JP2015227434A - Thermoplastic resin molded body for replacement of sanitary ware - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin molded body for replacement of sanitary ware capable of being molded by thermoplasticity, excellent in moldability, and excellent in pyrolytic resistance, concealment property and further solvent resistance during water absorption.SOLUTION: There is provide a thermoplastic resin molded body for replacement of sanitary ware containing a methacrylic resin (A): 100 pts.mass containing a methacrylic acid ester monomer unit of 80 to 99.9 mass%, at least one kind of other vinyl monomer unit capable of being copolymerized to the methacrylic acid ester monomer of 0.1 to 20 mass%, a light shielding additive (B): 0.1 to 2 pts.mass and a rubber copolymer (C): 6 to 50 pts.mass.

Description

  The present invention relates to a thermoplastic resin molded body for sanitary ware replacement.

  Conventionally, methacrylic resins represented by polymethyl methacrylate (PMMA) have high transparency, and thus are used in fields such as optical materials, vehicle parts, building materials, lenses, household goods, OA equipment, and lighting equipment. Widely used. As a typical example, it is used for vehicle materials, optical materials such as light guide plates and liquid crystal display films.

In addition, the surface hardness of methacrylic resin is higher than other general-purpose resins, and it is highly scratch resistant. Taking advantage of this high scratch resistance, various lighting covers that emphasize the appearance It is also used for protective sheets and films for displays. Furthermore, application development to a molded body requiring high appearance and high-class feeling that requires a certain degree of concealment is expected.
New applications expected in the future include, for example, water-use applications such as bathtubs, vanities, and kitchen counters, and various housings such as OA equipment, AV equipment, and game machines.
Furthermore, by adding various additives to the methacrylic resin having high transparency and excellent surface hardness for the purpose of coloring and concealment, a molded article having a higher appearance and a high-class feeling can be obtained.

  In the above-mentioned various applications, when obtaining a molded product by melt molding, especially a sanitary ware substitute application, it is a larger product than various miscellaneous goods members. Sex is required.

On the other hand, when a light shielding agent (hiding agent) is used as the additive, the following problems can be considered.
For example, there are problems such as decomposition of the light shielding agent itself, temperature rising / desorption of the adsorbing substance (water, etc.) of the light shielding agent, and generation of a gas derived from a decomposition product by the light shielding agent catalyzing polymer decomposition. When these problems occur, there is a possibility that the appearance becomes worse in the form of a bright spot or silver at the time of melt molding and deteriorates in appearance.
Also, when used as a molded product for use around water, the molded product absorbs water, so the effect of molding distortion is greater than before water absorption, and household goods (hairdressing, detergent, disinfectant, etc.) There is a risk of cracking of the molded body due to adhesion.
From the above, in the molded body used in the water application, in addition to excellent concealability, heat decomposition resistance and high solvent resistance are required.

Conventionally, a technique regarding an acrylic resin composition containing a granular additive having an elastic modulus of 15% or less of an acrylic resin and an inorganic filler subjected to a specific surface treatment, and a water product using the same is proposed. (For example, refer to Patent Document 1).
Moreover, the technique regarding the resin composition which aimed at the improvement of scratch resistance and impact resistance by silica addition, and the wash bowl and bathtub using the same is proposed (for example, refer patent document 2).

JP 2009-235208 A JP 2002-161182 A

However, although the acrylic resin composition disclosed in Patent Document 1 has improved impact strength and chemical crack resistance, sufficient characteristics have not been obtained for solvent resistance during water absorption. Moreover, since there are many use addition amounts of an inorganic filler, it is thought that heat-resistant decomposition property is inferior.
Further, the resin composition disclosed in Patent Document 2 is a resin composition for artificial marble typified by unsaturated polyester, and is not suitable as a material for melt molding such as injection molding or extrusion molding. The processability is inferior, and the relationship between the color additive and the heat decomposability is not sufficiently improved.

  Therefore, in the present invention, there is provided a thermoplastic resin substitute for sanitary ware that can be molded by thermoplastics, has good moldability, has good thermal decomposition resistance and concealment properties, and has excellent solvent resistance at the time of water absorption. The purpose is to do.

As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have found that a thermoplastic resin composition containing a methacrylic resin, a specific amount of a light shielding additive, and a rubbery copolymer. As a result, it was found that a molded article having excellent thermal decomposition resistance at the time of melt molding, high concealability, and high solvent resistance at the time of water absorption was obtained, and the present invention was completed.
That is, the present invention is as follows.

[1]
80 to 99.9% by weight of methacrylic acid ester monomer units and 0.1 to 20% by weight of at least one other vinyl monomer unit copolymerizable with the methacrylic acid ester monomers. And containing methacrylic resin (A): 100 parts by mass;
Light shielding additive (B): 0.1 to 2 parts by mass;
Rubber copolymer (C): 6 to 50 parts by mass,
A thermoplastic resin molded article for sanitary ware replacement.
[2]
The thermoplastic resin molded article for sanitary ware replacement according to [1], wherein the light shielding additive (B) is at least one selected from the group consisting of inorganic fillers and colorants.
[3]
The thermoplastic resin molded article for sanitary ware substitutes according to [1] or [2] above, wherein the rubbery copolymer (C) is rubber particles having a multilayer structure of two or more layers.
[4]
The methacrylic resin (A) is
The weight average molecular weight measured by gel permeation chromatography (GPC) is 50,000 to 250,000,
As described in any one of [1] to [3] above, which is a methacrylic resin containing 7 to 40% of a molecular weight component of 1/5 or less of the peak top molecular weight (Mp) obtained from the GPC elution curve. Thermoplastic resin molding for sanitary ware replacement.
[5]
Hygiene according to any one of [1] to [4], further comprising 0.1 to 10 parts by mass of the fluororesin (D) with respect to 100 parts by mass of the methacrylic resin (A). Thermoplastic resin molding for ceramics replacement.
[6]
The thermoplastic resin molded article for sanitary ware substitutes according to any one of [1] to [5], which is any one selected from the group consisting of a toilet bowl, a toilet bowl, a kitchen sink, and a bathtub.

  According to the present invention, it is possible to obtain a thermoplastic resin substitute for sanitary ware that is capable of being molded by thermoplastics, has excellent moldability, is excellent in heat-resistant decomposition, concealment, and solvent resistance at the time of water absorption. .

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 molding for sanitary ware replacement]
The sanitary ware substitute thermoplastic resin molding of the present embodiment is
Methacrylic acid ester monomer unit: 80 to 99.9% by mass, and at least one other vinyl monomer unit copolymerizable with the methacrylic acid ester monomer: 0.1 to 20% by mass Methacrylic resin (A) containing: 100 parts by mass;
Light shielding additive (B): 0.1 to 2 parts by mass;
Rubber copolymer (C): 6 to 50 parts by mass,
Containing.

The sanitary ware replacement thermoplastic resin molded body of the present embodiment means a thermoplastic resin molded body that can be used as an alternative to various members that have been used in the past.
In addition, “sanitary” of “sanitary ware” includes, for example, a wide range of applications around water and applications requiring concealment, such as housing applications, kitchens, toilets, baths, and vanities.

(Methacrylic resin (A))
The methacrylic resin (A) is a methacrylic acid ester monomer unit: 80 to 99.9% by mass, and at least one other vinyl monomer unit copolymerizable with the methacrylic acid ester monomer: 0.1 to 20% by mass.
That is, the methacrylic resin (A) contains 80 to 99.9% by mass of a methacrylic acid ester monomer and 0% of at least one other vinyl monomer copolymerizable with the methacrylic acid ester monomer. 0.1 to 20% by mass of a monomer component copolymer.

<Methacrylate monomer>
The methacrylic acid ester monomer forming the methacrylic acid ester monomer unit constituting the methacrylic resin (A) is not particularly limited as long as the effect of the present invention can be achieved. A preferred example is a monomer represented by 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.

Examples of the methacrylic acid ester monomer constituting the methacrylic resin (A) include, but are not limited to, butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, isopropyl methacrylate. , Cyclohexyl methacrylate, phenyl methacrylate, methacrylic acid (2-ethylhexyl), methacrylic acid (t-butylcyclohexyl), benzyl methacrylate, methacrylic acid (2,2,2-trifluoroethyl), and the like. One of them is methyl methacrylate.
The said methacrylic acid ester monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

Content of the methacrylic ester monomer which comprises methacrylic resin (A) is 80-99.9 mass% in methacrylic resin (A).
By setting the content of the methacrylic acid ester monomer in the methacrylic resin (A) to 80% by mass or more, excellent heat resistance is obtained in the thermoplastic resin molded article for sanitary ware replacement of the present embodiment, 99 Excellent fluidity can be obtained by adjusting the content to 9% by mass or less. Preferably it is 88-99 mass%, More preferably, it is 90-98 mass%.

<Other vinyl monomers copolymerizable with methacrylic acid ester monomers>
The other vinyl monomer that can be copolymerized with the above-mentioned methacrylic acid ester monomer constituting the methacrylic resin (A) is not limited to the following, but for example, the following general formula (2) The acrylate monomer represented by these is mentioned.

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. In particular, methyl acrylate, ethyl acrylate, and n-butyl acrylate are preferable, and methyl acrylate is more easily available and more preferable.

  Further, the vinyl monomer other than the acrylic ester monomer represented by the general formula (2), which can be copolymerized with the methacrylic ester monomer, is not limited to the following examples. For example, α, β-unsaturated acids such as acrylic acid and methacrylic acid, unsaturated group-containing dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, cinnamic acid, and alkyl esters thereof; styrene, o-methyl Styrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, styrene monomers such as о-ethylstyrene, p-tert-butylstyrene, isopropenyl benzene (α-methylstyrene); 1-vinylnaphthalene, -Aromatic vinyl compounds such as vinylnaphthalene, 1,1-diphenylethylene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene; 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-phenylmaleimide, N-cyclohexyl N-substituted maleimides such as maleimide; Amides such as acrylamide and methacrylamide; Ethylene glycol di (meth) acrylate, Diethylene glycol di (meth) acrylate Ester, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, etc., which are esterified with acrylic acid or methacrylic acid at both terminal hydroxyl groups; neopentyl glycol di (meth) One obtained by esterifying the hydroxyl group of two alcohols such as acrylate and di (meth) acrylate with acrylic acid or methacrylic acid; One obtained by esterifying a polyhydric alcohol derivative such as trimethylolpropane or pentaerythritol with acrylic acid or methacrylic acid A polyfunctional monomer such as divinylbenzene;

  Acrylic acid ester monomer copolymerizable with the above methacrylic acid ester monomer and vinyl monomers other than the above exemplified acrylic acid ester monomer may be used alone or in two kinds. A combination of the above may also be used.

Content of the other vinyl monomer unit which can copolymerize with the methacrylic acid ester monomer which comprises methacrylic resin (A) is 0.1-20 mass% in methacrylic resin (A). It is.
By replacing the content of other vinyl monomer units copolymerizable with the methacrylic acid ester monomer in the methacrylic resin (A) by 0.1% by mass or more, the sanitary ware substitute for this embodiment In the thermoplastic resin molded article, excellent fluidity and heat resistance can be obtained, and excellent heat resistance can be obtained by setting it to 20% by mass or less.
Preferably it is 1.0-15 mass%, More preferably, it is 1.5-12 mass%, More preferably, it is 2.0-10 mass%.

  In the methacrylic resin (A), a vinyl monomer copolymerizable with a methacrylic acid ester monomer other than the vinyl monomers exemplified above is used for the purpose of improving characteristics such as heat resistance and processability. You may add and copolymerize suitably.

<Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of methacrylic resin (A)>
The molecular weight and molecular weight distribution of the methacrylic resin (A) constituting the sanitary ware substitute thermoplastic resin molding of the present embodiment will be described.
The methacrylic resin (A) preferably has a weight average molecular weight (Mw) of 50,000 to 250,000 as measured by GPC (gel permeation chromatography).
In the thermoplastic resin molded article for sanitary ware substitutes of this embodiment, in order to obtain excellent mechanical strength and solvent resistance, the weight average molecular weight (Mw) of the methacrylic resin (A) is preferably 50000 or more, 70000 or more is more preferable, 80000 or more is further preferable, and 90000 or more is further more preferable.
In order for the methacrylic resin (A) to exhibit good fluidity, the weight average molecular weight (Mw) is preferably 250,000 or less, more preferably 210000 or less, further preferably 19000 or less, and further preferably 170000 or less. More preferred.
When the methacrylic resin (A) is in the range of the above-mentioned weight average molecular weight (Mw), in the thermoplastic resin molded article for sanitary ware replacement of the present embodiment, fluidity, mechanical strength, and solvent resistance. Can be balanced, and good moldability is maintained.
The weight average molecular weight of the methacrylic resin (A) can be measured by the method described in Examples described later.
The molecular weight distribution (Mw / Mn) of the methacrylic resin (A) is preferably 1.6 to 6.0, more preferably 1.7 to 5.0, and more preferably 1.8 to 5. More preferably, it is 0. When the molecular weight distribution of the methacrylic resin is 1.6 or more and 6.0 or less, the effect of being excellent in the balance between molding process flow and mechanical strength is obtained.

As described above, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the methacrylic resin (A) 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. A weight average molecular weight (Mw) and a number average molecular weight (Mn) of a predetermined methacrylic resin to be measured can be obtained based on a calibration curve obtained subsequently, and a molecular weight distribution is calculated from these. be able to.
The number average molecular weight (Mn) 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 (Mw) is defined as the average molecular weight by weight fraction.

<Abundance of molecular weight component of 1/5 or less of peak top molecular weight (Mp)>
The methacrylic resin (A) has a peak top molecular weight (Mp) present in the methacrylic resin (A) from the viewpoint of the solvent resistance of the thermoplastic resin molded article for sanitary ware replacement of this embodiment and the fluidity of the molding material. ) Is preferably 7 to 40%, more preferably 10 to 35%, and still more preferably 15 to 30%.
Here, the abundance (%) of the molecular weight component of 1/5 or less of the peak top molecular weight (Mp) is the peak top molecular weight (Mp) when the total area of the GPC elution curve is 100%. It is the ratio of the area area corresponding to a molecular weight component of 1/5 or less, and can be measured by the method described in [Example] described later.
In addition, the said peak top molecular weight (Mp) points out the weight molecular weight which shows a peak in a GPC elution curve.
When there are a plurality of peaks in the GPC elution curve, the molecular weight at the peak indicated by the weight molecular weight having the largest abundance is defined as the peak top molecular weight (Mp).
Good fluidity is obtained when the abundance of a molecular weight component of 1/5 or less of the peak top molecular weight (Mp) present in the methacrylic resin (A) is 7% or more. Good solvent resistance is obtained as it is 40% or less.

  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.

(Method for producing methacrylic resin (A))
The methacrylic resin (A) contained in the sanitary ware substitute thermoplastic resin molding of the present embodiment can be polymerized by any one of bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization, preferably, Bulk polymerization, solution polymerization, and suspension polymerization are preferable, and suspension polymerization is more preferable.
The polymerization temperature may be appropriately selected according to the polymerization method, and is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 60 ° C. or higher and 90 ° C. or lower.

In producing the methacrylic resin (A), a polymerization initiator may be used.
The polymerization initiator is not limited to the following, but when performing radical polymerization, 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, general radical polymerization initiator azo such as 2,2'-azobis-2-methylbutyronitrile and the like.
These may be used alone or in combination of two or more.
A combination of these radical polymerization initiators and an appropriate reducing agent may be used as a redox initiator.
These radical polymerization initiators and / or redox initiators are used in an amount 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 of the methacrylic resin (A). The range is generally selected and can be appropriately selected in consideration of the temperature at which the polymerization is carried out and the half-life of the polymerization initiator.

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

When producing the methacrylic resin (A), the molecular weight of the methacrylic resin (A) may be controlled within a range that does not impair the object of the present invention.
The method for controlling the molecular weight of the methacrylic resin (A) is not limited to the following. For example, chain transfer agents such as alkyl mercaptans, dimethylacetamide, dimethylformamide, triethylamine, dithiocarbamates, triphenyl Examples thereof include a method of controlling the molecular weight by using an iniferter such as methylazobenzene and a tetraphenylethane derivative. Moreover, it is also possible to adjust the molecular weight by adjusting these addition amounts.
The chain transfer agent is preferably an alkyl mercaptan from the viewpoint of handleability and stability, and the alkyl mercaptan is not limited to the following, and examples thereof include n-butyl mercaptan and 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) ) And the like.
These can be appropriately added according to the molecular weight of the target methacrylic resin (A), but in general, the total amount of all monomers used in the polymerization of the methacrylic resin (A) is 100. It is used in the range of 0.001 to 3 parts by mass with respect to parts by mass.
Examples of other molecular weight control methods include a method of changing the polymerization method, a method of adjusting the amount of the polymerization initiator, the above-described chain transfer agent, iniferter and the like, a method of changing various polymerization conditions such as the polymerization temperature, and the like. .
As these molecular weight control methods, only one type of method may be used alone, or two or more types may be used in combination.

  Further, as a method for producing a methacrylic resin in which the abundance of a molecular weight component of 1/5 or less of the peak top molecular weight (Mp) obtained from the GPC elution curve is in the range of 7 to 40%, a low molecular weight methacrylic resin is used. Examples thereof include a method of melt blending a resin and a high molecular weight methacrylic resin, a method of producing by a multistage polymerization method, and the like. The abundance of a molecular weight component of 1/5 or less of the peak top molecular weight (Mp) may be 7 to 40%, and the method is not particularly limited, but will be described later from the viewpoint of quality stability. It is preferred to use a multistage polymerization method.

  In the case of using the multistage polymerization method, first, in the first stage polymerization, the methacrylic acid ester monomer and at least one other vinyl monomer copolymerizable with the methacrylic acid ester monomer are used. It is preferable to produce 5 to 40% by mass of the polymer (I) having a weight average molecular weight of 5000 to 50000 measured by GPC with respect to the entire 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 polymer (II) having a weight average molecular weight of 60,000 to 350,000 is preferably produced in an amount of 95 to 60% by mass based on the entire target methacrylic resin (A).

A polymer (I) obtained by the first-stage polymerization and having a weight average molecular weight of 5000 to 50000 measured by GPC (hereinafter simply referred to as polymer (I)), and polymer (I). Polymer (II) obtained by the second stage polymerization having a weight average molecular weight of 60,000 to 350,000 by adding a raw material mixture containing a methacrylic acid ester in the presence (hereinafter simply referred to as polymer (II)). The blending ratio of the polymer (I) is 5 to 40% by mass from the viewpoint of improving the polymerization stability during production, the fluidity of the methacrylic resin, and the mechanical strength of the resin molded body. It is preferable that the ratio of (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) / polymer (II) is more preferably 10-40% by mass / 90-60% by mass, Preferably it is 15-35 mass% / 85-65 mass%, More preferably, it is 20-35 mass% / 80-65 mass%.

Further, the polymer (I) is a monomer unit composed of 80 to 100% by mass of a methacrylic acid ester monomer unit and at least one other vinyl monomer copolymerizable with the methacrylic acid ester. A polymer containing ˜20% by mass is preferred.
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.
In addition, from the viewpoints of suppressing defects such as silver during molding, polymerization stability, and fluidity, the weight average weight measured by GPC of the polymer (I) is preferably 5000 to 50000, and is preferably 10000 to 45000. It is more preferable that it is 20000-40000.
As described above, 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 a monomer 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. A polymer containing 0.5 to 20% by mass of a unit is preferable.
The ratio of the monomer units constituting the polymer (II) can be controlled by adjusting the amount of the monomer added in the polymerization step of the multistage polymer (II).
In addition, from the viewpoint of solvent resistance and fluidity, the weight average proportion measured by GPC of the polymer (II) is preferably 60000-350,000, more preferably 130,000-320,000, and more preferably 150,000- More preferably, it is 320,000, and even more preferably 150,000 to 300,000.
As described above, 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.

A polymer (I) using a methacrylic acid ester monomer alone in the first-stage polymerization step, or a methacrylic acid ester monomer and another vinyl monomer copolymerizable with at least one methacrylic acid ester. ).
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 are added, Although the polymer (II) is produced, this polymerization method makes it easy to control the composition of each of the polymer (I) and the polymer (II), suppresses the temperature rise due to heat generated during polymerization, and increases the viscosity in the system. Can also 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.

(Light shielding additive (B))
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment contains a light shielding additive (B).
The light-shielding additive (B) is not particularly limited as long as the concealing property of the sanitary ware substitute thermoplastic resin molding of the present embodiment is expressed, but the group consisting of an inorganic filler and a colorant It is preferably at least one selected from the group.

Examples of the inorganic filler include, but are not limited to, 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, zinc dioxide, calcium monohydrogen phosphate, wollastonite, silica, zeolite, alumina, alumina oxide, boehmite, aluminum hydroxide, titanium oxide, titanium dioxide, silicic acid, Silicon oxide, silicon dioxide, magnesium oxide, magnesium dioxide, calcium silicate, sodium aluminosilicate, magnesium silicate, barium sulfate, brass, copper, silver, aluminum, nickel, iron, iron oxide, graphite, carbon nanotube, calcium fluoride ,cloud , Montmorillonite, swelling fluorine mica, and apatite, and the like.
Only one type of inorganic filler may be used alone, or two or more types may be used in combination.
From the viewpoint of concealment and surface hardness, titanium dioxide, magnesium oxide, alumina oxide, aluminum hydroxide, zinc dioxide, silicic acid, barium sulfate, talc, kaolin, mica, calcium carbonate, wollastonite, silica, graphite, Carbon nanotubes and the like are preferably included.
In addition, these inorganic fillers may be appropriately subjected to surface treatment for the purpose of being more familiar with the methacrylic resin (A).

Examples of the colorant include, but are not limited to, perylene dyes, perinone dyes, pyrazolone dyes, methine dyes, coumarin dyes, quinophthalone dyes, quinoline dyes, anthraquinone dyes, anthraquinone Dyes, asdrapyridone dyes, thioindigo dyes, coumarin dyes, isoindolinone pigments, chicatopyrrolopyrrole pigments, condensed azo pigments, benzimidazolone pigments, dioxazine pigments, copper phthalocyanine pigments, Quinacridone pigment, nickel complex compound, zinc stearate, magnesium stearate, calcium stearate, aluminum stearate, polymethylsilsesquioxane, copper halide phthalocyanine, ethylenebisstearic acid amide, ultramarine, ultramarine violet, Tsu Chen black, acetylene black, furnace black, carbon black, liquid paraffin, silicone oil and the like.
Only one type of colorant may be used alone, or two or more types may be used in combination.
From the viewpoint of concealability, magnesium stearate, calcium stearate, zinc stearate, polymethylsilsesquioxane, ketjen black, carbon black, acetylene black and furnace black, liquid paraffin, silicon oil and the like are preferable.

The said light-shielding additive may be used individually by 1 type, and may be used in combination of 2 or more types.
In addition, when a combination of an inorganic filler and a colorant is used as the light shielding additive (B) and an organic dye is used as the colorant, the organic dye may be decomposed during molding. It is preferable to use, as a main component, a simple substance or a compound which is not an organic substance among the products, that is, the inorganic filler and the colorant. In particular, from the viewpoint of thermal decomposition resistance during molding, it is preferable to use a combination of inorganic oxides typified by inorganic oxides and inorganic dioxides.

As addition amount of the light-shielding additive (B) described above, 0.1 to 2 parts by mass, preferably 0.3 to 2 parts by mass, and preferably 0.5 to 100 parts by mass of the component (A). -2 mass parts is more preferable, and 0.5-1.5 mass parts is further more preferable.
By making it 2 parts by mass or less, the thermal decomposition resistance at the time of melt molding is improved, and for example, a high suppression effect on the occurrence of silver on the surface of the molded body is obtained. Moreover, by setting it as 0.1 mass part or more, the concealability excellent in the melt-molded body can be exhibited.
<Measurement method of content of light shielding additive (B) in thermoplastic resin molding for sanitary ware substitute>
An example of a method for measuring the content of the light shielding additive (B) in the thermoplastic resin substitute for sanitary ware according to this embodiment will be described below.
For example, a method using an ash content determination method by an ash method can be applied. That is, the molded piece of the sanitary ware substitute thermoplastic resin is burned in an electric furnace (650 ° C., 3 hours), and the mass of the incombustible material after removing the burned material (resin content) and the mass of the molded piece before combustion By calculating the amount of ash from the difference, the content of the light shielding additive (B) in the thermoplastic resin molded article for sanitary ware replacement can be calculated.
In addition, by performing elemental analysis of the incombustible material using SEM (scanning electron microscope) / EDX (energy dispersive X-ray analyzer), a light shielding additive (B) in the thermoplastic resin molded article for sanitary ware substitutes The component analysis can be performed.

(Rubber copolymer (C))
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment contains a rubbery copolymer (C).
The rubbery copolymer (C) is not particularly limited, and examples thereof include organic rubber particles having a multilayer structure such as general butadiene-based ABS rubber, acrylic-based, polyolefin-based, silicon-based, and fluorine rubber. Can be used.
The rubbery copolymer (C) is particularly preferably rubber particles having a multilayer structure of two or more layers, and has a multilayer structure of two or more layers from the viewpoint of compatibility with the methacrylic resin (A) described above. Acrylic multilayer rubber is more preferred. Furthermore, by using organic rubber particles having a multilayer structure of three layers or more than organic rubber particles having a two-layer structure, thermal deterioration during the molding process and deformation of the organic rubber particles due to heating are suppressed. It is particularly preferable because the heat resistance and thermal deformation tend to be suppressed.

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, and soft-hard-soft from the inside. -Hard, soft-hard-hard, soft-soft-hard, hard-soft-hard, hard-hard-soft-hard, hard-soft-hard-hard, etc., preferably hard layer from the inside-soft It is a particle having a three-layer structure formed in the order of layer-hard layer or a four-layer structure formed in the order of hard-hard-soft-hard, hard-soft-hard-hard.
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 acrylic rubber particles having a three-layer structure, the copolymer forming the central layer (b-ii) is excellent in the thermoplastic resin substitute for sanitary ware according to this embodiment. From the viewpoint of imparting high toughness, a copolymer exhibiting soft rubber elasticity is preferred.
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 more 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 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 a moderate crosslinking and a rubber elasticity effect. Is preferable because of a tendency to increase.

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

When organic rubber particles are used as the rubbery copolymer (C), the average particle diameter of the organic rubber particles is preferably 0.3 μm or less, more preferably 0.25 μm to 0.1 μm from the viewpoint of dispersibility. .
The average particle diameter of the organic rubber particles can be determined by the following method.
An emulsion containing organic rubber particles is sampled, diluted with water to a solid content of 500 ppm, and measured by measuring the absorbance at a wavelength of 550 nm using a UV1200V spectrophotometer (manufactured by Shimadzu Corporation). Get the value. Next, the absorbance is similarly measured for a sample whose particle diameter is measured from a transmission electron micrograph, a calibration curve is created, and the particle diameter can be obtained by using the calibration curve and the measured value.

The method for producing the organic rubber particles is not particularly limited, and known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be applied, and it is particularly preferable to obtain by emulsion polymerization.
When the organic rubber particles are formed of acrylic rubber particles having a three-layer structure, the monomer mixture of the innermost layer (bi) is first added in the presence of an emulsifier and a polymerization initiator to complete the polymerization. The monomer mixture of the central layer (b-ii) is added to complete the polymerization, and then the monomer mixture of the outermost layer (b-iii) is added to complete the polymerization. The particles can be obtained as a latex.
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.

The content of the rubbery copolymer (C) in the thermoplastic resin molded article for sanitary ware replacement of the present embodiment is 6 to 50 parts by mass with respect to 100 parts by mass of the component (A), and 6 to 40 Mass parts are preferred, 6-30 parts by mass are more preferred, 6-25 parts by mass are more preferred, 7-23 parts by mass are even more preferred, and 8-21 parts by mass are even more preferred.
By setting the content of the rubbery copolymer (C) to 50 parts by mass or less with respect to 100 parts by mass of the component (A), the heat-resistant decomposability of the thermoplastic resin molded article for sanitary ware replacement of the present embodiment When the amount is 6 parts by mass or more, the solvent resistance at the time of water absorption is improved.
<Measurement method of abundance of rubbery polymer (C) in thermoplastic resin molding for sanitary ware substitute>
An example of a method for measuring the content of the rubbery copolymer (C) in the thermoplastic resin molded article for sanitary ware replacement of the present embodiment will be described below.
The content of the rubbery copolymer (C) can be determined, for example, by measuring the amount of the acetone insoluble part of the sanitary ware replacement thermoplastic resin molding.
First, the molded piece of the sanitary ware replacement thermoplastic resin is precisely weighed (mass (W1)). This molded piece is put into a centrifuge tube, and then acetone is added to dissolve it, and the acetone soluble part is removed. The solvent is removed by a vacuum dryer, and after cooling, the acetone-insoluble portion as a residue is weighed (mass (W2)).
The content (mass%) of the acetone insoluble part (Y) = content of the rubbery copolymer (C) is calculated by the following formula.
Content of acetone insoluble part (Y) = W2 / W1 × 100 (mass%)
Further, when the light shielding additive (B) is an inorganic filler, the content of the rubbery copolymer (C) can be calculated by the following formula, where X is the ash content determined above.
Content of rubbery copolymer (C) = (W2-X) / W1 × 100 (mass%)
Furthermore, since the content (mass) of the methacrylic resin (A) is W1-W2-X, the light shielding additive (B) and the rubbery copolymer (C) in the thermoplastic resin molding for sanitary ware substitutes ) Of methacrylic resin can be calculated.

(Other components that can be mixed in thermoplastic resin moldings for sanitary ware substitutes)
The thermoplastic resin molded article for substituting sanitary ware of this embodiment may contain other additives other than the above-described components (A) to (C) as long as the object of the present invention is not impaired. In particular, it is preferable to add a heat stabilizer, an ultraviolet absorber, a flame retardant, and the like.

<Heat stabilizer>
Examples of the heat stabilizer include, but are not limited to, for example, antioxidants such as hindered phenol antioxidants and phosphorus processing stabilizers, and hindered phenol antioxidants are 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) -о-cresol, ethylenebis (oxy) Siethylene) 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>
Examples of ultraviolet absorbers include, but are not limited to, for example, 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.
Moreover, when 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 there is little adhesion of the UV absorber to the mold surface during injection molding, or less adhesion of the UV absorber to the roll during film 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 ultraviolet absorber preferably has a mass reduction rate of 50% or less, more preferably 30% or less, 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.

<Flame Retardant>
Examples of the flame retardant include, but are not limited to, for example, cyclic nitrogen compounds, phosphorus flame retardants, silicon flame retardants, caged silsesquioxanes or partial cleavage structures thereof, and silica flame retardants. It is done.
In the sanitary ware replacement thermoplastic resin molded article of the present embodiment, it is particularly preferable to add a flame retardant to impart flame retardancy.

<Other additives other than the above>
The thermoplastic resin molded article for sanitary ware substitutes of this embodiment has various properties within a range not impairing the effects of the present invention from the viewpoint of imparting other characteristics such as releasability, antistatic properties, rigidity and dimensional stability. Additives can be further added.
Examples of the other additives include, but are not limited to, plasticizers such as phthalic acid esters, fatty acid esters, trimellitic acid esters, phosphoric acid esters, and polyesters; higher fatty acids, Mold release agents such as higher fatty acid esters, higher fatty acid mono-, di-, or triglycerides; antistatic agents such as polyethers, polyether esters, polyether ester amides, alkyl sulfonates, alkyl benzene sulfonates, Stabilizers such as antioxidants and light stabilizers; flame retardant aids, curing agents, curing accelerators, conductivity imparting agents, stress relaxation agents, crystallization accelerators, hydrolysis inhibitors, lubricants, impact imparting agents, Sliding property improver, compatibilizer, nucleating agent, reinforcing agent, reinforcing agent, flow modifier, sensitizer, thickener, anti-settling agent, anti-sagging agent, filler, antifoaming agent, coupling , Rust inhibitors, antibacterial and antifungal, antifouling agent, conductive polymers.

<Other resins>
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment may contain a combination of conventionally known resins in addition to the above-described components (A) to (C) as long as melt molding is possible.
The resin to be used is not particularly limited, and conventionally 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), biodegradable resin, polycarbonate-ABS resin alloy, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate , Polytrimethylene 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, ABS resin and MBS resin are preferable for improving impact resistance, and polyester resin is preferable for improving chemical 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 resins.

<Fluorine resin (D)>
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment is, as the other resin, 0.1 to 10 parts by mass of a fluororesin (D) with respect to 100 parts by mass of the methacrylic resin (A), Furthermore, it can contain.
The fluororesin is not particularly limited as long as the effects of the present invention are not impaired. For example, polytetrafluoroethylene (tetrafluoroethylene resin, PTFE), trifluoroethylene chloride resin (PCTFE) , Tetrafluoroethylene hexafluoroethylene propylene resin (PFEP), vinyl fluoride resin (PVF), vinylidene fluoride resin (PVDF), ethylene difluoride dichloride resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride, polychlorotrifluoroethylene, chlorotrifluoroethylene-ethylene copolymer (ECTFE), etc. Can be mentioned
From the viewpoint of thermal decomposition resistance, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene hexafluoroethylene propylene resin (PFEP), tetrafluoro Ethylene resin (PTFE) or the like can be preferably used, and tetrafluoroethylene resin (PTFE) is particularly preferable.
When the tetrafluoroethylene resin is used as the fluorine-based resin, a tetrafluoroethylene homopolymer is typically used, but in addition to the tetrafluoroethylene as a monomer, a small amount of a modifier such as perfluoroolefin, It may be a copolymer of fluoroolefin, perfluorovinyl ether or the like.
From the viewpoint of handling, the form of the fluororesin is preferably powdered resin particles. The fluororesin powder can be obtained by emulsion polymerization or suspension polymerization of the above monomer.
Moreover, it is preferable that the addition amount of a fluorine resin (D) is 0.1-10 mass parts with respect to 100 mass parts of methacrylic resins (A) as mentioned above, More preferably, it is 0.1-7. Part by mass, more preferably 0.1 to 5 parts by mass. When the amount is 0.1 parts by mass or more, the surface hardness of the sanitary ware replacement thermoplastic resin molded body of the present embodiment is good, and when the amount is 10 parts by mass or less, the thermal decomposition resistance is good.

[Method of manufacturing thermoplastic resin molded article for sanitary ware replacement]
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment is prepared by first kneading the methacrylic resin (A), the light shielding additive (B), and the rubbery copolymer (C), and further appropriately. It can be obtained by kneading other additives and the above-mentioned other resins to obtain a thermoplastic resin composition, and molding this into a molded body having a desired shape.
As a kneading method, a conventionally known method may be used, and it is not particularly limited.
The methacrylic resin as component (A) can be produced by the method described in <Method for producing methacrylic resin> above.
As a kneading method, for example, kneading can be performed 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.
The kneading temperature may be in accordance with the preferred processing temperature of the polymer produced according to the present invention and other resins to be mixed, and is generally in the range of 140 to 300 ° C, preferably in the range of 180 to 280 ° C.

After obtaining a thermoplastic resin composition as described above, a molded product is obtained by molding the thermoplastic resin composition.
Examples of the molding method include injection molding, sheet molding, blow molding, injection blow molding, inflation molding, T-die molding, press molding, extrusion molding, and other methods such as pressure molding and vacuum molding. Sub-processing molding methods can also be used.
In particular, injection molding that requires fluidity is preferable, and effective for melt molding at high pressure and high speed.
A method of kneading and producing a thermoplastic resin composition using a kneader such as a heating roll, kneader, Banbury mixer, extruder, etc., cooling, pulverizing, and further molding by transfer molding, injection molding, compression molding, etc. Is also applicable.
The order of mixing the components is not particularly limited as long as the effect of the present invention can be achieved.

[Use]
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment is not limited to the following, but for example, it is used as a molded article for use around water, such as housing applications, kitchens, toilets, baths, bathroom vanities, etc. Can do.
In particular, concealment is required, and it can be suitably used for applications around water, such as kitchen sinks, toilet bowls, bathtubs, toilet bowls, etc., in applications having medium to large-sized molding, solvent resistance and mechanical strength.
The thermoplastic resin molded article for sanitary ware replacement of the present embodiment is appropriately subjected to surface functionalization treatment such as hard coat treatment, antireflection treatment, transparent conductive treatment, electromagnetic wave shielding treatment, gas barrier treatment, etc. according to the purpose. Can do.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the Example mentioned later.

[Raw materials used in Examples and Comparative Examples]
・ Methyl methacrylate (MMA): Asahi Kasei Chemicals (2.5 ppm of 2,4-dimethyl-6-tert-butylphenol) manufactured by Chugai Trading as a polymerization inhibitor What is being done)
-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: made by Japanese fats and oils Made by Nippon Kagaku Kogyo Co., Ltd., used as a suspending agent. Calcium carbonate: Made by Shiraishi Kogyo Co., Ltd., used as a suspending agent. Sodium lauryl sulfate, made by Wako Pure Chemical Industries, Ltd.

〔Measuring method〕
(I. Measurement method of weight average molecular weight and molecular weight distribution of methacrylic resin (A))
The weight average molecular weight and molecular weight distribution of the methacrylic resin (A) were measured using the following apparatus and conditions.
Measuring device: Tosoh Corporation gel permeation chromatography (HLC-8320GPC)
Column: 1 TSKgel SuperH2500, 2 TSKgel SuperHM-M, 1 TSKguardcolumn SuperH-H, connected in series In this column, the high molecular weight elutes quickly, 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
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.
In addition, since polymethyl methacrylate used for the standard sample for the calibration curve is a single peak, (Mp) is expressed as a peak molecular weight, and is distinguished from the expression “peak top molecular weight” when there are multiple peaks. .
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 sample 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 a calibration curve of a seventh-order approximation, the weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), GPC peak top molecular weight (Mp), and GPC of the methacrylic resin (A) The ratio (%) of the component having a molecular weight of 1/5 or less of the peak top molecular weight (Mp) was determined.

(II. Measurement of physical properties)
<(1) Measuring method of heat decomposability>
Using TG-DTA8120 (differential differential thermobalance, manufactured by Rigaku Corporation), measure the weight loss rate (%) when holding a measurement sample of 8 to 15 mg for 10 min in a nitrogen atmosphere at 250 ° C., Evaluation was made by the following ○ to ×.
The measurement sample was manufactured by cutting out a part of a molded body of 90 mm × 50 mm × 4 mmt.
○: Mass weight loss rate 0.5% or less △; Mass weight loss rate 0.5% to 1.0% or less ×; Mass weight loss rate 1.0% or more

<(2) Solvent resistance evaluation method (ethanol resistance test)>
Evaluation of the solvent resistance was carried out by using a resin composition produced in Examples and Comparative Examples described later, and producing a 100 mm × 100 mm × 2 mmt flat plate-shaped body and then immersing it in water for 24 hours at 23 ° C. The surface of the molded body was sprayed with disinfecting ethanol (76.9 to 81.4 v / v%), and a visual evaluation was performed to determine whether or not cracks occurred.
The following (circle)-x evaluation was performed as a criterion of visual evaluation.
(Double-circle): A crack is not confirmed visually.
○: A slight crack having a length of 1 mm or less was visually confirmed, but a crack exceeding 1 mm was not confirmed.
X: Cracks exceeding 1 mm in length were visually confirmed.

<(3) Concealment Evaluation Method (Total Light Transmittance)>
Using the resin compositions produced in the examples and comparative examples described later, a molded product of 90 mm × 50 mm × 4 mmt was produced, and the total light transmittance was measured. evaluated.
○: Total light transmittance 3.0% or less △; Total light transmittance 3.0 to 4.0% or less ×; Total light transmittance 4.0% or more

〔component〕
The methacrylic resin (A), the light shielding additive (B), and the rubbery copolymer (C) used as constituent components in Examples and Comparative Examples described below are described below.

(Methacrylic resin (A))
As the methacrylic resin (A), the resins (A-1) to (A-4) produced according to the following Production Examples 1 to 4 were used.

<Production Example 1>
In a container having a stirrer, ion exchange water: 2 kg, tribasic calcium phosphate: 65 g, calcium carbonate: 39 g, and sodium lauryl sulfate: 0.39 g were added to obtain a mixed solution (a).
Next, 26 kg of ion exchange water was charged 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 added.
Thereafter, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. After observing an exothermic peak, the temperature was raised to 92 ° C. at a rate of 1 ° C./min and aged for 60 minutes to substantially complete the polymerization reaction.
Next, in order to cool to 50 ° C. and dissolve the suspending agent, 20% by mass sulfuric acid was added, and then the polymerization reaction solution was passed through a 1.68 mm mesh sieve to remove aggregates. Washing and dehydration drying were performed to obtain polymer fine particles.
The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 240 ° C., and the strand was cooled and cut to obtain resin pellets (A-1).
The weight average molecular weight of the obtained pellet was 102,000, the peak top molecular weight (Mp) was 101,000, and the 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%.

<Production Example 2>
In a container having a stirrer, ion exchange water: 2 kg, tribasic calcium phosphate: 65 g, calcium carbonate: 39 g, and sodium lauryl sulfate: 0.39 g were added to obtain a mixed solution (b).
Next, 26 kg of ion exchange 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 added.
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.
Next, in order to cool to 50 ° C. and dissolve the suspending agent, 20% by mass sulfuric acid was added, and then the polymerization reaction solution was passed through a 1.68 mm mesh sieve to remove aggregates. Washing and dehydration drying were performed to obtain polymer fine particles.
The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 240 ° C., and the strands were cooled and cut to obtain resin pellets (A-2).
The weight average molecular weight of the obtained pellet was 1760, the peak top molecular weight (Mp) was 184,000, and the molecular weight distribution (Mw / Mn) was 1.85.
Furthermore, the abundance (%) of molecular weight components having an Mp value of 1/5 or less was 4.6%.

<Production Example 3>
In a container having a stirrer, ion exchange water: 2 kg, tribasic calcium phosphate: 65 g, calcium carbonate: 39 g, and sodium lauryl sulfate: 0.39 g were added to obtain a mixed liquid (c).
Next, 23 kg of ion exchange water was charged into a 60 L reactor and the temperature was raised to 80 ° C., and the mixture (c) and methyl methacrylate: 5.5 kg, lauroyl peroxide: 40 g, 2-ethylhexylthioglycolate : 90 g was charged.
Thereafter, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 80 minutes after the starting materials were added.
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 methyl methacrylate: 16.2 kg, methyl acrylate: 0.75 kg, lauroyl peroxide: 21 g, n-octyl mercaptan: 17.5 g were added. Subsequently, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 105 minutes after the starting materials were added.
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, after cooling to 50 ° C. and adding 20% by mass sulfuric acid to dissolve the suspending agent, the polymerization reaction solution is passed through a 1.68 mm mesh sieve to remove aggregates, and the resulting bead polymer is Washing and dehydration drying were performed to obtain polymer fine particles.
The obtained polymer fine particles were melt-kneaded with a φ30 mm twin screw extruder set at 240 ° C., and the strand was cooled and cut to obtain resin pellets (A-3).
The obtained beads had a weight average molecular weight of 172,000, a peak top molecular weight (Mp) of 197,000, and a molecular weight distribution (Mw / Mn) of 3.65.
Furthermore, the abundance (%) of a molecular weight component having an Mp value of 1/5 or less was 24.5%.

<Production Example 4>
In a container having a stirrer, ion exchange water: 2 kg, tribasic calcium phosphate: 65 g, calcium carbonate: 39 g, and sodium lauryl sulfate: 0.39 g were added to obtain a mixed liquid (d).
Next, 26 kg of ion exchange water was charged into a 60 L reactor and the temperature was raised to 80 ° C., and the mixture (d) and methyl methacrylate: 3.76 kg, ethyl acrylate: 0.1 kg, lauroyl peroxide: 27 g, 2-ethylhexyl thioglycolate: 62 g was added.
Thereafter, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 80 minutes after the starting materials were added. 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 methyl methacrylate: 17.4 kg, ethyl acrylate: 1.35 kg, lauroyl peroxide: 23 g, n-octyl mercaptan: 35 g were charged, Subsequently, suspension polymerization was carried out while maintaining the temperature at about 80 ° C. An exothermic peak was observed 105 minutes after the starting materials were added.
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, after cooling to 50 ° C. and adding 20% by mass sulfuric acid to dissolve the suspending agent, the polymerization reaction solution is passed through a 1.68 mm mesh sieve to remove aggregates, and the resulting bead polymer is Washing and dehydration drying were performed to obtain polymer fine particles.
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 (A-4).
The obtained beads had a weight average molecular weight of 118,000, a peak top molecular weight (Mp) of 125,000, and a molecular weight distribution (Mw / Mn) of 2.45.
Furthermore, the abundance (%) of a molecular weight component having an Mp value of 1/5 or less was 13.5%.

(Light shielding additive (B))
<Inorganic filler>
B-1; Titanium Co., Ltd., titanium RTC-30
B-2: Titanium TR840 manufactured by Fuji Titanium Industry Co., Ltd.
B-3: Sipron A, Sipron A
<Colorant>
B-4; manufactured by Momentive PMJ, Tospearl 2000B

(Rubber copolymer (C))
As the rubbery copolymer, (C-1) and (C-2) produced by the following production method (I) and production method (II) were used.

<Production Method (I) of Rubber Copolymer (C-1)>
Ion exchange water: 6868 mL and sodium dihexyl sulfosuccinate: 13.7 g were put into a reactor with a reflux condenser with an internal volume of 10 L, and the temperature was raised to 75 ° C. under a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. There was virtually no effect.
222 g of the mixture (I-1) consisting of methyl methacrylate: 907 g, butyl acrylate: 33 g, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole: 0.28 g and allyl methacrylate: 0.93 g Was added all at once, and 0.22 g of ammonium persulfate was added after 5 minutes.
Forty minutes later, the remaining 719 g of (I-1) was continuously added over 20 minutes, and held for another 60 minutes after the addition was completed.
Next, after adding 1.01 g of ammonium persulfate, butyl acrylate: 1067 g, styrene: 219 g, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole: 0.39 g, allyl methacrylate: 27.3 g The mixture (I-2) consisting of was continuously added over 140 minutes and held for an additional 180 minutes after the end of the addition.
Next, after adding ammonium persulfate: 0.30 g, methyl methacrylate: 730 g, butyl acrylate: 26.5 g, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole: 0.22 g, n -Octyl mercaptan: The mixture (I-3) consisting of 0.76 g was continuously added over 40 minutes, and after completion of the addition, the temperature was raised to 95 ° C and held for 30 minutes.
The polymer emulsion (latex) was poured into a 3% by weight sodium sulfate warm aqueous solution, salted and coagulated, and then dried after repeating dehydration and washing 5 times to obtain a rubbery copolymer (C-1). Got.
The rubbery copolymer (C-1) obtained had an average particle size of 0.23 μm.
The average particle size of the rubbery copolymer was determined as follows.
First, the obtained emulsion of rubbery copolymer is sampled, diluted with water to a solid content of 500 ppm, and the absorbance at a wavelength of 550 nm is measured using a UV 1200 V spectrophotometer (manufactured by Shimadzu Corporation). It was measured.
Using a calibration curve prepared based on the value obtained by measuring the absorbance in the same manner for a sample whose particle size was measured in advance from a transmission electron micrograph, the average particle size was calculated from the measured absorbance of the rubber copolymer emulsion. Asked.

<Production Example of Rubber Copolymer (C-2) (II)>
Ion exchange water: 4600 mL and sodium dioctylsulfosuccinate: 24 g as an emulsifier were charged into a reactor with a reflux condenser with an internal volume of 10 L, and the temperature was raised to 80 ° C. in a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. There was virtually no effect.
Subsequently, Rongalite reducing agent: 1.3 g was added as a reducing agent and dissolved uniformly.
As a first layer, a monomer mixture (II-1) of methyl methacrylate: 190 g, butyl acrylate: 2.5 g, allyl methacrylate: 0.2 g, diisopropylbenzene hydroperoxide: 0.2 g was added at 80 ° C. Polymerized. The reaction was complete in about 15 minutes.
Next, as a second layer, butyl acrylate: 1360 g, styrene: 320 g, polyethylene glycol diacrylate (molecular weight 200): 40 g, allyl methacrylate: 7.0 g, diisopropylbenzene hydroperoxide: 1.6 g, Rongalite reducing agent: 1 0.0 g of monomer mixture (II-2) was added dropwise over 90 minutes. The reaction was completed 40 minutes after the completion of the dropwise addition.
Next, as the third layer, the monomer mixture (II-3) of methyl methacrylate: 190 g, butyl acrylate: 2.3 g, diisopropylbenzene hydroperoxide: 0.2 g was dropped over 5 minutes, After completion of the addition, the reaction at this stage was completed in about 15 minutes.
Finally, as a third layer, two steps, a monomer mixture of methyl methacrylate: 380 g, methyl methacrylate: 4.6 g, diisopropylbenzene hydroperoxide: 0.4 g, n-octyl mercaptan: 1.2 g (II-4) ) Was added over 10 minutes. This step was complete in about 15 minutes.
The temperature was raised to 95 ° C. and held for 1 hour, and the resulting polymer emulsion (latex) was poured into a 0.5% aqueous solution of aluminum chloride to agglomerate the polymer, washed 5 times with warm water, and then dried. A rubbery copolymer (C-2) was obtained.
The rubbery copolymer (C-2) obtained had an average particle size of 0.1 μm.

(Fluorine resin (D))
D-1; manufactured by Kitamura Co., Ltd., KTL-2N
D-2; manufactured by Kitamura Co., Ltd., KTL-8HM

[Examples 1-16], [Comparative Examples 1-8]
(Mixture of methacrylic resin (A), light shielding additive (B), rubbery copolymer (C), fluorine resin (D))
According to the compounding ratio shown in Tables 1 and 2 below, 100 parts by weight of the methacrylic resin (A) is dried with a tumbler in various light shielding agents (B), a rubbery copolymer (C), and a fluororesin (D). After blending and premixing, the mixture was melt-kneaded with a twin screw extruder of φ30 mm set at 250 ° C., and the strands were cooled and cut to obtain methacrylic resin composition pellets.
Tables 1 and 2 below show the blending amounts of the methacrylic resin (A), the light shielding additive (B), the rubbery copolymer (C) and the fluororesin (D).
Moreover, the physical property evaluation result of each methacrylic resin composition molded body is shown in Table 3 below.

In Examples 1 to 3, 10, and 11, since the light shielding additive amount and the rubbery copolymer amount were appropriate, the molded product having heat-resistant decomposability, concealing property, and solvent resistance at the time of water absorption at a practical level. was gotten.
In Examples 4 and 5, compared with Example 1, the concealment property tended to be slightly lower, but a practical level of solvent resistance was exhibited.
In Examples 6, 7, 9, 12, and 13, the Mw of the methacrylic resin was appropriate, and the molecular weight component of 1/5 or less of Mp was 7 to 40%, and thus higher solvent resistance was exhibited.
In Example 8, compared with Example 6, the concealment property was slightly decreased, but higher solvent resistance was exhibited.
In Examples 14 to 16, the amount of the rubbery copolymer was slightly large, and the heat decomposability tended to be lower than that of Example 1, but very high solvent resistance was exhibited.

On the other hand, in Comparative Example 1, since the component (B) and the component (C) were not mixed, the concealability and solvent resistance were insufficient.
In Comparative Examples 2 to 4, since the amount of component (B) or component (C) added was not appropriate, the thermal decomposition resistance and solvent resistance were insufficient.
In Comparative Example 5, the amount of the component (C) was appropriate, but since the component (B) was not contained, the concealability was insufficient.
In Comparative Examples 6 and 7, the amount of component (B) was appropriate, but the amount of component (C) added was not appropriate, so the solvent resistance was insufficient.
In Comparative Example 8, the amount of component (B) was appropriate, but the amount of component (C) added was excessive, so the thermal decomposition resistance decreased.

  The thermoplastic resin molded body of the present invention can be suitably used as a melt-molded body for sanitary ware replacement. For example, molded objects for housing applications, kitchens, toilets, bathrooms, bathroom vanities, and other water-based applications, and those that require concealment and are medium to large-sized and have solvent resistance and mechanical strength. As a molded body for use around water such as kitchen sinks, toilet bowls, bathtubs, toilet bowls, etc., it has industrial applicability.

Claims (6)

80 to 99.9% by weight of methacrylic acid ester monomer units and 0.1 to 20% by weight of at least one other vinyl monomer unit copolymerizable with the methacrylic acid ester monomers. And containing methacrylic resin (A): 100 parts by mass;
Light shielding additive (B): 0.1 to 2 parts by mass;
Rubber copolymer (C): 6 to 50 parts by mass,
A thermoplastic resin molded article for sanitary ware replacement.   The thermoplastic resin molded article for sanitary ware replacement according to claim 1, wherein the light shielding additive (B) is at least one selected from the group consisting of an inorganic filler and a colorant.   The thermoplastic resin molded article for sanitary ware replacement according to claim 1 or 2, wherein the rubbery copolymer (C) is rubber particles having a multilayer structure of two or more layers. The methacrylic resin (A) is
The weight average molecular weight measured by gel permeation chromatography (GPC) is 50,000 to 250,000,
The sanitary ware according to any one of claims 1 to 3, wherein the sanitary ware is a methacrylic resin containing 7 to 40% of a molecular weight component of 1/5 or less of a peak top molecular weight (Mp) obtained from a GPC elution curve. Alternative thermoplastic resin molding.   The methacrylic resin (A): The sanitary ware substitute according to any one of claims 1 to 4, further comprising 0.1 to 10 parts by mass of a fluororesin (D) with respect to 100 parts by mass. Thermoplastic resin molded product.   The thermoplastic resin molded article for sanitary ware replacement according to any one of claims 1 to 5, which is any one selected from the group consisting of a toilet bowl, a toilet bowl, a kitchen sink, and a bathtub.