 3˜11 mass%. Here, the copolymer component grafted onto the rubber-like particles composed of butadiene monomer units is mainly composed of a methyl methacrylate monomer unit and a styrene monomer unit. It means that the ratio of the total monomer units of methyl methacrylate and styrene to the monomer units is 92% by mass or more, and this ratio is preferably 94% by mass or more, more preferably 96% by mass or more. is there. Examples of monomer units other than methyl methacrylate and styrene include butyl acrylate monomer. When the butyl acrylate monomer is contained, the fluidity is preferably improved, but if the content is too large, the heat resistance tends to decrease. When MBS resin (b) is used, a resin composition excellent in improvement in mechanical strength can be obtained. However, when the amount used is less than 1 mass, there is a tendency for improvement in mechanical strength to be low, whereas when it exceeds 15 mass%. The butadiene monomer unit content in the resin composition increases, foaming becomes difficult due to outgassing at the time of foam molding, and the physical properties of the resulting foam tend to be reduced. Moreover, there exists a tendency for the rigidity of the obtained molded article to fall and the external appearances, such as a sheet | seat, to fall.

  The content of butadiene monomer units forming the rubber-like particles in the MBS resin (b) is preferably 50% by mass or more, more preferably 60% by mass, and even more preferably 65% by mass or more. The higher the butadiene monomer unit content, the smaller the added amount, the greater the improvement in mechanical strength, and the less the decrease in heat resistance. On the other hand, if the butadiene monomer unit content is too high, the content of the graft copolymer consisting of the methyl methacrylate monomer unit and the styrene monomer unit is reduced, and the compatibility with the copolymer resin (a) is reduced. The sheet appearance tends to be lowered. The butadiene monomer unit content is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less.

  In the MBS resin (b), the mass composition ratio of the methyl methacrylate monomer unit to the styrene monomer unit is preferably in the range of 30/70 to 70/30, more preferably in the range of 35/65 to 65/35. is there. When the composition ratio is in the range of 30/70 to 70/30, compatibility with the copolymer resin (a) is improved, which is advantageous from the viewpoint of mechanical strength and sheet appearance.

<Copolymer resin (c)>
In the resin composition of the present invention, the content of the copolymer resin (c) composed of a maleated styrene-ethylene-butylene-styrene block copolymer is the copolymer resin (a), the MBS resin (b), and the copolymer resin. It is preferable that it is 1-15 mass% with respect to 100 mass% of total mass of (c), More preferably, it is 2-13 mass%, More preferably, it is 3-11 mass%. By using the copolymer resin (c), a resin composition excellent in improvement in mechanical strength can be obtained. However, if the amount used is less than 1 mass, the improvement in mechanical strength tends to be low, whereas it exceeds 15 mass%. In such a case, foaming becomes difficult due to degassing during foam molding, and the physical properties of the resulting foam tend to be reduced. Moreover, there exists a tendency for the rigidity of the obtained molded article to fall and the external appearances, such as a sheet | seat, to fall.

  The styrene monomer unit content in the copolymer resin (c) is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, and still more preferably 15 to 35% by mass. The styrene monomer unit content is preferably 10% by mass or more from the viewpoint of compatibility with the copolymer resin (a), and preferably 50% by mass or less from the viewpoint of improvement in mechanical strength.

  When the resin composition of the present invention contains both the MBS resin (b) and the copolymer resin (c), the total content of each is the copolymer resin (a), the MBS resin (b) and the copolymer. Although what is necessary is just 1-15 mass% with respect to 100 mass% of total mass of resin (c), the example of preferable content is 2-13 mass in total of MBS resin (b) and copolymer resin (c). %, And a more preferable example is 3 to 11% by mass.

<Rubber-modified styrene resin (d)>
The rubber-modified styrenic resin (d) in the present invention is produced by dispersing rubbery polymer particles in a styrenic resin matrix and polymerizing a styrene monomer in the presence of the rubbery polymer. can do. In the resin composition of the present invention, the rubber-modified styrene resin (d) can be used by blending with the copolymer resin (a).

  Styrene monomers constituting the styrene resin include α-methylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene in addition to styrene. , Ethyl styrene, isobutyl styrene, and t-butyl styrene or styrene derivatives such as bromostyrene, chlorostyrene, and indene. Styrene is particularly preferable from an industrial viewpoint. These styrene monomers can be used singly or in combination. The styrenic resin does not exclude further inclusion of monomer units other than the above-mentioned styrenic monomer units within a range not impairing the effects of the present invention, but typically comprises a styrenic monomer unit.

  As the rubbery polymer, polybutadiene, polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, and the like can be used. From an industrial viewpoint, polybutadiene and styrene-butadiene copolymer are used. Coalescence is preferred. As the polybutadiene, both high cis polybutadiene having a high cis content and low cis polybutadiene having a low cis content can be used. Moreover, as a structure of a styrene-butadiene copolymer, both a random structure and a block structure can be used. These rubber-like polymers can be used alone or in combination of two or more. A saturated rubber obtained by hydrogenating a butadiene rubber can also be used.

  The content of the rubber-modified polystyrene resin (d) is preferably 30% by mass or less, more preferably 27% by mass or less, and still more preferably 25% by mass or less with respect to the total mass of the resin composition. When the resin composition contains the rubber-modified polystyrene resin (d), the mechanical strength of the resin composition can be improved, but when the content is 30% by mass or less, the butadiene unit amount of the resin composition The body unit content does not increase excessively, it is possible to prevent the foaming from becoming difficult due to outgassing during foam molding, and the physical properties of the resulting foam can be prevented from being lowered. On the other hand, the content is preferably 3% by mass or more, more preferably 5% by mass or more from the viewpoint of obtaining a satisfactory mechanical strength improvement effect.

  The rubber content in the rubber-modified polystyrene resin (d) is preferably 7 to 15% by mass, more preferably 9 to 14% by mass. When the rubber content is 7% by mass or more, the mechanical strength can be prevented from decreasing in the blend with the copolymer resin (a), and the mechanical ratio can be increased by increasing the blend ratio of the rubber-modified polystyrene resin (d). While strength is improved, heat resistance is not greatly reduced, which is preferable. On the other hand, when the rubber content is 15% by mass or less, the viscosity of the polymerization system does not become too high when the rubber-modified polystyrene resin (d) is produced, and it is possible to prevent the operation from becoming difficult, and the rubber particle diameter is easy. Can be miniaturized. Further, when the copolymer resin (a) and the rubber-modified polystyrene resin (d) are blended, it is possible to prevent a decrease in mechanical strength or a defective appearance of the product due to a poor dispersion of the rubber component. The rubber content is measured by the procedures described in the Examples section or by methods understood by those skilled in the art to be equivalent.

  The rubber component in the rubber-modified polystyrene resin (d) can exist as rubber particles in the resin composition. The rubber particle diameter in this case is preferably 0.5 to 5.0 μm, more preferably 0.7 to 4.0 μm, and still more preferably 1.0 to 3.0 μm. When the rubber particle diameter is 0.5 μm or more, the mechanical strength of the resin composition is good. Moreover, when the rubber particle diameter is 5.0 μm or less, the appearance of the resin composition is good. The rubber-modified polystyrene resin (d) is obtained by polymerizing a styrene monomer in a reactor equipped with a stirrer in the presence of a rubbery polymer, and the rubber particle diameter is determined by the number of revolutions of the stirrer. It can be adjusted by the molecular weight of the rubbery polymer. In the present disclosure, the rubber particle diameter is a value measured from a cross-sectional observation image by a transmission electron microscope.

  The melt flow rate at 200 ° C. of the rubber-modified polystyrene resin (d) is preferably 0.5 to 20.0, more preferably 1.0 to 18.0, still more preferably 1.0 to 16.0. Can be. When the melt flow rate is in the range of 0.5 to 20.0, the miscibility with the copolymer resin (a) and MBS (b) is good, and the mechanical strength is also good. In the present disclosure, the melt flow rate is a value measured at 200 ° C. and a load of 49 N in accordance with ISO 1133.

  The production method of the rubber-modified styrenic resin (d) is not particularly limited, but bulk polymerization (or solution polymerization) in which a styrene monomer (and solvent) is polymerized in the presence of a rubbery polymer, or It can be produced by bulk-suspension polymerization that shifts to suspension polymerization during the reaction, or emulsion graft polymerization in which a styrene monomer is polymerized in the presence of a rubber-like polymer latex. In bulk polymerization, a rubber-like polymer, a styrenic monomer, and a mixed solution to which an organic solvent, an organic peroxide, and / or a chain transfer agent are added, if necessary, are used as a complete mixing reactor or tank type. It can be produced by continuously supplying a reactor and a plurality of tank reactors connected in series to a polymerization apparatus constituted.

  In the present invention, the swelling index of the toluene-insoluble part of the rubber-modified styrene resin (d) is 8.0 to 14.0, and the mass ratio of the toluene-insoluble part to the rubber content in the toluene-insoluble part (toluene-insoluble part) / Rubber content in toluene-insoluble matter) is preferably 1.5 to 4.0. The swelling index is more preferably 9.0 to 13.0, still more preferably 9.5 to 12.5, and the ratio of the rubber content in the toluene insoluble content / toluene insoluble content is more preferably 2.0. -3.5, more preferably 2.5-3.5. The swelling index of the toluene insoluble part of the rubber-modified styrene resin (d) is 8.0 to 14.0, and the ratio of the rubber content in the toluene insoluble part / toluene insoluble part is 1.5 to 4.0. In some cases, a resin having excellent mechanical strength can be obtained. In the present disclosure, those skilled in the art will understand that the swelling index of toluene-insoluble matter and the ratio of toluene-insoluble matter / rubber content in toluene-insoluble matter are the same as or equivalent to those described in the Examples section. It is a value measured by such a procedure.

<Copolymer resin (e)>
The resin composition of the present invention contains a copolymer resin (e) having a weight average molecular weight of 1,000,000 or more, which is a copolymer of a methyl methacrylate monomer unit and a butyl acrylate monomer unit. it can. When the resin composition of the present invention contains a copolymer resin (e), the melt tension of the resin composition is improved, stretching is performed, and the mechanical strength is improved, which is preferable. The content of the copolymer resin (e) is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, and still more preferably 2.0% by mass or less, based on the total mass of the resin composition. . When the content is 3.0% by mass or less, the melt tension is not improved excessively, and the moldability at the time of secondary molding is hardly lowered. Further, from the viewpoint of obtaining a good mechanical strength improvement effect, the content is preferably 0.3% by mass or more, and more preferably 0.5% by mass or more. The copolymer resin (e) does not exclude further inclusion of monomer units other than the methyl methacrylate monomer unit and the butyl acrylate monomer unit as long as the effects of the present invention are not impaired. Consists of a methyl methacrylate monomer unit and a butyl acrylate monomer unit.

  The weight average molecular weight of the copolymer resin (e) is preferably 1,000,000 or more, more preferably 2,000,000 or more, and further preferably 3,000,000 or more. On the other hand, from the viewpoint of fluidity, the weight average molecular weight of the copolymer resin (e) is preferably 6,000,000 or less, more preferably 5,500,000 or less, and further preferably 5,000,000 or less. . The composition ratio of methyl methacrylate and butyl acrylate is preferably in the range of 90/10 to 65/35, more preferably 85/15 to 70/30, from the viewpoint of fluidity.

  The resin composition of the present invention has a Vicat softening temperature of 106 ° C. or higher, preferably 108 ° C. or higher, more preferably 110 ° C. or higher. If the Vicat softening temperature is 106 ° C. or higher, the deformation of the sheet or container is small and good even when immersed in boiling water or heated in a microwave oven. Moreover, the Vicat softening temperature of the resin composition of the present invention is preferably 130 ° C. or lower, and more preferably 125 ° C. or lower. Vicat softening temperature of 106 ° C or higher adjusts Vicat softening temperature of copolymer resin (a) to be used, Vicat softening temperature of MBS resin (b) and / or copolymer resin (c) to be used, and mixing ratio of these resins This can be achieved.

  As a mixing method of the copolymer resin (a), the MBS resin (b) and / or the copolymer resin (c), and any rubber-modified styrenic resin (d) and / or any copolymer resin (e) Although not particularly limited, after mixing and pelletizing with an extruder or the like, the obtained pellets are used to produce a sheet or foam by sheet extrusion or foam extrusion, or directly into a sheet extruder or foam extruder. Copolymer resin (a), MBS resin (b) and / or copolymer resin (c), and any rubber-modified styrenic resin (d) and / or any copolymer resin (e) in a predetermined ratio Examples thereof include a method for directly producing a sheet or a foam.

  When the total mass of the resin composition of the present invention is 100% by mass, the total amount of styrene dimer and styrene trimer is preferably 0.6% by mass or less, more preferably 0.5% by mass. It is as follows. If the total remaining amount of styrene dimer and styrene trimer is 0.6% by mass or less, for example, in injection molding, the adhesion of styrene dimer and styrene trimer to the mold is greatly increased. The transfer of these styrene dimers and styrene trimers to molded products is greatly reduced, the appearance defects are greatly improved, and in the extrusion molding of sheets and the like, the styrene dimer that precipitates on the die is reduced. Productivity is greatly reduced as the amount of mer and styrene trimer is greatly reduced, transfer to the sheet is greatly reduced, appearance defects are greatly improved, and the need to clean the mold and die outlets can be reduced. Will also improve. The residual amount of styrene dimer and styrene trimer can be measured by gas chromatography.

  When the total mass of the resin composition of the present invention is 100% by mass, the residual amount of styrene monomer is preferably 700 ppm or less, more preferably 600 ppm or less, still more preferably 500 ppm or less. If the residual amount of styrene monomer is 700 ppm or less, the odor around the die outlet during sheet extrusion is improved, and the color tone of the resin is also improved. The residual amount of styrene monomer can be measured by gas chromatography.

<Aliphatic primary alcohol>
In the resin composition of the present invention, an aliphatic primary alcohol having a freezing point of −10 ° C. or less and a carbon number of 14 or more is used as a component other than the aliphatic primary alcohol in the heat-resistant styrene resin composition. You may add 0.02-1.0 mass part with respect to a total of 100 mass parts. The blending of the aliphatic primary alcohol is effective for suppressing the gelation reaction due to the dehydration reaction of methacrylic acid as described in Patent Document 1 or 2 described above, and particularly when the copolymer resin (a) is produced. It is desirable to add an aliphatic primary alcohol into the system. Alcohols having less than 14 carbon atoms tend to volatilize when a high vacuum is applied for the purpose of removing low-volatile components such as residual monomers or moisture during the production of the copolymer resin (a) and during sheet extrusion. There exists a tendency for the inhibitory effect of a chemical reaction to fade. Therefore, it is preferable that the aliphatic primary alcohol has a larger carbon number.

  The addition amount of the aliphatic primary alcohol having 14 or more carbon atoms relative to 100 parts by mass is preferably 0.02 to 1.0 part by mass. The addition amount of the aliphatic primary alcohol is more preferably 0.04 to 0.8 parts by mass, and still more preferably 0.06 to 0.6 parts by mass. Under the alcohol addition conditions such that the addition amount is 0.02 parts by mass or more, the effect of suppressing the gelation reaction is good during the devolatilization step during the production of the copolymer resin (a) or during the extrusion of the sheet. On the other hand, under the addition conditions such that the addition amount is 1.0 part by mass or less, while the gelling reaction suppressing effect is favorably obtained, the residual amount of the aliphatic primary alcohol in the resin composition is increased. However, it is preferable because there is little significant decrease in the heat resistance of the resin, and mold deposits are unlikely to occur during molding. Among aliphatic primary alcohols having 14 or more carbon atoms, iso-type aliphatic primary alcohols having a freezing point of −10 ° C. or lower are particularly preferable. When the freezing point is −10 ° C. or lower, when high vacuum is applied for the purpose of removing low volatile components such as moisture and residual monomers, the alcohol is preferably not precipitated in a condenser or the like, and the degree of vacuum is not easily lowered. The content of the aliphatic primary alcohol having 14 or more carbon atoms can be measured by gas chromatography.

  Examples of the aliphatic primary alcohol having 14 or more carbon atoms include n-myristic acid alcohol, n-palmitic acid alcohol, and n-stearyl alcohol. Further, as isoaliphatic primary alcohols having a freezing point of -10 ° C or lower, isotetradecanol having 14 carbon atoms, isohexadecanol having 16 carbon atoms, isooctadecanol having 18 carbon atoms, isocarbon having 20 carbon atoms, Eicosanol, for example, specifically, 7-methyl-2- (3-methylbutyl) -1-octanol, 5-methyl-2- (1-methylbutyl) -1-octanol, 5-methyl- 2- (3-methylbutyl) -1-octanol, 2-hexyl-1-decanol, 5,7,7-trimethyl-2- (1,3,3-trimethylbutyl) -1-octanol, 8-methyl-2 -(4-methylhexyl) -1-decanol, 2-heptyl-1-undecanol, 2-heptyl-4-methyl-1-decanol, 2- (1,5-dimethylhexyl) - (5,9-dimethyl) -1-decanol, and the like. Among these, isooctadecanol having 18 carbon atoms is particularly preferable from an industrial viewpoint.

  The resin composition of the present invention may further contain a stabilizer. Examples of general stabilizers include hindered phenols such as octadecyl-3- (3,5-t-butyl-4-hydroxyphenyl) propionate and 4,6-bis (octylthiomethyl) -o-cresol. Examples thereof include antioxidants and phosphorus processing heat stabilizers such as tris (2,4-di-t-butylphenyl) phosphite. These stabilizers can be appropriately used alone or in combination of two or more. There is no restriction | limiting in particular about addition time, For example, it can add at the polymerization process or devolatilization process of resin, or can be added at the time of extrusion of a resin with a sheet extruder or a foaming extruder. The content of the stabilizer is, for example, preferably 0.01 to 0.6% by mass, more preferably 0.05 to 0.4% by mass with respect to the total mass of the resin composition.

  The resin composition of the present invention may comprise 85 to 99% by mass of the above-described copolymer resin (a) and 1 to 15% by mass of the above-described MBS resin (b) and / or copolymer resin (c). In addition to the copolymer resin (a), MBS resin (b) and / or copolymer resin (c), the rubber-modified styrene resin (d), copolymer resin (e), and aliphatic first It may contain one or more selected from secondary alcohols, and may contain additional resins such as general polystyrene, random copolymer elastomers of styrene-butadiene, polyphenylene ether, and the like. In addition, for example, the resin composition of the present invention may be prepared by adding commonly used additives, for example, lubricants, antioxidants, ultraviolet absorbers, mold release agents, liquid paraffin and other plasticizers, dyes, A pigment, various fillers, etc. can be contained. Resin compositions containing such additives can be used for various moldings. The additive may be added in advance during the production of the copolymer resin (a), the MBS resin (b) and / or the copolymer resin (c). The total content of the copolymer resin (a), the MBS resin (b) and the copolymer resin (c) with respect to the total mass of the resin composition is preferably 96 from the viewpoint of obtaining the above-described effects satisfactorily. It is at least 97% by mass, more preferably at least 97% by mass, even more preferably at least 98% by mass. On the other hand, for example, from the viewpoint of obtaining a desired effect by other components as exemplified above, the copolymer resin (a), the MBS resin (b), and the copolymer resin (c) with respect to the total mass of the resin composition. The total content is preferably 99.8% by mass or less, more preferably 99.5% by mass or less, and still more preferably 99.0% by mass or less.

[Extruded sheet]
The present invention also provides an extruded sheet formed using the above-described resin composition of the present invention. The extruded sheet may be non-foamed or foamed. As a method for producing an extruded sheet, a generally known method can be used. Examples of the method for producing a non-foamed extruded sheet include a method using a short-axis or biaxial extruder with a T-die and a device that pulls a sheet with a uniaxial stretching machine or a biaxial stretching machine. Examples of the sheet manufacturing method include a method using an extrusion foam molding machine equipped with a T die or a circular die.

  In the case of forming a foamed extruded sheet, commonly used substances can be used as the foaming agent and foaming nucleating agent during extrusion foaming. As the foaming agent, butane, pentane, chlorofluorocarbon, carbon dioxide, water or the like can be used, butane is preferred. Moreover, talc etc. can be used as a foam nucleating agent.

In the foamed extruded sheet, the thickness is preferably 0.5 mm to 5.0 mm, the apparent density is preferably 50 g / L to 300 g / L, and the basis weight is 80 g / m ^{2 to} 300 g / m ^2. It is preferable that In addition, the foamed extruded sheet may be used in the form of a multilayer with styrene resin such as polystyrene resin, for example, high impact polystyrene (impact resistant polystyrene) made of a rubber component such as styrene-butadiene block copolymer or polybutadiene. Further, it may be used in a multilayer with a resin other than the styrenic resin. Examples of the resin other than the styrene resin include polypropylene (PP) resin, PP / polystyrene (PS) resin, polyethylene terephthalate (PET) resin, and nylon resin.

  On the other hand, in the non-foamed extruded sheet, for example, the thickness is preferably about 0.1 to 1.5 mm from the viewpoint of rigidity and thermoforming cycle. The non-foamed extruded sheet may be formed only by ordinary low-magnification roll stretching. In particular, the sheet is stretched by 1.3 to 7 times with a roll and then stretched by 1.3 to 7 times with a tenter. Is preferable in terms of strength. Further, the non-foamed extruded sheet may be used in a multilayer form with a styrene resin such as a polystyrene resin, for example, a high impact polystyrene made of a rubber component such as a styrene-butadiene block copolymer or polybutadiene. You may use it multilayered with resin other than resin. Examples of resins other than styrene resins include PP resins, PP / PS resins, PET resins, and nylon resins.

[Molding]
The present invention also provides a molded article formed using the above-described non-foamed extruded sheet or foamed extruded sheet of the present invention. A foamed extruded sheet or a multilayer body including the same can be formed by, for example, vacuum forming to produce a container such as a tray. In addition, the non-foamed extruded sheet can be formed, for example, by vacuum forming to prepare a container for storing a lunch box lid or side dish.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited only to these Examples. The resins and extruded sheets in Examples and Comparative Examples were evaluated by the following analysis or measurement method.

[Properties of copolymer resin (a), rubber-modified styrene resin (d), and resin composition]
(1) Measurement of content (mass%) of each monomer unit of styrene, methacrylic acid and methyl methacrylate of copolymer resin (a):
The resin composition was quantified from the integral ratio of the spectrum measured with a proton nuclear magnetic resonance (1H-NMR) measuring instrument.
Sample preparation: 30 mg of resin pellets were dissolved in 0.75 ml of d6-DMSO by heating at 60 ° C. for 4 to 6 hours.
Measuring instrument: JNM ECA-500 manufactured by JEOL Ltd.
Measurement conditions: measurement temperature 25 ° C., observation nucleus 1H, integration count 64 times, repetition time 11 seconds.
(Spectral attribution)
Spectral assignments measured in dimethyl sulfoxide deuterated solvent are 0.5 to 1.5 ppm peak, methacrylic acid, methyl methacrylate and hydrogen of α-methyl group of 6-membered cyclic acid anhydride, 1.6 to 2 The .1 ppm peak is the hydrogen of the methylene group of the polymer main chain, the 3.5 ppm peak is the hydrogen of methyl methacrylate carboxylate (-COOCH ₃ ), and the 12.4 ppm peak is the hydrogen of carboxylic acid of methacrylic acid. . Moreover, the peak of 6.5-7.5 ppm is hydrogen of the aromatic ring of styrene. In addition, since the resin of the present invention has a low content of six-membered cyclic acid anhydrides, it is usually difficult to quantify with this measurement method.

(2) Measurement of Vicat softening temperature (° C):
Measured according to ISO 306. The load was 49N.

(3) Measurement of weight average molecular weight (10,000):
Sample preparation: About 0.05% by mass of a resin was dissolved in tetrahydrofuran.
(Measurement condition)
Instrument: TOSOH HLC-8220GPC (gel permeation chromatography)
Column: super HZM-H
Temperature: 40 ° C
Carrier: THF 0.35 ml / min
Detector: RI, UV: 254 nm
Calibration curve: Use of standard PS made by TOSOH

(4) Measurement of melt flow rate:
Measurement was performed in accordance with ISO 1133 (200 ° C., load 49 N).

(5) Measurement of rubber particle diameter:
The rubber particle diameter was measured by taking a transmission electron micrograph by an ultrathin section method, measuring the particle diameter of 1000 particles in the photograph, and obtaining the rubber particle diameter by the following equation.
Rubber particle size = Σni × Di ⁴ / Σni × Di ³
(Where ni is the number of rubber particles having a particle diameter Di, and Di is determined by the average value of the major axis and minor axis of the particle)

(6) Measurement of swelling index of toluene insoluble matter:
Precisely weigh 1 g of rubber-modified styrenic resin in the sedimentation tube (this mass is W1), add 20 ml of toluene, shake at 23 ° C. for 2 hours, and centrifuge (HIMAC, CR-manufactured by Hitachi, Ltd.). 20 (rotor: R20A2)) at 10 ° C. or less and 20000 rpm for 60 minutes. The sedimentation tube was slowly tilted to about 45 degrees, and the supernatant was removed by decantation. Accurately weigh the mass of insoluble matter (this is in a state accompanied with toluene) (this mass is set to W2), then vacuum-dry at 160 ° C. under 3 kPa for 1 hour, and cool to room temperature in a desiccator Thereafter, the mass of toluene-insoluble matter was precisely weighed (this mass is designated as W3).
The swelling index of toluene-insoluble matter was determined by the following formula.
Swelling index of toluene insoluble matter = (W2 / W3)

(7) Toluene-insoluble content / Measurement of rubber content ratio in toluene-insoluble content 0.25 g of rubber-modified styrene resin was dissolved in 50 ml of chloroform, and iodine monochloride was added to react the double bond in the rubber component. Thereafter, potassium iodide was added, the remaining iodine monochloride was changed to iodine, and back titration was performed with sodium thiosulfate (iodine monochloride method). By this method, the rubber content (W4: mass%) in the rubber-modified styrene resin was measured, and from this value, the rubber content in the rubber-modified styrene resin (W1) in (6) above, that is, the toluene insoluble content. The rubber content (W5) in was determined by the following formula:
Rubber content in toluene insoluble matter (W5) = W1 × W4 / 100
The mass ratio of the toluene insoluble component to the rubber content in the toluene insoluble component (toluene insoluble component / rubber content in the toluene insoluble component) was determined by the following equation.
Toluene insoluble matter / rubber content in toluene insoluble matter = W3 / W5

(8) Measurement of residual amount (% by mass) of styrene dimer and styrene trimer when the resin composition is 100% by mass:
Sample preparation: After 2.0 g of the resin composition was dissolved in 20 ml of methyl ethyl ketone, 5 ml of methanol containing a standard substance was further added and dissolved.
(Measurement condition)
Apparatus: Gas chromatography GC-17Apf manufactured by Shimadzu Corporation
Column: DB-1 (100% dimethylpolysiloxane) 30 m,
Film thickness 0.1μm, 0.25mmφ
Column temperature: held at 100 ° C. for 2 minutes → heated to 260 ° C. at 5 ° C./minute→held at 260 ° C. for 5 minutes Inlet temperature: 200 ° C.
Detector temperature: 200 ° C
Carrier gas: Nitrogen

(9) Measurement of content (ppm) of styrene monomer when the resin composition is 100% by mass:
Sample preparation: 1.0 g of the resin composition was dissolved in 25 ml of dimethylformamide containing a standard substance.
(Measurement condition)
Equipment: Gas chromatography GC-14Bpf manufactured by Shimadzu Corporation
Column: SUS 3mmφ × 3m (packed column)
Filler: Liquid phase → PEG-20M 25%
Carrier → Chromosorb W (AW) 60-80 mesh Column temperature: 110 ° C.
Inlet temperature: 220 ° C
Detector temperature: 220 ° C
Carrier gas: Nitrogen

(10) Measurement of aliphatic primary alcohol content (% by mass) in resin composition:
Sample preparation: 0.5 g of the resin composition was dissolved in 20 ml of methyl ethyl ketone.
(Measurement condition)
Equipment: Gas chromatography GC2010 manufactured by Shimadzu Corporation
Column: DB-WAX 30 m, 0.25 mmφ, df = 0.5 μm
Temperature: 100 ° C. → 5 ° C./min to 130 ° C. → 10 ° C./min to 180 ° C. → 180 ° C. for 12 minutes → 20 ° C./min to 220 ° C. → 220 ° C. for 20 minutes Retention

[Injection molding characteristics and injection molded product characteristics]
(11) Measurement of Charpy impact strength (kJ / m ² ):
Measurement was performed without a notch in accordance with ISO 179.
(12) Bending strength (MPa):
Measured according to ISO 178.
(13) Bending deflection (mm):
When measuring the bending strength in (12) above, the maximum amount of deflection was measured.

(14) Judgment of mold contamination Using a 150 x 150 x 2.5 mm strip mold, a short shot was made at the time of injection molding in a filling time of 5.0 seconds. After completion of 70 shots, the injection molding is stopped for 15 minutes, the mold is cooled, the mold surface corresponding to the tip of the molded body is visually observed, and the mold is molded up to 700 shots while confirming the dirt on the mold. Repeated. Mold contamination was determined according to the following evaluation criteria.
(Double-circle): There is no mold dirt in 700 shots.
○: Dust contamination occurred in 420 to 630 shots.
Molding was performed at a mold temperature of 20 ° C. and a resin temperature of 260 ° C. In addition, when the components of the mold dirt deposits were measured by gas chromatography according to the procedure described above, most of the styrene dimer and styrene trimer contained a slight amount of alcohol kneaded in the resin. It was.

[Non-foaming extrusion characteristics and non-foaming extrudate characteristics]
(15) Measurement of non-foamed sheet impact strength (kg · cm):
The impact strength was measured with a film impact tester (A121807502) manufactured by Toyo Seiki Co., Ltd. for a 0.1 mm thick stretched sheet produced under predetermined conditions.

(16) Heat resistance of non-foamed extruded sheet:
For a 0.1 mm-thick stretched sheet produced under predetermined conditions, the shrinkage ratio of 5-fold stretching in the sheet extrusion direction when immersed in a silicone oil bath at 105 ° C. for 30 minutes is determined according to the following evaluation criteria. did. A shrinkage rate of less than 3% is practically preferable.
A: Shrinkage rate of less than 3% B: Shrinkage rate of 3% or more and less than 6% X: Shrinkage rate of 6% or more

(17) Appearance determination of non-foamed extruded sheet:
Three sheets having a size of 8 cm × 20 cm are cut out from a 0.1 mm-thick stretched sheet prepared under predetermined conditions, and foreign matter having an average diameter of (major axis + minor axis) / 2 of 1 mm or more is formed on the surface of the three sheets. The number of certain gels was counted, and the appearance was judged according to the following evaluation criteria.
◎: Number of gels is 2 or less ○: Number of gels is 3 to 5 ×: Number of gels is 6 or more

(18) Odor determination at die outlet At the time of sheet extrusion, the odor at the die outlet was confirmed, and the odor at the die outlet was determined according to the following evaluation criteria.
◎: Almost no odor ○: Slight odor

[Foamed extrudate characteristics]
(19) Measurement of impact strength (kg · cm) of foam sheet:
About the foam sheet produced on predetermined conditions, impact strength was measured with the film impact tester (A121807502) by Toyo Seiki Co., Ltd.

[Production of copolymer resin (a)]
[Resin B]
From 71.0 parts by mass of styrene, 7.5 parts by mass of methacrylic acid, 6.5 parts by mass of methyl methacrylate, 15.0 parts by mass of ethylbenzene, 0.025 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane The polymerization raw material composition liquid was fed at a rate of 1.1 liter / hour to a fully mixed reactor having a capacity of 4 liters, then to a polymerization apparatus comprising a 2 liter laminar flow reactor, and then to unreacted monomers Then, the resin was prepared by continuously supplying to a devolatilizer connected with a single screw extruder for removing volatile components such as a polymerization solvent. The polymerization reaction conditions in the polymerization step were a polymerization temperature of 125 ° C. for a complete mixing reactor and a polymerization temperature of 120 to 142 ° C. for a laminar flow reactor. The devolatilized unreacted gas was condensed by a condenser through which a refrigerant at −5 ° C. was passed and recovered as an unreacted liquid. The polymer content in the final polymerization solution was measured by the formula [(sample weight after drying / sample weight before drying) × 100%] after drying the polymer solution at 215 ° C. under a reduced pressure of 2.5 kPa for 30 minutes. The weight average molecular weight was 211,000 (211,000). Table 1 shows the composition ratio, characteristics, and the like of the obtained resin.

[Resin A, Resins C to D]
The composition, polymerization temperature conditions, and the like were adjusted so that the resin properties shown in Table 1 were obtained, and a copolymer resin (a) was obtained in the same manner as for the resin B.

[MBS resin (b)]
Mitsubishi Rayon Co., Ltd. is an MBS resin (b) obtained by grafting a methyl methacrylate monomer unit, a styrene monomer unit and a small amount of a copolymer of butyl acrylate onto rubber-like particles composed of butadiene monomer units. Metabrene C-223A (butadiene monomer unit content: 70% by mass, total content of methyl methacrylate monomer unit and styrene monomer unit: 29% by mass, methyl methacrylate monomer / styrene unit (Mer composition ratio = 1/1, butyl acrylate monomer unit: 1%).

[Copolymer resin (c)]
As copolymer resin (c) which is a maleated styrene-ethylene-butylene-styrene block copolymer, Tuftec M1913 (styrene monomer unit content 30 mass%) manufactured by Asahi Kasei Chemicals Corporation was used.

[Production of rubber-modified styrene resin (d)]
[Resin E]
A rubber-modified styrenic resin was produced using a polymerization apparatus in which three laminar flow reactors (1.5 liters) equipped with a stirrer were connected in series, and then an extruder equipped with a two-stage vent was arranged. In a raw material tank with a stirrer, 82 parts by mass of styrene, 12 parts by mass of ethylbenzene, 6.7 parts by mass of diene 55 manufactured by Asahi Kasei Chemicals as a rubber component, 0.02 parts by mass of 1,1-bis (t-butylperoxy) cyclohexane After dissolving the rubber component with a stirrer, this raw material solution is supplied to the reactor at a capacity of 0.75 liter / hr, the temperature of the first stage reactor is 110 to 120 ° C., and the second stage reaction is performed. Polymerization was carried out at a temperature of 120 to 130 ° C. and a temperature of the third stage reactor of 140 to 150 ° C. The extruder temperature was 210 to 240 ° C., the degree of vacuum was 3 kPa, and the total solid content in the polymerization solution discharged from the final reactor was 77.9% by mass. The rubber particle size was controlled by adjusting the rotation speed of the stirrer of the first stage laminar flow reactor to 115 rpm. Table 3 shows the composition and characteristics of the obtained resin.

[Resins F to H]
Conditions were adjusted so that the properties of the resin shown in Table 2 were obtained, and a rubber-modified styrene resin (d) was obtained in the same manner as for the resin E. In addition, in order to obtain the rubber particle diameters shown in Table 2, the rotational speeds of the stirrers of the first stage laminar flow reactor were adjusted to 250 rpm and 30 rpm, respectively, for the resin G and the resin H.

[Copolymer resin (e)]
As copolymer resin (e) which is a copolymer of methyl methacrylate monomer units and butyl acrylate monomer units, METABRENE P-531A (weight average molecular weight: 4,500,000) manufactured by Mitsubishi Rayon Co., Ltd. Was used.

[Example 1]
As shown in Table 3 below, MBS (b) was mixed at a ratio of 7% by mass with respect to 93% by mass of the resin A as the copolymer resin (a), and an isoaliphatic primary alcohol was further added. Then, it extruded with the twin-screw extruder and produced the resin pellet. The alcohol content (% by mass) in the resin composition shown in Table 3 below is a value determined by gas chromatography. The MBS resin (b) in Table 3 below is a product (Metbrene C-223A) manufactured by Mitsubishi Rayon Co., Ltd., and an isoaliphatic primary alcohol is a product manufactured by Nissan Chemical Co. (Fine Oxocol 180, Freezing point: −30 ° C. or lower) was used.

  Using the obtained resin pellets, non-foamed extrudates (non-foamed extrudate sheets) and foamed extrudates (foamed extrudate sheets and tray containers as molded products) were produced and evaluated for physical properties and the like. For the non-foamed extruded sheet, a 25 mmφ single-screw sheet extruder manufactured by Souken Co., Ltd. was used to prepare a sheet having a resin melting zone temperature of 220 to 230 ° C. and a thickness of about 0.7 mm. After heating at 140 ° C. for 10 minutes with a biaxial stretching apparatus EX6-S1 manufactured by the company, the sheet was stretched 5 times in the sheet extrusion direction and 1.5 times in the direction perpendicular to the sheet extrusion to produce a sheet of about 0.1 mm. . The foamed extruded sheet was impregnated with a liquefied carbon dioxide gas at 10 mPa for 30 minutes in an autoclave on a sheet of about 0.18 mm thickness produced by compression molding, and then heated to 117 ° C., and the heating time was adjusted appropriately to expand about 10 times. A body sheet was prepared. The properties and evaluation results of the obtained non-foamed extrudate and foamed extrudate are shown in Table 3 below.

[Examples 2 to 10]
Copolymer resin (a), MBS (b) and / or copolymer resin (c), and rubber-modified styrenic resin (d) and copolymer resin (e) as necessary are mixed in the proportions shown in Table 3 below. Furthermore, after adding an isoaliphatic primary alcohol, the resin pellets were produced by extrusion with a twin-screw extruder, and, as in Example 1, non-foamed extrudates and foamed extrudates were produced. Physical properties were evaluated. The evaluation results are shown in Table 3 below. The sheet stretching temperature and the foaming temperature of the liquefied carbon dioxide-containing sheet were increased or decreased by the difference in Vicat softening temperature from Example 1.

[Comparative Example 1]
A non-foamed extrudate and a foamed extrudate were prepared in the same manner as in Example 1 except that 100% by mass of the resin A was used as the copolymer resin (a) and no MBS (b) was added. Table 3 below shows the evaluation results of properties and physical properties of the obtained product. In Comparative Example 1, by adding no MBS resin (b), mechanical strength such as Charpy impact strength, impact strength of non-foamed sheet and foamed sheet was inferior to that of Example 1. .

[Comparative Example 2]
The same non-foamed extrudate and foamed extrudate were carried out in the same manner as in Example 1 except that 93% by mass of the resin D as the copolymer resin (a) and 7% by mass of the MBS resin (b) were mixed. Was prepared. Table 3 below shows the evaluation results of properties and physical properties of the obtained product. In Comparative Example 2, the copolymer resin (a) was changed from the resin B to the resin D, and a resin having a high methacrylic acid content was used. Compared to Example 1, the appearance of the non-foamed sheet was inferior.

[Comparative Example 3]
Except for mixing 83% by mass of resin A as copolymer resin (a) and 17% by mass of MBS resin (b), the same procedure as in Example 1 was carried out. Was prepared. Table 3 below shows the evaluation results of properties and physical properties of the obtained product. In Comparative Example 3, the amount of MBS resin (b) added was increased from 7% by mass to 17% by mass. Compared to Example 1, the Vicat softening temperature decreased from 108 ° C. to 102 ° C., and the heat resistance and further the appearance of the non-foamed sheet were inferior.

[Comparative Example 4]
The same as in Example 6 except that 84% by mass of the resin B as the copolymer resin (a) and 16% by mass of the copolymer resin (c) were mixed. A product was prepared. Table 3 below shows the evaluation results of properties and physical properties of the obtained product. In Comparative Example 4, the amount of MBS resin (b) added was increased from 6% by mass to 16% by mass. Compared to Example 6, the appearance of the non-foamed sheet and the impact strength of the foamed sheet were inferior.

  Using the heat-resistant styrene-based resin composition of the present invention, non-foamed and foamed extruded plates, extruded sheets, and food products by secondary processing thereof, molded articles such as packaging materials, heat resistance, mechanical strength, Excellent appearance and moldability. Furthermore, the heat-resistant styrene-based resin composition of the present invention can be widely used as a raw material for molded products by injection molding and the like for electrical product parts, toys, miscellaneous goods, daily necessities, and various industrial parts. It plays a big role.

Claims (12)

A copolymer resin (a) which is a styrene-methacrylic acid-methyl methacrylate copolymer, and a rubber-like particle comprising a butadiene monomer unit containing a methyl methacrylate monomer unit and a styrene monomer unit as main components. A heat-resistant styrene resin containing one or both of an MBS resin (b) obtained by grafting the copolymer and a copolymer resin (c) which is a maleated styrene-ethylene-butylene-styrene block copolymer A composition comprising:
Content of the said copolymer resin (a) is 85-99 mass% with respect to 100 mass% of total mass of the said copolymer resin (a), the said MBS resin (b), and the said copolymer resin (c). And the total content of the MBS resin (b) and the copolymer resin (c) is 1 to 15% by mass,
When the copolymer resin (a) has a total content of styrene monomer units, methacrylic acid monomer units, and methyl methacrylate monomer units of 100% by mass, the styrene monomer unit is 69%. -96 mass%, and 4-16 mass% of methacrylic acid monomer units, and 0-15 mass% of methyl methacrylate monomer units,
The heat-resistant styrene resin composition, wherein the Vicat softening temperature of the heat-resistant styrene resin composition is 106 ° C or higher.   The total residual amount of styrene dimer and styrene trimer is 0.6% by mass or less and the residual amount of styrene monomer is 700 ppm or less with respect to the total mass of the heat-resistant styrene resin composition. The heat-resistant styrene resin composition according to claim 1.   The heat-resistant styrene resin composition according to claim 1 or 2, wherein the copolymer resin (a) has a weight average molecular weight of 100,000 to 350,000.   The butadiene monomer unit content in the MBS resin (b) is 50% by mass or more, and the mass composition ratio of methyl methacrylate and styrene in the MBS resin (b) is 30/70 to 70/30. The heat-resistant styrenic resin composition according to any one of claims 1 to 3.   The heat-resistant styrene-type resin composition of any one of Claims 1-4 whose styrene monomer unit content in the said copolymer resin (c) is 10-50 mass%. The rubber-modified styrene resin (d) is further contained in an amount of 30% by mass or less with respect to 100% by mass of the total mass of the heat-resistant styrene resin composition,
The rubber content in the rubber-modified styrenic resin (d) is 7 to 15% by mass,
The heat-resistant styrene resin composition according to any one of claims 1 to 5, wherein the rubber-modified styrene resin (d) has a rubber particle diameter of 0.5 to 5.0 µm.   The swelling index of the toluene-insoluble matter of the rubber-modified styrene resin (d) is 8.0 to 14.0, and the mass ratio of the toluene-insoluble matter to the rubber content in the toluene-insoluble matter (toluene-insoluble matter / The heat-resistant styrene-based resin composition according to claim 6, wherein the rubber content in the toluene insoluble matter is 1.5 to 4.0.   A copolymer resin (e) having a weight average molecular weight of 1,000,000 or more, which is a copolymer of a methyl methacrylate monomer unit and a butyl acrylate monomer unit, is obtained from the heat-resistant styrenic resin composition. The heat-resistant styrenic resin composition according to any one of claims 1 to 7, further containing 3.0% by mass or less based on 100% by mass of the total mass.   The aliphatic primary alcohol having a freezing point of −10 ° C. or lower and a carbon number of 14 or higher is added to a total of 100 parts by mass of the components other than the aliphatic primary alcohol in the heat-resistant styrene resin composition. The heat-resistant styrene-based resin composition according to any one of claims 1 to 8, further contained in an amount of 0.02 to 1.0 part by mass.   The non-foaming extrusion sheet formed using the heat-resistant styrene-type resin composition of any one of Claims 1-9.   The foam extrusion sheet | seat formed using the heat-resistant styrene-type resin composition of any one of Claims 1-9.   A molded article formed using the non-foamed extruded sheet according to claim 10 or the foamed extruded sheet according to claim 11.