JP2014051620A - Thermoplastic resin composition, manufacturing method of the same and molded article - Google Patents

Abstract

A thermoplastic resin composition having excellent heat distortion resistance and impact strength and also excellent recyclability is obtained.
SOLUTION: 80 to 99.0 (% by mass) of methacrylic acid ester monomer units and 1.0 to 20 (other vinyl monomer units copolymerizable with at least one methacrylic acid ester monomer). The weight average molecular weight measured by gel permeation chromatography (GPC) is 40000-250,000, and the molecular weight component of 1/5 or less of the peak molecular weight (Mp) obtained from the GPC elution curve is 7%. Methacrylic resin (A) contained in -40%: 20-80% by mass,
Aliphatic polyester-based resin (B): 80 to 20% by mass;
A thermoplastic resin composition.
[Selection] Figure 2

Description

  The present invention relates to a thermoplastic resin composition, a method for producing the same, and a molded article.

  In recent years, various aliphatic polyesters having biodegradability have attracted attention due to increasing environmental problems. Among them, polylactic acid has established mass production technology from plant-derived raw materials such as corn and sweet potato, and is expected to increase in the future.

Polylactic acid has the advantage of having a higher melting point (Tm) than other aliphatic polyesters, but on the other hand, it has a low glass transition temperature (Tg), and therefore has heat resistance in a temperature range above Tg. It tends to run short. Further, as a disadvantage of polylactic acid, it is regarded as a problem that hydrolysis tends to occur during heating and melting, leading to yellowing and deterioration of physical properties.
In order to improve the heat resistance of the polylactic acid, there is a method of blending a resin having a higher Tg and compatibility than that of polylactic acid. However, a composition in which polylactic acid is mixed with other biodegradable resins is required. In recent years, many studies have been made on mixing a general-purpose non-biodegradable resin with polylactic acid.
For example, from the viewpoint of compatibility, there is a technique of blending a transparent resin having a high Tg such as an acrylic resin as a general-purpose non-degradable resin.

On the other hand, polylactic acid and acrylic resin have different plasticization melting temperatures, and generally acrylic resins have higher plasticization melting temperatures. For example, when resin blending is performed with an extruder or the like, The heat history more than necessary is added, the hydrolysis is promoted, and there is a problem that yellowing and deterioration of physical properties may be caused.
Furthermore, manufacturing of recycled products is also attracting attention from the viewpoint of increasing demand for ecology and recyclability in recent years, but yellowing coloring of recycled products by applying an excessive heat history to polylactic acid. Have the problem of inviting.

In view of the above-mentioned problems, various acrylic resins have been studied for the purpose of improving compatibility with aliphatic polyesters such as polylactic acid and improving heat resistance.
For example, Patent Document 1 proposes a technique for improving the heat resistance and durability by improving the compatibility by using an acrylic resin having a weight average molecular weight (Mw) in a specific range.
Patent Document 2 proposes a technique for improving compatibility with the aliphatic polyester, heat resistance, and transparency by using an acrylic resin with controlled tacticity.

JP-A-2005-171204 JP 2006-328368 A

However, although the resin composition using the acrylic resin described in Patent Document 1 has improved compatibility and improved heat resistance, the set temperature at the time of extrusion melting is still high. Since the heat history is applied, there is a problem that yellowing coloring may occur.
Further, in the sheet obtained from the resin composition using the acrylic resin described in Patent Document 2, although the heat resistance is improved, there is a possibility that the characteristic deterioration due to the thermal decomposition of polylactic acid may occur. Has the problem.

  Therefore, in the present invention, a thermoplastic resin containing an aliphatic polyester resin that is excellent in heat distortion resistance, has a practically sufficient impact strength, suppresses deterioration of characteristics due to heat, and is excellent in recyclability. It aims at providing a composition and its molded object.

As a result of intensive studies to solve the above problems, the present inventors have found that a thermoplastic resin composition containing a specific methacrylic resin and an aliphatic polyester resin has excellent heat distortion resistance and recyclability. The present invention was also completed.
That is, the present invention is as follows.

[1]
Methacrylic acid ester monomer units 80 to 99.0 (mass%) and other vinyl monomer units 1.0 to 20 (mass%) copolymerizable with at least one methacrylic acid ester monomer; The weight average molecular weight measured by gel permeation chromatography (GPC) is 40000-250,000, and 7-40% of molecular weight components equal to or less than 1/5 of the peak molecular weight (Mp) obtained from the GPC elution curve are included. Methacrylic resin (A): 20-80% by mass,
Aliphatic polyester-based resin (B): 80 to 20% by mass;
A thermoplastic resin composition.
[2]
The thermoplastic resin composition according to [1], wherein the aliphatic polyester-based resin (B) is polylactic acid.
[3]
The methacrylic resin (A) has a weight average molecular weight of 40,000 to 150,000 measured by gel permeation chromatography (GPC), and a molecular weight component of 1/5 or less of the peak molecular weight (Mp) obtained from the GPC elution curve. The thermoplastic resin composition according to [1] or [2], which is a methacrylic resin contained in an amount of 7% to 20%.
[4]
A method for producing the thermoplastic resin composition according to any one of [1] to [3],
A monomer unit of 0 to 20 (mass%) composed of at least one methacrylate monomer unit of 80 to 100 (mass%) and another vinyl monomer copolymerizable with the methacrylate monomer. ), And a step of producing a polymer (I) having a weight average weight of 5000 to 50000 measured by gel permeation chromatography with respect to the entire methacrylic resin (A), 5 to 40 (mass%); ,
A raw material mixture containing a methacrylic acid ester is added in the presence of the polymer (I), and another vinyl monomer copolymerizable with the methacrylic acid ester monomer unit 80 to 99.5 (mass%) and the methacrylic acid ester. Polymer (II) containing 0.5 to 20 (% by mass) of monomer units composed of at least one monomer and having a weight average molecular weight of 60,000 to 300,000 is added to the entire methacrylic resin (A). On the other hand, a step of producing 95-60 (mass%);
A step of producing a methacrylic resin (A) by:
Kneading the methacrylic resin (A) and the aliphatic ester resin (B);
A process for producing a thermoplastic resin composition.
[5]
A molded article obtained by molding the thermoplastic resin composition according to any one of [1] to [3].
[6]
A beverage cup obtained by molding the thermoplastic resin composition according to any one of [1] to [3].

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin composition and molded article which are excellent in heat-resistant deformation property, have practically sufficient impact strength, and are excellent also in recyclability are obtained.

The explanatory view about the accumulation area area on the GPC (gel permeation chromatography) elution curve measurement graph of methacrylic resin is shown. It is a figure which shows the accumulation area area in the predetermined elution time on a GPC elution curve measurement graph.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified within the scope of the gist.
In the present specification, the monomer component before polymerization is referred to as “˜monomer”, and “monomer” may be omitted.
In addition, the structural unit constituting the polymer is referred to as “˜monomer unit”, and may be simply referred to as “˜unit”.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment is
Methacrylic acid ester monomer units 80 to 99.0 (mass%) and other vinyl monomer units 1.0 to 20 (mass%) copolymerizable with at least one methacrylic acid ester monomer; The weight average molecular weight measured by gel permeation chromatography (GPC) is 40000-250,000, and 7-40% of molecular weight components equal to or less than 1/5 of the peak molecular weight (Mp) obtained from the GPC elution curve are included. Methacrylic resin (A): 20-80% by mass,
Aliphatic polyester-based resin (B): 80 to 20% by mass;
Containing.

(Methacrylic resin (A))
The methacrylic resin (A) has a methacrylic acid ester monomer unit of 80 to 99.0% by mass and another vinyl monomer unit 1.0 to copolymerizable with at least one methacrylic acid ester monomer. And 20% by mass.
The methacrylic resin (A) has a weight average molecular weight of 40000 to 250,000 as measured by gel permeation chromatography (GPC), and a molecular weight component of 1/5 or less of the peak molecular weight (Mp) obtained from the GPC elution curve. Is contained in an amount of 7 to 40%.

<Methacrylate monomer unit>
The monomer constituting the methacrylic acid ester monomer unit constituting the methacrylic resin (A) is not particularly limited as long as the effects of the invention can be achieved. Preferred examples include the following general formula (1) ).

In the general formula (1), R ₁ represents a methyl group.
R ₂ represents a group having 1 to 12 carbon atoms, and may have a hydroxyl group on the carbon.
The monomer constituting the methacrylic acid ester monomer unit is not limited to the following, for example, butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, isopropyl methacrylate, methacrylic acid Examples include cyclohexyl, phenyl methacrylate, methacrylic acid (2-ethylhexyl), methacrylic acid (t-butylcyclohexyl), benzyl methacrylate, methacrylic acid (2,2,2-trifluoroethyl). It is methyl methacrylate.
The said methacrylic acid ester monomer can also be used 1 type or in combination of 2 or more types.
Moreover, the said methacrylic acid ester monomer may use the same thing in the polymer (I) and polymer (II) mentioned later, and may use a different thing.

Content of the methacrylic acid ester monomer unit which constitutes methacrylic resin (A) is 80-99.0 (mass%) in methacrylic resin (A).
When the content of the methacrylic acid ester monomer unit is 80% by mass or more, a heat resistance effect is obtained in the methacrylic resin composition of the present embodiment, and when it is 99.0% by mass or less, fluidity is obtained. The effect is obtained. Preferably, it is 88-99.0 mass%, More preferably, it is 90-99.0 mass%.

<Other vinyl monomer units copolymerizable with methacrylate monomers>
Examples of the monomer that constitutes the other vinyl monomer unit that can be copolymerized with the above-described methacrylic acid ester monomer constituting the methacrylic resin (A) are represented by the following general formula (2). Acrylic acid ester monomer.

In the general formula (2), R ₃ is a hydrogen atom, and R ₄ is an alkyl group having 1 to 18 carbon atoms.

  Examples of the acrylate monomer represented by the general formula (2) include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate. , Sec-butyl acrylate, 2-ethylhexyl acrylate, and the like, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferable, and methyl acrylate is more easily available and more preferable.

  Examples of vinyl monomers that are copolymerizable with the methacrylic acid ester monomer other than the acrylic acid ester monomer of the general formula (2) include the following examples. Although not limited, for example, α, β-unsaturated acids such as acrylic acid and methacrylic acid, unsaturated group-containing divalent carboxylic acids such as maleic acid, fumaric acid, itaconic acid, cinnamic acid, and the like Alkyl ester; styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p- Styrenic monomers such as ethyl styrene, m-ethyl styrene, о-ethyl styrene, p-tert-butyl styrene, isopropenyl benzene (α-methyl styrene); -Vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, etc. Aromatic vinyl compounds; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenyl N-substituted maleimides such as maleimide and N-cyclohexylmaleimide; amides such as acrylamide and methacrylamide; ethylene glycol di (meth) acrylate and diethyleneglycol Monopentyl ester of ethylene glycol or oligomers thereof such as di (meth) acrylate, triethylene glycol di (meth) acrylate, or tetraethylene glycol di (meth) acrylate; Monomers obtained by esterifying hydroxyl groups of two alcohols such as glycol di (meth) acrylate and di (meth) acrylate with acrylic acid or methacrylic acid; polyhydric alcohol derivatives such as trimethylolpropane and pentaerythritol with acrylic acid or Monomers esterified with methacrylic acid; polyfunctional monomers such as divinylbenzene.

  In the methacrylic resin (A), for the purpose of improving properties such as heat resistance and processability, a vinyl monomer other than the vinyl monomers exemplified above may be added as appropriate and copolymerized. .

As for the acrylic acid ester monomer copolymerizable with the above methacrylic acid ester monomer and vinyl monomers other than the above exemplified acrylic acid ester monomer, only one kind may be used alone. You may use combining a seed | species or more.
Moreover, the said vinyl-type monomer may use the same thing in the polymer (I) and polymer (II) mentioned later, and may use different things.

Content of the other vinyl monomer unit which can copolymerize the methacrylic acid ester monomer which comprises methacrylic resin (A) is 1.0-20 mass% in methacrylic resin (A). It is.
In order to improve fluidity and heat resistance, it is necessary to be 1.0% by mass or more. Moreover, in order to improve heat resistance, it is necessary to be 20 mass% or less.
Preferably it is 1.0-15 mass%, More preferably, it is 1.0-12 mass%, More preferably, it is 1.0-10 mass%.

<Molecular weight and molecular weight distribution of methacrylic resin (A)>
The molecular weight and molecular weight distribution of the methacrylic resin (A) constituting the thermoplastic resin composition of the present embodiment will be described.
The methacrylic resin (A) has a weight average molecular weight (Mw) measured by GPC (gel permeation chromatography) of 40000 to 250,000.
By setting the weight average molecular weight of the methacrylic resin (A) to 40000 or more, excellent mechanical strength can be obtained in a molded product including the thermoplastic resin composition of the present embodiment.
Moreover, the fluidity | liquidity excellent in the methacrylic resin (A) and the thermoplastic resin composition of this embodiment is obtained by making the weight average molecular weight (Mw) of a methacrylic resin (A) into 250,000 or less.
When the weight average molecular weight of the methacrylic resin (A) is within the above range, excellent molding process fluidity can be obtained.
Considering the balance between fluidity and mechanical strength, the weight average molecular weight (Mw) of the methacrylic resin (A) is preferably 40000 to 230,000, more preferably 40000 to 200000, further preferably 40000 to 170000, and further 40000 to 150,000. More preferred.
The weight average molecular weight (Mw) of the methacrylic resin (A) can be measured by the method described in Examples described later.

The molecular weight distribution (weight average molecular weight / number average molecular weight: Mw / Mn) of the methacrylic resin (A) constituting the thermoplastic resin composition of the present embodiment is further increased in order to promote plasticization under a low temperature region. In order to maintain the molding fluidity and mechanical strength in the thermoplastic resin composition containing the component (B) described later, 2.0 ≦ Mw / Mn ≦ 5.0 is preferable, and 2.2 ≦ Mw / Mn ≦ 4.0 is more preferable, and 2.4 ≦ Mw / Mn ≦ 3.5 is more preferable.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC).
Specifically, using a standard methacrylic resin with a known monodispersed weight average molecular weight and available as a reagent, and an analytical gel column that elutes high molecular weight components first, create a calibration curve from the elution time and weight average molecular weight. Keep it. Subsequently, the molecular weight of each sample can be obtained based on the obtained calibration curve, and can be measured by the method described in the examples described later.
The number average molecular weight is a simple average molecular weight per molecule, and is defined by the total weight of the system / number of molecules in the system.
The weight average molecular weight is defined as the average molecular weight by weight fraction.

The methacrylic resin (A) constituting the thermoplastic resin composition of the present embodiment has a peak from the viewpoint of promoting plasticization under a low temperature region and improving the balance of fluidity, heat resistance, and mechanical strength. The amount of the component having a molecular weight of 1/5 or less of the molecular weight (Mp) is 7 to 40%, preferably 7 to 35%, more preferably 7 to 30%, and further preferably 7 to 20%.
In addition, the said peak molecular weight (Mp) refers to the molecular weight which shows a peak in a GPC elution curve.
When there are a plurality of peaks in the GPC elution curve, the peak is indicated by the molecular weight having the highest abundance.

When the amount of the component having a molecular weight of 1/5 or less of the peak molecular weight (Mp) present in the methacrylic resin (A) is 7% or more, fluidity and a good plasticizing effect can be obtained. That is, a plasticizing effect can be added while effectively preventing molding defects such as bleeding out. Moreover, when the abundance of the component is 40% or less, the fluidity, heat resistance, and mechanical strength are well balanced.
Further, the methacrylic resin component having a weight average molecular weight of 500 or less is preferably as small as possible in order to prevent occurrence of a foam-like appearance defect called silver during molding.

  In addition, the other vinyl monomer copolymerizable to the methacrylic acid ester monomer contained in the methacrylic resin (A) included in the thermoplastic resin composition of the present embodiment is a methacrylic resin. The composition ratio in the high molecular weight component (A) is preferably larger than the composition ratio in the low molecular weight component from the viewpoint of stability during polymerization.

<Abundance of components having molecular weight of 1/5 or less of peak molecular weight (Mp)>
The abundance (%) of a component having a molecular weight of 1/5 or less of the peak molecular weight (Mp) of the methacrylic resin (A) contained in the thermoplastic resin composition of the present embodiment described above is the area area in the GPC elution curve. It can be obtained by calculating the ratio (%).
The area area in the GPC elution curve refers to, for example, the shaded portion of the GPC elution curve shown in FIG.
First, the GPC elution curve 6 obtained from the elution time obtained by GPC measurement and the detected intensity by RI (differential refraction detector) intersects the baseline 7 automatically drawn by the measuring instrument and the GPC elution curve 6 Define A and point B.
Point A is a point where the GPC elution curve 6 and the baseline 7 at the beginning of the elution time intersect.
Point B is in principle a position where the molecular weight is 500 or more and the baseline 7 and the GPC elution curve 6 intersect.
When the molecular weight does not intersect within the range of 500 or more, the value of the RI detection intensity at the elution time when the molecular weight is 500 is defined as point B.
A hatched portion surrounded by the GPC elution curve 6 between the points A and B and the line segment AB is an area in the GPC elution curve 6.
This area is the area in the GPC elution curve 6.
By using the column eluted from the high molecular weight component, the high molecular weight component is observed at the beginning of the elution time, the low molecular weight component is observed at the end of the elution time, and the molecular weight can be known from the elution time.
The accumulated area area (%) of the area area in the GPC elution curve 6 corresponds to each elution time toward the end of the elution time, with the point A shown in FIG. 2 being 0% which is the standard of the accumulated area area (%). It is assumed that the detection intensity is accumulated and an area area in the GPC elution curve 6 is formed.
A specific example of the accumulated area area is shown in FIG.
In FIG. 2, a point on the baseline at a certain elution time is a point X, and a point on the GPC elution curve is a point Y. The ratio of the area surrounded by the curve AY, the line segment AB, and the line segment XY to the area area in the GPC elution curve 6 is the value of the accumulated area area (%) at a certain elution time X.
By this method, the abundance (%) of a component having a molecular weight of 1/5 or less of the peak molecular weight (Mp) present in the methacrylic resin (A) can be obtained.

<Method for producing methacrylic resin (A)>
Hereinafter, the preferable manufacturing method of methacrylic resin (A) contained in the thermoplastic resin composition of this embodiment is demonstrated.
The methacrylic resin (A) can be produced by a multistage polymerization method.
First, in the first stage polymerization, using a raw material mixture composed of at least one methacrylate monomer and at least one other vinyl monomer copolymerizable with the methacrylate monomer, methacrylic acid is used. Including 80 to 100% by mass of ester monomer units and 0 to 20% by mass of monomer units composed of at least one other vinyl monomer copolymerizable with a methacrylic acid ester monomer, The polymer (I) having a weight average molecular weight of 5,000 to 50,000 measured in (5) is produced in an amount of 5 to 40% by mass based on the entire target methacrylic resin (A).
Next, the inside of the polymerization system is maintained at a temperature higher than the first stage polymerization temperature for a certain period of time.
Thereafter, in the presence of the polymer (I), a raw material mixture composed of at least one of a methacrylic acid ester monomer and another vinyl monomer copolymerizable with the methacrylic acid ester monomer is added. The monomer unit is composed of 80 to 99.5% by mass of a methacrylic acid ester monomer unit and at least one other vinyl monomer copolymerizable with the methacrylic acid ester. The polymer (II) containing ˜20 mass% and having a weight average molecular weight measured by GPC of 60,000 to 300,000 is produced from 95 to 60 mass% based on the entire target methacrylic resin (A).

Presence of polymer (I) (hereinafter simply referred to as polymer (I)) obtained by the first stage polymerization and having a weight average molecular weight of 5,000 to 50,000 as measured by GPC, and the presence of polymer (I) The raw material mixture containing a methacrylic ester is added below, and the content of polymer (II) (henceforth only polymer (II)) obtained by the 2nd-stage polymerization whose weight average molecular weight is 60000-300000 is mentioned. The ratio is the ratio of the polymer (I) as described above from the viewpoint of improving the polymerization stability during production, the fluidity of the methacrylic resin (A), and the mechanical strength of the molded article of the thermoplastic resin composition. Is 5 to 40% by mass, and the ratio of the polymer (II) is 95 to 60% by mass.
Considering the balance of polymerization stability, fluidity and mechanical strength of the molded product, the ratio of polymer (I) / (II) is preferably 10 to 40% by mass / 90 to 60% by mass, more preferably 15 to It is 35 mass% / 85-65 mass%, More preferably, it is 20-35 mass% / 80-65 mass%.

Further, as described above, the polymer (I) is composed of 80 to 100% by mass of methacrylic acid ester monomer units and at least one other vinyl monomer copolymerizable with the methacrylic acid ester. It is a polymer containing 0 to 20% by mass of monomer units.
The ratio of the monomer units constituting the polymer (I) can be adjusted by controlling the amount of monomer added in the polymerization step of the polymer (I) of multistage polymerization.
The polymer (I) preferably has less other vinyl monomers copolymerizable with methacrylic acid esters, and may not be used.
The molecular weight is 5000 to 50000, preferably 10,000 to 45000, preferably 20000 to 40000, in terms of weight average weight measured by GPC, from the viewpoints of suppression of defects such as silver during molding, polymerization stability, and fluidity. More preferred.
As will be described later, the weight average molecular weight of the polymer (I) can be controlled by using a chain transfer agent or an iniferter, adjusting these amounts, or appropriately changing the polymerization conditions.

The polymer (II) is composed of 80 to 99.5% by mass of a methacrylic acid ester monomer unit and at least one other vinyl monomer copolymerizable with the methacrylic acid ester monomer. It is a polymer containing 0.5 to 20% by mass of monomer units.
The ratio of the monomer units constituting the polymer (II) can be adjusted by controlling the amount of monomer added in the polymerization step of the multistage polymer (II).
From the viewpoint of solvent resistance and fluidity, the molecular weight is 60,000 to 300,000, preferably from 130000 to 280000, more preferably from 150,000 to 260000, and even more preferably from 150,000 to 240000, as measured by GPC.
As will be described later, the weight average molecular weight of the polymer (II) can be controlled by using a chain transfer agent or an iniferter, adjusting these amounts, or appropriately changing the polymerization conditions.

The methacrylic resin (A) contained in the thermoplastic resin composition of the present embodiment can be produced by a multistage polymerization method as described above.
That is, as described above, in the first polymerization step, the methacrylic acid ester monomer alone or another vinyl copolymerizable with the methacrylic acid ester monomer and at least one methacrylic acid ester monomer. Polymer (I) is polymerized using the monomer.
In the second polymerization step, in the presence of the polymer (I), a methacrylic acid ester monomer and another vinyl monomer copolymerizable with at least one methacrylic acid ester monomer are added. In this polymerization method, the composition of each of the polymer (I) and the polymer (II) can be easily controlled, and the temperature rise due to the heat of polymerization during the polymerization is suppressed. The viscosity inside can be stabilized.

In this case, the polymerization of the raw material composition of the polymer (II) may be partly initiated before the polymerization of the polymer (I) is completed. It is preferable to add the raw material composition mixture of the polymer (II) after the polymerization is completed by keeping the temperature higher than the polymerization temperature.
By curing in the first stage, not only the polymerization is completed, but also unreacted monomers, initiators, chain transfer agents, etc. can be removed or deactivated, which adversely affects the second stage polymerization. It will not reach. As a result, the target weight average molecular weight can be obtained.

The polymerization temperature may be produced by appropriately selecting an optimum polymerization temperature according to the polymerization method, but is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 60 ° C. or higher and 90 ° C. or lower.
The polymerization temperature of the polymer (I) and the polymer (II) may be the same or different.
The temperature raised during the curing is preferably 5 ° C. or more higher than the polymerization temperature of the polymer (I), more preferably 7 ° C. or more, and further preferably 10 ° C. or more.
Further, the holding time is preferably 10 minutes or more and 180 minutes or less, more preferably 15 minutes or more and 150 minutes or less.

When producing the methacrylic resin (A) contained in the thermoplastic resin composition of the present embodiment, a polymerization initiator may be used.
As a polymerization initiator, when performing radical polymerization, it is not limited to the following. For example, di-t-butyl peroxide, lauroyl peroxide, stearyl peroxide, benzoyl peroxide, t-butyl peroxide Neodecanate, t-butylperoxypivalate, dilauroyl peroxide, dicumyl peroxide, t-butylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) -3, Organic peroxides such as 3,5-trimethylcyclohexane and 1,1-bis (t-butylperoxy) cyclohexane, azobisisobutyronitrile, azobisisovaleronitrile, 1,1-azobis (1-cyclohexane) Carbonitrile), 2,2′-azobis-4-methoxy-2,4-azobis Sobuchironitoriru, 2,2'-azobis-2,4-dimethylvaleronitrile, mention may be made of conventional radical polymerization initiator azo such as 2,2'-azobis-2-methylbutyronitrile.
These may be used alone or in combination of two or more.
A combination of these radical initiators and an appropriate reducing agent may be used as a redox initiator.
These polymerization initiators are generally used in the range of 0 to 1 part by mass with respect to 100 parts by mass of the total amount of all monomers used in the polymerization. It can be appropriately selected in consideration of the half-life.

When a bulk polymerization method, a cast polymerization method, or a suspension polymerization method is selected as a method for performing the above-described multistage polymerization, from the viewpoint of preventing coloring of the methacrylic resin (A), a peroxide polymerization method is performed. Initiators can be suitably used, and include, but are not limited to, lauroyl peroxide, decanoyl peroxide, t-butylperoxy-2-ethylhexanoate, and the like. Peroxide is more preferred.
When polymerizing the methacrylic resin (A), when the solution polymerization method is performed at a high temperature of 90 ° C. or higher, the 10-hour half-life temperature is 80 ° C. or higher and is soluble in the organic solvent to be used. It is preferable to use a peroxide, an azobis initiator, or the like. Examples of the peroxide and azobis initiator include, but are not limited to, for example, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2, Examples include 5-dimethyl-2,5-di (benzoylperoxy) hexane, 1,1-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile and the like.

When producing the methacrylic resin (A) constituting the thermoplastic resin composition of the present embodiment, the molecular weight modifier of the methacrylic resin (A) should be used within a range that does not impair the purpose of the present invention. Can do.
Although not limited to the following, for example, in the polymerization step of the polymers (I) and (II), chain transfer agents such as alkyl mercaptans, dimethylacetamide, dimethylformamide, triethylamine, dithiocarbamates, triphenylmethyl The molecular weight can be controlled by using iniferters such as azobenzene and tetraphenylethane derivatives. Moreover, it is possible to adjust molecular weight by adjusting these addition amounts.
When these are used, from the viewpoint of handleability and stability, alkyl mercaptans that are chain transfer agents are preferably used, and are not limited to the following, but include, for example, n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, 2-ethylhexyl thioglycolate, ethylene glycol dithioglycolate, trimethylolpropane tris (thioglycolate), pentaerythritol tetrakis (thioglycolate) Etc.
These can be appropriately added according to the molecular weight of the target methacrylic resin (A), but generally 0.001 to 3 parts by weight with respect to 100 parts by weight of the total amount of all monomers used. Used in the range of parts by mass.

Other molecular weight adjusting methods include a method of changing the polymerization method, a method of adjusting the amount of the polymerization initiator, and a method of changing the polymerization temperature.
As these molecular weight adjusting methods, only one method may be used, or two or more methods may be used in combination.

(Aliphatic polyester resin (B))
The thermoplastic resin composition of the present embodiment contains an aliphatic polyester resin (B).
The aliphatic polyester-based resin (B) is not limited to the following, but is a polymer comprising an aliphatic hydroxycarboxylic acid as a main constituent, an aliphatic polyvalent carboxylic acid or an ester-forming derivative thereof and an aliphatic. Examples thereof include polymers formed by polycondensation with a polyhydric alcohol as a main component, and copolymers thereof.
Examples of the polymer mainly composed of the aliphatic hydroxycarboxylic acid include polycondensates such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, and hydroxycaproic acid, or copolymers thereof. Etc. In particular, from the viewpoint of biodegradability, polyglycolic acid, polylactic acid, poly-3-hydroxycarboxylic butyric acid, poly-4-polyhydroxybutyric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, and copolymers thereof are preferable. In particular, polylactic acid is more preferable, and poly L-lactic acid, poly D-lactic acid, and stereocomplex polylactic acid and racemic polylactic acid forming a stereocomplex crystal are more preferable.

  When polylactic acid is used as the aliphatic polyester resin (B), the weight average molecular weight is preferably 50,000 or more, more preferably 80,000 or more, further preferably, in order to satisfy practical mechanical properties. 100,000 or more. The weight average molecular weight here refers to the molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography.

What is necessary is just to use what has L-lactic acid and / or D-lactic acid as a main repeating unit as said polylactic acid (here, the main means that this component occupies 50 mol% or more of the whole). To do.)
Further, polylactic acid may contain a copolymerization component other than lactic acid, and the other monomer unit is not particularly limited. For example, ethylene glycol, propylene glycol, butanediol, heptane Diol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, pentaerythritol, bisphenol A, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Glycol compounds, oxalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid Dicarboxylic acids such as bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, glycolic acid, hydroxypropionic acid, hydroxybutyric acid And hydroxy carboxylic acids such as hydroxyvaleric acid, hydroxycaproic acid and hydroxybenzoic acid, and lactones such as caprolactone, valerolactone, propiolactone, undecalactone and 1,5-oxepan-2-one.

  In order to obtain a molded article having high heat resistance using the thermoplastic resin composition of the present embodiment, it is preferable to use a polylactic acid having a high optical purity of the lactic acid component. Specifically, among the total lactic acid components of polylactic acid, it is preferable that the L isomer is contained at 80% or more, or the D isomer is contained at 80% or more, the L isomer is contained at 90% or more, or the D isomer. Is more preferably 90% or more, more preferably 95% or more of L-form, or 95% or more of D-form.

As a method for producing the polylactic acid, a known polymerization method can be used, and examples thereof include a direct polymerization method from lactic acid and a ring-opening polymerization method via lactide.
In addition, after low-molecular-weight polylactic acid containing a metal-containing catalyst is crystallized, it can also be produced by heating, solid-state polymerization under reduced pressure or under pressure, in the presence or absence of an inert gas stream. it can.
Further, it can be produced by a direct polymerization method in which lactic acid is subjected to dehydration condensation in the presence / absence of an organic solvent.

The melting point of the polylactic acid is not particularly limited, but is preferably 120 ° C. or higher, and more preferably 150 ° C. or higher.
The melting point of polylactic acid is usually increased by increasing the optical purity of the lactic acid component, and polylactic acid having a melting point of 120 ° C. or higher should contain 90% or more of L-form or 90% or more of D-form. In addition, polylactic acid having a melting point of 150 ° C. or higher can be obtained by containing 95% or more of L-form or 95% or more of D-form.

The content of the component (B) in 100% by mass of the thermoplastic resin composition of the present embodiment is 20 to 80% by mass, preferably 30 to 70% by mass, and more preferably 40 to 60% by mass.
By setting it as 20 mass% or more, the biodegradable function of the thermoplastic resin composition of this embodiment is obtained, and by setting it as 80 mass% or less, heat-resistant deformation property can be kept favorable.

(Additive)
In order to impart other characteristics such as rigidity and dimensional stability to the thermoplastic resin composition of the present embodiment, various additives such as a phthalate ester and a fatty acid ester are used within a range not impairing the effects of the present invention. Type, trimellitic acid ester type, phosphoric acid ester type, polyester type plasticizer; higher fatty acid, higher fatty acid ester, higher fatty acid mono-, di- or triglyceride type release agent; polyether type, polyether ester -Based, polyether ester amide-based, alkyl sulfonate, alkyl benzene sulfonate, etc .; stabilizers such as antioxidants, UV absorbers, heat stabilizers, light stabilizers; flame retardants, flame retardant aids , Curing agent, curing accelerator, conductivity imparting agent, stress relaxation agent, crystallization accelerator, hydrolysis inhibitor, lubricant, impact imparting agent, slidability improving agent, compatibilizing agent, nucleating agent, strengthening , Reinforcing agent, flow modifier, dye, sensitizer, colorant, rubbery polymer, thickener, anti-settling agent, anti-sagging agent, filler, antifoaming agent, coupling agent, anti-rust agent, antibacterial -Antifungal agents, antifouling agents, conductive polymers, etc. can be added.

<Flame Retardant>
Although it does not specifically limit as a flame retardant, For example, a cyclic | annular nitrogen compound, a phosphorus flame retardant, a silicon | silicone, cage | basket silsesquioxane or its partial cleavage structure, and a silica are mentioned.

<Heat stabilizer>
Although it does not specifically limit as a heat stabilizer, For example, antioxidants, such as a hindered phenolic antioxidant and a phosphorus processing stabilizer, etc. are mentioned, A hindered phenolic antioxidant is preferable.
Specifically, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl) -4-hydroxyphenylpropionamide, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesitylene-2,4,6- Triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, ethylenebis (oxy) Ethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate, hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3 , 5-Tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5- Tris [(4-tert-butyl-3-hydroxy-2,6-xylin) methyl] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di -Tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamine) phenol and the like, and pentaerythritol terakis [3- (3,5-di-ter - butyl-4-hydroxyphenyl) propionate are preferred.

<Ultraviolet absorber>
The ultraviolet absorber is not particularly limited, and examples thereof include benzotriazole compounds, benzotriazine compounds, benzoate compounds, benzophenone compounds, oxybenzophenone compounds, phenol compounds, oxazole compounds, and malons. Examples include acid ester compounds, cyanoacrylate compounds, lactone compounds, salicylic acid ester compounds, and benzoxazinone compounds, with benzotriazole compounds and benzotriazine compounds being preferred.
These may be used alone or in combination of two or more.

In the case of adding an ultraviolet absorber, from the viewpoint of molding processability, the vapor pressure (P) at 20 ° C. is preferably 1.0 × 10 ⁻⁴ Pa or less, more preferably 1.0 × 10 ⁻⁶ Pa. Or less, more preferably 1.0 × 10 ⁻⁸ Pa or less.
“Excellent molding processability” means, for example, that the ultraviolet absorber is less adhered to the roll during sheet molding.
If it adheres to the roll, for example, it may adhere to the surface of the molded body and deteriorate the appearance and optical properties, so it is not preferable when the molded body is used as an optical material.
Moreover, it is preferable that melting | fusing point (Tm) of an ultraviolet absorber is 80 degreeC or more, More preferably, it is 100 degreeC or more, More preferably, it is 130 degreeC or more, More preferably, it is 160 degreeC or more.
The UV absorber preferably has a weight loss rate of 50% or less, more preferably 30% or less, and even more preferably 15% or less when the temperature is increased from 23 ° C. to 260 ° C. at a rate of 20 ° C./min. Even more preferably, it is 10% or less, and still more preferably 5% or less.

<Rubber polymer>
The rubbery polymer is not particularly limited. For example, organic rubber particles having a multilayer structure such as general butadiene-based ABS rubber, acrylic-based, polyolefin-based, silicon-based, and fluororubber are used. Is preferred.
In particular, particles having a multilayer structure of three or more layers are preferable, and acrylic rubber particles having a multilayer structure of three or more layers are more preferable from the viewpoint of compatibility with the methacrylic resin (A) described above.
By using organic rubber particles having a multilayer structure having a three-layer structure or more, the thermoplastic resin composition of the present embodiment suppresses thermal deterioration during molding processing and deformation of the organic rubber particles due to heating. Maintenance of heat resistance and thermal deformation tend to be suppressed.
The organic rubber particles having a multilayer structure of three or more layers are rubber particles having a multilayer structure in which a soft layer made of a rubber-like polymer and a hard layer made of a glass-like polymer are laminated, preferably hard from the inside. It is a particle having a three-layer structure formed in the order of layer-soft layer-hard layer.
By having the hard layer in the innermost layer and the outermost layer, deformation of the organic rubber particles tends to be suppressed, and by having a soft component in the central layer, good toughness tends to be imparted.

For example, when the organic rubber particles are formed of an acrylic rubber having a three-layer structure, the acrylate monomer unit in the copolymer forming the innermost layer (bi) is not particularly limited. For example, n-butyl acrylate and 2-hexyl acrylate are preferable.
When the organic rubber particles contain an aromatic vinyl compound monomer unit as a copolymer component, the aromatic vinyl compound monomer unit is the same as the monomer used for the methacrylic resin (A). Styrene or a derivative thereof is preferably used.
When the copolymer contains a copolymerizable polyfunctional monomer unit, the copolymerizable polyfunctional monomer unit is not particularly limited. For example, ethylene glycol di (meth) acrylate, polyethylene glycol Di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, allyl (meth) acrylate, triallyl isocyanurate, diallyl maleate, divinylbenzene, etc. Can be mentioned. These can be used alone or in combination of two or more.
Of these compounds, allyl (meth) acrylate is particularly preferred.

When the organic rubber particles are formed of an acrylic rubber having a three-layer structure, the copolymer forming the central layer (b-ii) imparts excellent toughness to the methacrylic resin composition of the present embodiment. From the viewpoint, a copolymer showing soft rubber elasticity is preferable.
Although it does not specifically limit as an acrylate ester monomer unit which comprises the copolymer which forms a center layer (b-ii), Preferably, methyl acrylate, ethyl acrylate, acrylate n-butyl, acrylic acid 2-ethylhexyl etc. are mentioned, From these, it can use 1 type or 2 types or more together.
In particular, n-butyl acrylate and 2-hexyl acrylate are preferable.
Moreover, when using an aromatic vinyl compound monomer as a monomer copolymerized with an acrylic ester, styrene or a derivative thereof is preferable as the aromatic vinyl compound monomer.
When the copolymer contains a copolymerizable polyfunctional monomer unit, the copolymerizable polyfunctional monomer unit may be a copolymerizable polyfunctional monomer used in the innermost layer (bi) described above. The same monomer unit can be used, and the content thereof is 0.1% by mass or more and 5% by mass or less, which has a good crosslinking effect and has moderate crosslinking and rubber elasticity. This is preferable because the effect tends to increase.

  When the organic rubber particles are formed of an acrylic rubber having a three-layer structure, the outermost layer (b-iii) of the acrylic organic rubber particles is a single monomer that can be copolymerized with methyl methacrylate. The monomer is preferably not particularly limited, and for example, n-butyl acrylate and 2-hexyl acrylate are preferable.

The method for producing the organic rubber particles is not particularly limited, and can be obtained by a known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, and particularly preferably obtained by emulsion polymerization.
When the organic rubber particles are formed from an acrylic rubber having a three-layer structure, the monomer mixture of the innermost layer (bi) is first added in the presence of an emulsifier and an initiator to complete the polymerization, and then the central layer. By adding the monomer mixture of (b-ii) to complete the polymerization, and then adding the monomer mixture of the outermost layer (b-iii) to complete the polymerization, the multilayer structure particles are easily made into latex. Can be obtained as
The organic rubber particles can be recovered from the latex as a powder by a known method such as salting out, spray drying, freeze drying and the like.

<Filler>
The filler is not particularly limited. For example, glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, flaky glass, talc, kaolin, mica, hydrotalcite , Calcium carbonate, zinc carbonate, zinc oxide, calcium monohydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, silica Magnesium acid, ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, mica, montmorillonite, swellable fluoromica, and apatite And the like.
One type of filler may be used alone, or two or more types may be used in combination.
From the viewpoint of rigidity and strength, glass fiber, carbon fiber, flaky glass, talc, kaolin, mica, calcium carbonate, calcium monohydrogen phosphate, wollastonite, silica, carbon nanotube, graphite, calcium fluoride, montmorillonite, Swellable fluorine mica and apatite are preferred.
Further, these fillers may be appropriately subjected to surface treatment for the purpose of being more familiar with the methacrylic resin (A).

<Colorant>
Examples of the colorant include, but are not limited to, for example, perylene dyes, perinone dyes, pyrazolone dyes, methine dyes, coumarin dyes, quinophthalone dyes, quinoline dyes, anthraquinone dyes, anthraquinone dyes Dyes, asdrapyridone dyes, thioindigo dyes, coumarin dyes, isoindolinone pigments, chicatopyrrolopyrrole pigments, condensed azo pigments, benzimidazolone pigments, dioxazine pigments, copper phthalocyanine pigments, quinacridone Pigments, nickel complex compounds, carbon black, titanium dioxide, alumina oxide, aluminum hydroxide, silicic acid, zinc oxide, zinc stearate, magnesium stearate, calcium stearate, aluminum stearate, barium sulfate, polymethylsilsesquio Sun, halogenated copper phthalocyanine, ethylene bis-stearic acid amide, ultramarine, ultramarine violet, iron oxide, silicon dioxide, mica, talc, liquid paraffin, magnesium silicate, and the like.
Only one colorant may be used alone, or two or more colorants may be used in combination.
Moreover, the various additives mentioned above may be used individually by 1 type, or may be used in combination of 2 or more type.

  As a preferable addition total amount of various additives mentioned above, 0-10 mass parts is preferable with respect to 100 mass parts of thermoplastic resin compositions, 0-8 mass parts is more preferable, and 0-5 mass parts is further more preferable. By controlling the amount to 10 parts by mass or less, each physical property balance such as bleed-out resistance and impact strength can be maintained.

(Other components that can be mixed into the thermoplastic resin composition)
<Other resins>
The thermoplastic resin composition of the present embodiment can be used in combination with conventionally known resins. These can be added as long as the effects of the present invention are not impaired.
The resin to be used is not particularly limited, and known curable resins and thermoplastic resins are preferably used.
Examples of thermoplastic resins include, but are not limited to, polypropylene resins, polyethylene resins, polystyrene resins, syndiotactic polystyrene resins, ABS resins (acrylonitrile-butadiene-styrene copolymers). ), Methacrylic resin, AS resin (acrylonitrile-styrene copolymer), BAAS resin (butadiene-acrylonitrile-acrylonitrile rubber-styrene copolymer, MBS resin (methyl methacrylate-butadiene-styrene copolymer) ), AAS resin (acrylonitrile-acrylonitrile rubber-styrene copolymer), polycarbonate-ABS resin alloy, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytrime Terephthalate, polyalkylene arylate-series resin such as polyethylene naphthalate, polyamide-based resins, polyphenylene ether resins, polyphenylene sulfide resins, phenol resins and the like.
In particular, AS resin and BAAS resin are preferable for improving fluidity, and ABS resin and MBS resin are preferable for improving impact resistance.
In addition, polyphenylene ether resins, polyphenylene sulfide resins, phenol resins, and the like can be expected to have an effect of improving flame retardancy.
Further, the curable resin is not limited to the following, for example, unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, epoxy resin, cyanate resin, xylene resin, triazine resin, urea resin, melamine resin. Benzoguanamine resin, urethane resin, oxetane resin, ketone resin, alkyd resin, furan resin, styrylpyridine resin, silicone resin, synthetic rubber and the like.
These resins may be used alone or in combination of two or more.

As a kneading method in the case of mixing the thermoplastic resin composition with various additives and the above-described other resins, a conventionally known method may be used, and it is not particularly limited.
For example, it can be kneaded and produced using a kneader such as an extruder, a heating roll, a kneader, a roller mixer, a Banbury mixer and the like. Among these, kneading with an extruder is preferable in terms of productivity.

[Method for producing thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment is obtained by kneading the methacrylic resin (A) and the aliphatic polyester resin (B) described above. Furthermore, it is obtained by kneading the various additives and other resins as appropriate.
The methacrylic resin as component (A) can be produced by the method described in the above-mentioned “Method for producing methacrylic resin (A)”.
As a method for kneading the component (A) and the component (B), further various additives as required, and other resins, a conventionally known method may be used, and it is not particularly limited.
For example, it can be kneaded and produced using a kneader such as an extruder, a heating roll, a kneader, a roller mixer, a Banbury mixer and the like.
In particular, kneading with an extruder is preferable in terms of productivity.
In order to suppress thermal decomposition of the aliphatic polyester resin (B), the kneading temperature is further in the range of 140 to 200 ° C. as a guideline from the viewpoint of the recyclability of the thermoplastic resin composition of the present embodiment, preferably Is in the range of 150 to 190 ° C, more preferably in the range of 150 to 180 ° C. By kneading at 200 ° C. or lower, thermal decomposition of the aliphatic polyester resin (B) is significantly suppressed, which leads to improvement in recyclability.

[Molded product of thermoplastic resin composition]
A desired molded product can be obtained by molding the thermoplastic resin composition of the present embodiment.
The thermoplastic resin composition can be molded by a known method of molding in a molten state such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, T-die molding, press molding, and extrusion molding. Secondary processing molding methods such as pressure forming and vacuum forming can also be used.
The thermoplastic resin composition of the present embodiment has good flowability, and as a molding method, injection molding that requires fluidity is particularly preferable, and is effective for high pressure and high speed melt molding. Also, the die swell tends to increase due to the broad molecular weight distribution, which is effective for sheet film formation, and is particularly effective for vacuum forming, pressure forming, punching process, deep drawing process and the like from sheet film formation. .
Another example is a method in which a resin composition is kneaded and manufactured using a kneader such as a heating roll, kneader, Banbury mixer, extruder, etc., then cooled, pulverized, and further molded by transfer molding, injection molding, compression molding, or the like. Can be mentioned. The order of mixing the components is not particularly limited as long as the effect of the present invention can be achieved.
Moreover, the curing method after mixing the thermosetting resin composition and melt-molding differs depending on the curing agent used, but is not particularly limited.
For example, heat curing, light curing, UV curing, curing by pressure, curing by moisture, and the like can be given.

[Use]
The thermoplastic resin composition of the present embodiment can be suitably used for various molded products.
For example, furniture, household goods, storage and stockpiling equipment, toys and playground equipment, medical and welfare equipment, OA equipment, AV equipment, battery electrical equipment, lighting equipment, vehicle parts, especially automobile parts use, housing use, kitchen use, toilet It can be used for water applications such as baths and vanities.
In particular, beverage cups and beverage bottles for dairy products, soft drinks and alcoholic beverages, soy sauce, sauces, mayonnaise, ketchup, containers for seasonings such as edible oil, containers for shampoos and rinses, cosmetic containers, It can be suitably used for resin containers with high recycling frequency such as agricultural chemical containers.
Further, the molded article using the thermoplastic resin composition can be appropriately subjected to surface functionalization treatment such as hard coat treatment, antireflection treatment, transparent conductive treatment, electromagnetic wave shielding treatment, gas barrier treatment and the like.

  Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited thereto.

[Examples and comparative examples relating to thermoplastic resin compositions]
(Raw materials for methacrylic resins)
-Methyl methacrylate (MMA): manufactured by Asahi Kasei Chemicals (2,4-dimethyl-6-tert-butylphenol) manufactured by Chugai Trading Co., Ltd. as a polymerization inhibitor is 2.5 ppm. Added)
-Methyl acrylate (MA): manufactured by Mitsubishi Chemical (added with 14 ppm of 4-methoxyphenol manufactured by Kawaguchi Chemical Industry as a polymerization inhibitor)
N-octylmercaptan: made by Arkema 2-ethylhexyl thioglycolate: made by Arkema lauroyl peroxide: phthium oleum ph Nippon Kagaku Kogyo Co., Ltd., used as a suspending agent ・ Calcium carbonate: Shiraishi Kogyo Co., Ltd., used as a suspending agent, sodium lauryl sulfate: manufactured by Wako Pure Chemical Industries, Ltd. Acrylate (EA): Wako Pure Chemicals, Styrene (ST): Asahi Kasei Chemicals

(Measurement method)
<I. Composition analysis and molecular weight measurement of methacrylic resin>
(1) Composition analysis of methacrylic resin The composition analysis of methacrylic resin was performed by GC (pyrolysis gas chromatography) and mass spectrometry.
Pyrolysis device: PY-2020D made by FRONTIER LAB
Column: DB-1 (length 30 m, inner diameter 0.25 mm, liquid phase thickness 0.25 μm)
Column temperature program: After holding at 40 ° C. for 5 minutes, the temperature was raised to 320 ° C. at a rate of 50 ° C./min, and 320 ° C. was held for 4.4 minutes.
Pyrolysis furnace temperature: 550 ° C
Column inlet temperature: 320 ° C
Gas chromatography: Agilent GC6890
Carrier: pure nitrogen, flow rate 1.0 mL / min
Injection method: Split method (split ratio 1/200)
Detector: JEOL mass spectrometer Automass Sun
Detection method: Electron impact ionization method (ion source temperature: 240 ° C., interface temperature: 320 ° C.)
Sample for measurement: 10 μL of 10 g chloroform solution of 0.1 g methacrylic resin
A sample for measurement was collected in a platinum sample cup for a thermal decomposition apparatus, vacuum-dried at 150 ° C. for 2 hours, and then the sample cup was placed in a thermal decomposition furnace, and the composition of the sample was analyzed under the above conditions.
The composition ratio of the methacrylic resin was determined based on the peak area on the total ion chromatography (TIC) of methyl methacrylate and methyl acrylate and the calibration curve of the following standard sample.
Preparation of standard sample for calibration curve: The ratio of methyl methacrylate and methyl acrylate is (methyl methacrylate / methyl acrylate) = (100 mass% / 0 mass%), (98 mass% / 2 mass%), (94 100% by mass of the solution of methyl methacrylate and methyl acrylate into 50 g of each of 5 types of solutions (mass% / 6 mass%) and (90 mass% / 10 mass%) (80 mass% / 20 mass%). Parts, 0.25 parts by mass of lauroyl peroxide and 0.25 parts by mass of n-octyl mercaptan were added.
Each of these mixed solutions was put into a 100 cc glass ampule bottle, and the air was replaced with nitrogen and sealed.
The glass ampoule bottle was placed in an 80 ° C. water bath for 3 hours and then in an oven at 150 ° C. for 2 hours. After cooling to room temperature, the glass was crushed and the methacrylic resin inside was taken out and subjected to composition analysis. A graph of (methyl acrylate area value) / (methyl methacrylate area value + methyl acrylate area value) and methyl acrylate charge ratio obtained by measurement of a standard sample for a calibration curve is used as a calibration curve. It was.
Thereby, the ratio of methyl methacrylate and other component amounts of the methacrylic resin was analyzed.

(2) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of methacrylic resin (A)
The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the methacrylic resin (A) were measured using the following apparatus and conditions.
Measuring device: Tosoh Corporation gel permeation chromatography (HLC-8320GPC)
Column: One TSK guard column SuperH-H, two TSK gel Super HM-Ms, and one TSK gel Super H 2500 were connected in series in this order.
In this column, the high molecular weight elutes early and the low molecular weight elutes slowly.
Detector: RI (differential refraction) detector (Detection sensitivity: 3.0 mV / min)
Column temperature: 40 ° C
Sample: 0.02 g of a methacrylic resin in 10 mL of tetrahydrofuran Injection amount: 10 μL
Developing solvent: Tetrahydrofuran, flow rate; 0.6 mL / min
As an internal standard, 0.1 g / L of 2,6-di-t-butyl-4-methylphenol (BHT) was added.

The following 10 polymethyl methacrylate calibration kits (PL2020-0101 M-10) having different molecular weights and known monodisperse weight peak molecular weights were used as standard samples for calibration curves.

Peak molecular weight (Mp)
Standard sample 1 1,916,000
Standard sample 2 625,500
Standard sample 3 298,900
Standard sample 4 138,600
Standard sample 5 60,150
Standard sample 6 27,600
Standard sample 7 10,290
Standard sample 85,000
Standard sample 9 2,810
Standard document 10 850

Under the above conditions, the RI detection intensity with respect to the elution time of the methacrylic resin was measured.
Based on the area area in the GPC elution curve and the calibration curve of the seventh-order approximation formula, the weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), GPC peak molecular weight (Mp), and GPC peak of the methacrylic resin (A) The ratio (%) of the component having a molecular weight of 1/5 or less of the molecular weight (Mp) was determined.
When the polymer (I) and the polymer (II) described later are mixed, the GPC elution curve of the polymer (I) alone is measured in advance to obtain the weight average molecular weight, and the polymer (I) Is multiplied by the GPC elution curve of the polymer (I), and the detected intensity at the elution time is multiplied by the polymer (I) and the polymer (II). The GPC elution curve of the polymer (II) alone was obtained by subtracting from the GPC elution curve in which is mixed. From this, the weight average molecular weight (Mw) of the polymer (II) was determined.

<II. Physical property measurement>
(1) Charpy impact strength (no notch)
Using a Charpy impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), molding and measurement were performed in accordance with ISO 179 / 1eU, and used as an index of impact resistance.

(2) Heat-resistant deformation temperature Using an HDT test apparatus (heat distortion tester) (manufactured by Toyo Seiki Seisakusho Co., Ltd.), measurement is performed using a 4 mm-thick test piece in accordance with ISO 306 B50, and the VICAT softening temperature is obtained. It was used as an index for deformability evaluation.

(3) Recyclability Evaluation Each thermoplastic resin was extruded under the conditions shown in Table 4, a 60 mm × 30 mm × 3 mmt plate was molded, and YI measurement was performed.
As an index of yellowing resistance, ΔYI = (YI2 after two-time extrusion) − (YI1 after one-time extrusion) was defined, and the recyclability was evaluated by ○ to × shown below.
For YI measurement, a value in the 60 mm direction of the plate (length through which measurement light passes = 60 mm) was measured using an ASA-I type apparatus manufactured by Nippon Denshoku Industries Co., Ltd.
ΔYI ≦ 5.0; Recyclability ○
5.0 <ΔYI ≦ 10.0; Recyclability △
ΔYI>10.0; recyclability ×

[Production of Methacrylic Resin (Resin 1)]
2 kg of water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were charged into a container having a stirrer to obtain a mixed solution (a).
Next, 27 kg of water was charged into a 60 L reactor, the temperature was raised to 80 ° C., and the raw material of the polymer (I) (raw materials in Table 1 ( I)).
Thereafter, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 70 minutes after adding the raw material of the polymer (I).
Thereafter, the temperature was raised to 92 ° C. at a rate of 1 ° C./min, and then maintained at a temperature of 92 ° C. to 94 ° C. for 30 minutes.
Thereafter, the temperature was lowered to 80 ° C. at a rate of 1 ° C./min, and then the raw material for polymer (II) (raw material (II) in Table 1) was charged into the reactor at the blending amount shown in Table 1 below. Subsequently, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 100 minutes after adding the raw material of the polymer (II).
Thereafter, the temperature was raised to 92 ° C. at a rate of 1 ° C./min and then aged for 60 minutes to substantially complete the polymerization reaction.
Next, in order to cool to 50 ° C. and dissolve the suspending agent, 20 mass% sulfuric acid was added.
Next, the polymerization reaction solution was passed through a 1.68 mm mesh sieve to remove aggregates, and the resulting bead polymer was washed and dehydrated and dried to obtain polymer fine particles.

  Table 2 below shows the monomer charge composition ratio, the weight average molecular weight (Mw), and the ratio of the polymer (I) and the polymer (II) of the polymer (I) and the polymer (II) of the resin 1.

The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 210 ° C., and the strands were cooled and cut to obtain resin pellets (resin 1).
The weight average molecular weight of (resin 1) constituting the obtained resin pellet was 82,000, the peak molecular weight (Mp) was 72,000, and the molecular weight distribution (Mw / Mn) was 2.41. It was.
Moreover, as a result of the compositional analysis by pyrolysis gas chromatography (GC), the composition of the methacrylic resin of (Resin 1) was MMA: 98.5% by mass and MA: 1.5% by mass.
Furthermore, the abundance (%) of the weight average molecular weight component having 1/5 or less of the Mp value was 9.4%.

[Production of methacrylic resins (resins 2 to 13)]
Polymerization was performed using the raw materials shown in Table 1 in the same manner as in the above (Resin 1) to obtain polymer fine particles.
Table 2 shows the monomer charge composition ratio, the weight average molecular weight (Mw) of the polymer (I) and the polymer (II) of (resins 2 to 13), and the ratio of the polymer (I) and the polymer (II). The measurement results of weight average molecular weight (Mw), peak molecular weight (Mp), molecular weight distribution (Mw / Mn) by GPC, abundance (%) of weight average molecular weight component of 1/5 or less of Mp value, and GC Table 3 shows the composition analysis results.

[Production of methacrylic resin (resin 14)]
2 kg of water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were put into a container having a stirrer to obtain a mixed solution (a ′).
Next, 26 kg of water was put into a 60 L reactor and the temperature was raised to 80 ° C., and the mixture (a ′) and methyl methacrylate 21.2 kg, methyl acrylate 0.43 kg, lauroyl peroxide 27 g, n-octyl mercaptan 62 g was charged.
Thereafter, suspension polymerization was carried out while maintaining about 80 ° C., and after observing an exothermic peak, the temperature was raised to 92 ° C. at a rate of 1 ° C./min. Thereafter, the mixture was aged for 60 minutes to substantially complete the polymerization reaction.
Subsequently, 20 mass% sulfuric acid was added in order to cool to 50 ° C. and dissolve the suspending agent.
Next, the polymerization reaction solution was passed through a 1.68 mm mesh sieve to remove aggregates, and the resulting bead polymer was washed and dehydrated and dried to obtain polymer fine particles.
The average particle diameter of the obtained polymer fine particles measured based on JIS-Z8801 was 0.3 μm.
The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 230 ° C., and the strands were cooled and cut to obtain resin pellets (resin 14).
As a result of composition analysis by pyrolysis gas chromatography (GC), the composition of the methacrylic resin of (resin 14) was MMA: 98.0% by mass and MA: 2.0% by mass. Moreover, the weight average molecular weight of the obtained pellet was 106,000, and molecular weight distribution (Mw / Mn) was 1.9. Furthermore, the abundance (%) of the molecular weight component of 1/5 or less of the Mp value was 4.3%.

[Production of methacrylic resin (resin 15)]
2 kg of water, 65 g of tribasic calcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were charged into a container having a stirrer to obtain a mixed solution (b ′).
Next, 26 kg of water was charged into a 60 L reactor and the temperature was raised to 80 ° C., and the mixture (b ′) and methyl methacrylate 21.2 kg, methyl acrylate 1.35 kg, lauroyl peroxide 27 g, n-octyl mercaptan 32.8 g was charged.
Thereafter, suspension polymerization was carried out while maintaining about 80 ° C., and after observing an exothermic peak, the temperature was raised to 92 ° C. at a rate of 1 ° C./min. Thereafter, the mixture was aged for 60 minutes to substantially complete the polymerization reaction.
Subsequently, 20 mass% sulfuric acid was added in order to cool to 50 ° C. and dissolve the suspending agent.
Next, the polymerization reaction solution was passed through a 1.68 mm mesh sieve to remove aggregates, and the resulting bead polymer was washed and dehydrated and dried to obtain polymer fine particles. The average particle diameter of the polymer fine particles measured based on JIS-Z8801 was 0.28 μm.
The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 250 ° C., and the strand was cooled and cut to obtain resin pellets (resin 15).
As a result of the composition analysis by pyrolysis gas chromatography (GC), the composition of the methacrylic resin of (Resin 15) was MMA: 94.0% by mass and MA: 6.0% by mass. Moreover, the weight average molecular weight of the obtained pellet was 176,000, and molecular weight distribution (Mw / Mn) was 1.85. Furthermore, the abundance (%) of a molecular weight component having an Mp value of 1/5 or less was 4.5%.

[Aliphatic ester resin (B)]
(B-1)
Polylactic acid grade name 4042D (manufactured by Cargill Dow)
Weight average molecular weight = 160,000, Tm = 151 ° C., D-form 4.0% by mass
(B-2)
Polylactic acid grade name H-100J (Mitsui Chemicals)
Tm = 170 ° C
(B-3)
L-lactic acid / ε-caprolactone copolymer grade name LCL (75:25) (manufactured by BM Co., Ltd.)
Weight average molecular weight = 400,000, Tm = 160 ° C

[Thermoplastic resin compositions (Examples 1 to 16), (Comparative Examples 1 to 5)]
Various methacrylic resins and aliphatic ester resins were dry blended with a tumbler in the blending amounts shown in Table 4 below, and melt kneaded in a φ30 mm twin screw extruder at the temperature set in Table 4. The strand was cooled and cut to obtain a pellet of a thermoplastic resin composition. In addition, Table 5 shows the physical property evaluation results of the respective thermoplastic resin compositions.
In Table 4, “Example” is abbreviated as “actual”, and “comparative example” is abbreviated as “ratio”.

In Examples 1 to 12, by combining a specific methacrylic resin and an aliphatic ester resin, it is possible to obtain a thermoplastic resin composition having excellent heat distortion resistance and practically sufficient impact strength. It was. Furthermore, the use of a specific methacrylic resin makes it possible to lower the set temperature during extrusion mixing, so that a thermoplastic resin composition excellent in recyclability can be obtained.
In Examples 13, 14, and 16, since the weight average molecular weight (Mw) of the methacrylic resin was slightly large, it was necessary to increase the extrusion temperature during kneading, and therefore a little recyclability compared to the other examples. However, other physical property values were sufficiently good for practical use.
In Example 15, since the molecular weight distribution (Mw / Mn) was around 5.0 and the abundance (%) of the molecular weight component of 1/5 or less of the Mp value was 28%, it was compared with the other examples. Although the recyclability was slightly reduced, other physical properties were sufficiently good for practical use.

  From the results described above, the use of an aliphatic ester resin with respect to a specific methacrylic resin enables mixing at low temperatures, and is a thermoplastic resin excellent in heat distortion resistance and impact strength specialized for recyclability. It became possible to obtain a composition. Therefore, it has become possible to develop applications for various food applications where cost performance is important.

In Comparative Examples 1 and 2, since the methacrylic resin in which the abundance (%) of the molecular weight component equal to or less than 1/5 of the Mp value of the methacrylic resin was less than 5% was used, the extrusion set temperature should not exceed 200 ° C. As a result, recyclability was not sufficient.
In Comparative Example 3, since the aliphatic ester resin was used at 100%, the impact strength was good, but the heat distortion resistance was lowered and the recyclability was slightly lowered.
In Comparative Example 4, since the abundance (%) of the molecular weight component of 1/5 or less of the Mp value of the methacrylic resin was as large as 43%, it was difficult to plasticize, and it was necessary to increase the set temperature, and sufficient recycling Sex was not obtained.
In Comparative Example 5, the resin 14 and the aliphatic ester resin were kneaded at a set temperature of the extruder of 180 ° C., but the plasticization of the methacrylic resin became insufficient, resulting in poor extrusion.

The thermoplastic resin composition of the present embodiment can be suitably used for various molded articles.
For example, furniture, household goods, storage and stockpiling equipment, toys and playground equipment, medical and welfare equipment, OA equipment, AV equipment, battery electrical equipment, lighting equipment, vehicle parts, especially automobile parts use, housing use, kitchen use, toilet It can be used for water applications such as baths and vanities. In particular, beverage cups and beverage bottles for dairy products, soft drinks and alcoholic beverages, soy sauce, sauces, mayonnaise, ketchup, containers for seasonings such as edible oil, containers for shampoos and rinses, cosmetic containers, It can be suitably used for resin containers with high recycling frequency such as agricultural chemical containers.

Claims (6)

Methacrylic acid ester monomer units 80 to 99.0 (mass%) and other vinyl monomer units 1.0 to 20 (mass%) copolymerizable with at least one methacrylic acid ester monomer; The weight average molecular weight measured by gel permeation chromatography (GPC) is 40000-250,000, and 7-40% of molecular weight components equal to or less than 1/5 of the peak molecular weight (Mp) obtained from the GPC elution curve are included. Methacrylic resin (A): 20-80% by mass,
Aliphatic polyester-based resin (B): 80 to 20% by mass;
A thermoplastic resin composition.   The thermoplastic resin composition according to claim 1, wherein the aliphatic polyester-based resin (B) is polylactic acid.   The methacrylic resin (A) has a weight average molecular weight of 40,000 to 150,000 measured by gel permeation chromatography (GPC), and a molecular weight component of 1/5 or less of the peak molecular weight (Mp) obtained from the GPC elution curve. The thermoplastic resin composition according to claim 1 or 2, which is a methacrylic resin contained in an amount of 7% to 20%. It is a manufacturing method of the thermoplastic resin composition as described in any one of Claims 1 thru | or 3, Comprising:
A monomer unit of 0 to 20 (mass%) composed of at least one methacrylate monomer unit of 80 to 100 (mass%) and another vinyl monomer copolymerizable with the methacrylate monomer. ), And a step of producing a polymer (I) having a weight average weight of 5000 to 50000 measured by gel permeation chromatography with respect to the entire methacrylic resin (A), 5 to 40 (mass%); ,
A raw material mixture containing a methacrylic acid ester is added in the presence of the polymer (I), and another vinyl monomer copolymerizable with the methacrylic acid ester monomer unit 80 to 99.5 (mass%) and the methacrylic acid ester. Polymer (II) containing 0.5 to 20 (% by mass) of monomer units composed of at least one monomer and having a weight average molecular weight of 60,000 to 300,000 is added to the entire methacrylic resin (A). On the other hand, a step of producing 95-60 (mass%)
A step of producing a methacrylic resin (A) by:
Kneading the methacrylic resin (A) and the aliphatic ester resin (B);
A process for producing a thermoplastic resin composition.   The molded article obtained by shape | molding the thermoplastic resin composition as described in any one of Claims 1 thru | or 3.   A cup for beverages obtained by molding the thermoplastic resin composition according to any one of claims 1 to 3.