WO2020235575A1

WO2020235575A1 - Thermoplastic resin molded body and manufacturing method therefor

Info

Publication number: WO2020235575A1
Application number: PCT/JP2020/019850
Authority: WO
Inventors: 内田壮一; 三枝一範; 中谷和史
Original assignee: 株式会社カネカ
Priority date: 2019-05-21
Filing date: 2020-05-20
Publication date: 2020-11-26
Also published as: JPWO2020235575A1

Abstract

One or more embodiments of the present invention relates to a thermoplastic resin molded body 1 comprising: a body section 2 that is structured from a thermoplastic resin foamed body; and a reinforcing rib 3 that is formed on a back surface side of the body section 2. When viewed in a transverse cross-section of the reinforcing rib 3, a joining section of the reinforcing rib 3 and the body section 2 has a curved shape due to a base section of the reinforcing rib 3 expanding outward, and a tip end section of the reinforcing rib 3 has a radius of curvature Rb at both corner sections, or the entire tip end section has a circular arc shape. The thickness T1 of the body section 2 is 1.8mm to 6.0mm, the radius of curvature Ra of the joining section is 0.05mm to 2.2mm, and the ratio T3/T1 of the thickness T1 of the body section 2 and the maximum thickness T3 of the reinforcing rib 3 is greater than 0.25 and less than or equal to 0.75. Consequently, provided are a thermoplastic resin molded body that is lightweight, has high surface impact strength even in a low-temperature environment, and does not have visual defects such as sink marks, as well as a manufacturing method therefor.

Description

Thermoplastic resin molded product and its manufacturing method

The present invention relates to a thermoplastic resin molded product that can be suitably used for home appliances and automobile parts, and a method for manufacturing the same.

Light weight is required for parts used in home appliances and automobiles. Therefore, by using a foam molded product, lightness is imparted. For example, Patent Document 1 describes a thermoplastic resin foam molded product in which a rib or boss-shaped protrusion integrated with the foamed base material portion is provided on the foamed base material portion. Such protrusions secure the rigidity of the molded body as a whole and reinforce the molded body.

JP-A-2002-225165

In the thermoplastic resin foam molded product described in Patent Document 1, the joint portion between the protrusion and the foamed base material has a structure having a curvature R, but the reinforcing effect of the protrusion is insufficient in a low temperature environment. Therefore, further improvement is required.

In order to solve the above problems, the present invention provides a thermoplastic resin molded product which is lightweight, has high surface impact strength even in a low temperature environment, and has no appearance defects such as sink marks, and a method for producing the same.

In one or more embodiments, the present invention reinforces the main body portion made of a thermoplastic resin foam and the thermoplastic resin molded body provided with reinforcing ribs formed on the back surface side of the main body portion. When observing the cross section of the reinforcing rib, the root portion of the reinforcing rib bulges outward, so that the joint portion between the reinforcing rib and the main body portion has a curved shape, and the reinforcing rib has a curved shape. The tip portion has a radius of curvature at both corners or has an arc shape, the thickness T1 of the main body portion is 1.8 mm or more and 6.0 mm or less, and the radius of curvature Ra of the joint portion is 0. Thermoplastic resin molding having a thickness of 05 mm or more and 2.2 mm or less, and a ratio T3 / T1 of the thickness T1 of the main body to the maximum thickness T3 of the reinforcing rib being larger than 0.25 and 0.75 or less. Regarding the body.

The present invention also comprises, in one or more embodiments, the method for manufacturing a thermoplastic resin molded body, wherein the main body and reinforcing ribs are integrally molded by injection molding to obtain a thermoplastic resin molded body. The present invention relates to a method for producing a thermoplastic resin molded article containing.

According to the present invention, it is possible to provide a thermoplastic resin molded product that is lightweight, has high surface impact strength even in a low temperature environment, and has no appearance defects such as sink marks. Further, according to the production method of the present invention, it is possible to obtain a thermoplastic resin molded product which is lightweight and has high surface impact strength even in a low temperature environment.

FIG. 1 is a schematic perspective view of a thermoplastic resin molded product according to one or more embodiments of the present invention. FIG. 2 is a schematic cross-sectional view of a portion of the thermoplastic resin molded product in which reinforcing ribs are arranged according to one or more embodiments of the present invention. FIG. 3 is a schematic cross-sectional view of a portion of the thermoplastic resin molded product in which reinforcing ribs are arranged according to one or more embodiments of the present invention. FIG. 4 is a schematic cross-sectional view of a portion of the thermoplastic resin molded product in which reinforcing ribs are arranged according to one or more embodiments of the present invention. FIG. 5 is a schematic cross-sectional view of a portion of the thermoplastic resin molded product in which reinforcing ribs are arranged according to one or more embodiments of the present invention. FIG. 6 is a schematic cross-sectional view of a portion of the thermoplastic resin molded product of Comparative Example 1 in which reinforcing ribs are arranged. FIG. 7 is a schematic view of a test piece used for measuring the surface impact strength of an injection foam molded product, a is a schematic plan view of a design surface (cavity side), and b and c are non-design surfaces (respectively). It is a schematic plan view of (core side). FIG. 8 is a photograph (300 times) of the cross section of the central part of the main body of Example 1 observed with a scanning electron microscope (SEM).

The present inventors diligently studied in order to solve the above-mentioned problems. As a result, in the main body portion made of the thermoplastic resin foam and the thermoplastic resin molded body provided with the reinforcing ribs formed on the back surface side of the main body portion, the root portion of the reinforcing ribs is expanded outward. The joint between the reinforcing rib and the main body is formed into a curved shape, and the tip of the reinforcing rib is formed into a shape having radius of curvature Rb at both corners, or is formed into an arc shape and the thickness of the main body. T1 is 1.8 mm or more and 6.0 mm or less, the radius of curvature Ra of the joint is 0.05 mm or more and 2.2 mm or less, and the ratio of the thickness T1 of the main body to the maximum thickness T3 of the reinforcing rib T3 / T1 It has been found that the surface impact strength of the thermoplastic resin molded product can be improved even in a low temperature environment while reducing the weight of the thermoplastic resin molded product by making the value greater than 0.25 and 0.75 or less. In one or more embodiments of the present invention, the arcuate means all shapes similar to an arc, specifically a perfect circular arc (true arc) and a curved shape including a part of an ellipse. Includes (elliptical arc). In the following, unless otherwise specified, arcs include true arcs and elliptical arcs.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings and the like, but the present invention is not limited to the embodiments described below.

FIG. 1 is a schematic perspective view of a thermoplastic resin molded product according to one or more embodiments of the present invention. 2 to 5 are schematic cross-sectional views of a portion of the thermoplastic resin molded product in which reinforcing ribs are arranged according to one or more embodiments of the present invention.

As shown in FIG. 1, the thermoplastic resin molded product 1 has a main body portion 2 made of a thermoplastic resin foam and a back surface side (also referred to as a non-design surface side) of the main body portion 2. It is provided with a reinforcing rib 3 formed in. If the thermoplastic resin molded body 1 has a main body portion 2 and a reinforcing rib 3 formed on the back surface side of the main body portion 2, the shape and size of the main body portion 2 and the number of reinforcing ribs 3 are provided. And the arrangement location can be appropriately set according to the application of the thermoplastic resin molded product 1. In the thermoplastic resin molded body 1, the main body 2 may be made of a thermoplastic resin foam, and the reinforcing rib 3 may or may not be foamed.

The main body 2 may have a flat plate shape or a curved plate shape having a curved surface portion. Further, it may have concave portions, convex portions and the like so as to have a desired shape according to the purpose of use and the like. The thickness T1 of the main body 2 is 1.8 mm or more and 6.0 mm or less, preferably 1.8 mm or more and 5.5 mm or less, and more preferably 2.0 mm or more and 5.0 mm or less. It is possible to increase the lightness of the thermoplastic resin molded product and prevent sink marks from occurring on the surface side (also referred to as the design surface side) of the main body 2. In one or more embodiments 1 of the present invention, the thickness T1 of the main body portion can be obtained by arbitrarily selecting and measuring the thickness of the main body portion in which the reinforcing ribs are not formed at five points and averaging them. ..

The reinforcing rib 3 is not particularly limited as long as it has the effect of increasing the strength of the thermoplastic resin molded body 1. As shown in the schematic cross-sectional views (cross sections) of FIGS. 2 to 5, the root portion of the reinforcing rib 3 bulges outward, so that the joint portion between the reinforcing rib 3 and the main body 2 has a curved shape. It has become. Further, as shown in the schematic cross-sectional view (cross section) of FIG. 2, the tip portion of the reinforcing rib 3 has a radius of curvature Rb at each of both corner portions, or has a radius of curvature Rb, or FIGS. As shown in the schematic cross-sectional view (cross section), it has an arcuate shape. In FIG. 3, the tip of the reinforcing rib 3 has the shape of a true arc, and in FIGS. 4 and 5, the tip of the reinforcing rib 3 has the shape of an elliptical arc. When the root portion and the tip portion of the reinforcing rib 3 have such a shape, the surface impact strength of the thermoplastic resin molded product 1 at a low temperature can be increased. From the viewpoint of further increasing the surface impact strength of the thermoplastic resin molded product at a low temperature, it is preferable that the tip portion of the reinforcing rib 3 has an arc shape as shown in FIGS. 3 to 5.

The radius of curvature Ra of the joint between the reinforcing rib 3 and the main body 2 is 0.05 mm or more and 2.2 mm or less, preferably 0.05 mm or more and 2.0 mm or less, and more preferably 0.05 mm or more and 1.8 mm. It is less than or equal to, more preferably 0.1 mm or more and 1.5 mm or less, and even more preferably 0.1 mm or more and 1.3 mm or less. When the radius of curvature Ra is in the above range, the surface impact strength of the thermoplastic resin molded product at a low temperature can be increased.

The ratio T3 / T1 of the thickness T1 of the main body and the maximum thickness T3 of the reinforcing rib 3 is larger than 0.25 and 0.75 or less, preferably 0.3 or more and 0.70 or less, and more preferably 0. It is 0.3 or more and 0.65 or less. When T3 / T1 is in the above-mentioned range, the weight of the thermoplastic resin molded product can be increased, and the occurrence of sink marks on the design surface can be effectively suppressed. In one or more embodiments of the present invention, the maximum thickness T3 of the reinforcing ribs means the maximum thickness of the root portion of the reinforcing ribs.

The average thickness T2 of the portion of the reinforcing rib 3 excluding the tip portion and the root portion (hereinafter, also simply referred to as the average thickness T2 of the reinforcing rib 3) is not particularly limited, but for example, the low temperature of the thermoplastic resin molded product. From the viewpoint of easily increasing the surface impact strength in the above and easily suppressing the occurrence of sink marks on the design surface, it is preferably 0.2 mm or more and 4.3 mm or less, more preferably 0.2 mm or more and 4.0 mm or less, and further. It is preferably 0.2 mm or more and 3.5 mm or less. The average thickness T2 of the reinforcing rib 3 can be calculated by the following mathematical formula (1).
T2 = T3-2 x Ra (1)

As shown in FIG. 2, when the tip of the reinforcing rib 3 has a radius of curvature Rb at both corners, Rb is preferably larger than 0 mm and smaller than T2 / 2. Specifically, the radius of curvature Rb of the corner portion is preferably 0.05 mm or more and 1.5 mm or less, more preferably 0.05 mm or more and 1.3 mm or less, and further preferably 0.1 mm or more 1 .2 mm or less.

As shown in FIG. 2, when the tip of the reinforcing rib 3 has a radius of curvature Rb at both corners, the tip of the reinforcing rib 3 may have a flat portion at the center. .. In this case, the thickness T4 of the flat portion at the tip of the reinforcing rib 3 can be calculated by the following mathematical formula (2).
T4 = T2-2 × Rb (2)

As shown in FIG. 3, when the tip of the reinforcing rib 3 has the shape of a true arc, the radius of curvature Rc of the true arc is equal to T2 / 2. In that case, the radius of curvature Rc is preferably 0.05 mm or more and 2.2 mm or less, more preferably 0.05 mm or more and 2.0 mm or less, and further preferably 0.1 mm or more and 1.5 mm or less.

As shown in FIG. 4 or 5, when the tip of the reinforcing rib 3 has an elliptical arc shape, the radius of curvature Rd of the elliptical arc is the length of T2 determined by the ratio of T3 / T1 and Ra. It may be set based on an appropriately set rib height, and the angle of the elliptical arc may be an acute angle or an obtuse angle. The radius of curvature Rd of the elliptical arc is, for example, preferably 0.05 mm or more and 9.5 mm or less, more preferably 0.05 mm or more and 8.0 mm or less, and preferably 0.1 mm or more and 7.0 mm or less. It is even more preferably 0.1 mm or more and 5.0 mm or less.

The height H of the reinforcing rib 3 is not particularly limited, and may be appropriately set according to the application of the thermoplastic resin molded body 1 and the arrangement location of the reinforcing rib 3. For example, from the viewpoint of strength reinforcement, weight reduction, and mold releasability during actual molding, the height H of the reinforcing rib 3 is preferably 2 mm or more and 15 mm or less, and preferably 2 mm or more and 10 mm or less. More preferably, it is 2 mm or more and 7 mm or less.

The ratio H / T2 of the height H of the reinforcing rib 3 to the average thickness T2 of the reinforcing rib 3 is preferably 0.4 or more and 75 or less, preferably 0.5 or more, from the viewpoint of achieving both weight reduction and strength reinforcement. It is more preferably 50 or more, more preferably 1.0 or more and 35 or less, particularly preferably 1.5 or more and 20 or less, and further particularly preferably 2.0 or more and 10 or less.

The reinforcing ribs 3 may be formed on the non-design surface side of the thermoplastic resin molded body 1, and the number and specific arrangement locations thereof are appropriately set according to the application of the thermoplastic resin molded body 1 and the like. do it. From the viewpoint of enhancing the reinforcing effect, the reinforcing rib 3 preferably has an elongated plate shape in which the longitudinal direction is arranged along the longitudinal direction of the thermoplastic resin molded body 1. The length (length in the longitudinal direction) of the reinforcing rib 3 is not particularly limited, and is appropriately adjusted according to the length of the thermoplastic resin molded body, for example, the resin part requiring reinforcement and the required degree of reinforcement. However, from the viewpoint of effectively reinforcing the strength of the entire resin component, it is desirable that the length is equal to that of the resin component. When the thermoplastic resin molded body is a resin part for automobile use, the thermoplastic resin molded body is usually provided with a clip seat for joining with a metal chassis, and is used for reinforcement at a place where stress is applied during attachment / detachment. The ribs may be set preferentially. From the viewpoint of further increasing the surface impact strength immediately below the reinforcing rib 3 at a low temperature and its surroundings, the widthwise spacing between adjacent reinforcing ribs is set based on the spread of the stress distribution when an impact is applied. Is preferable. Specifically, it is preferable to install them at intervals so that the ends of the spreads of the stress distributions (the most stressed ends) of the adjacent reinforcing ribs overlap. By installing in such a way, the reinforcing effect is enhanced. For example, the widthwise distance between adjacent reinforcing ribs is preferably 3 mm or more and 20 mm or less, more preferably 5 mm or more and 15 mm or less, and further preferably 5 mm or more and 10 mm or less.

The length (length in the longitudinal direction) of the thermoplastic resin molded product 1 is preferably 200 mm or more and 3000 mm or less, more preferably 300 mm or more and 2500 mm or less, and the width is preferably 50 mm or more and 3000 mm or less. It is more preferably 50 mm or more and 2500 mm or less. When the length and the width are the same size, one of them may be the length and the other may be the width.

The thermoplastic resin molded product 1 can be composed of a thermoplastic resin composition. The thermoplastic resin used in the thermoplastic resin composition is not particularly limited, and for example, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene, ABS resin, acrylic resin, polyethylene terephthalate (PET). General-purpose thermoplastic resins such as, polyamide (PA), polycarbonate (PC), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), engineering resins such as cycloolefin polymer (COP), polyphenylene sulfide (PPS), etc. Polyetherketone (PEK), polyetheretherketone (PEEK), polytetrafluoroethylene, thermoplastic polyimide, polyallylate (PAR), polysalphon (PSU), polyethersalphon (PES), liquid crystal polymer (LCP), heat Examples thereof include super engineering resins such as thermoplastic polyimide (PI).

A polymer alloy may be used as the thermoplastic resin. Examples of the polymer alloy include polyphenylene ether (PPE) -based alloys, PA-based alloys, PC-based alloys, PBT-based alloys, ABS and polyolefin alloys, and the like. Examples of the PC-based alloy include an alloy of polycarbonate and ABS, an alloy of polycarbonate and thermoplastic polyester, an alloy of polycarbonate and polypropylene, and the like.

As the above-mentioned thermoplastic resin, one type may be used alone, or two or more types may be used in combination.

Among them, when the thermoplastic resin molded body 1 is a part for a vehicle such as an automobile, the thermoplastic resin includes polycarbonate, heat-resistant ABS resin, polycarbonate and ABS alloy (PC / ABS), and, from the viewpoint of heat resistance. It is preferable to use one or more selected from the group consisting of polycarbonate and polyethylene terephthalate alloy (PC / PET), and it is more preferable to use PC / PET.

When the thermoplastic resin composition is a polycarbonate resin composition containing a polycarbonate resin such as polycarbonate, an alloy of polycarbonate and ABS (PC / ABS), and an alloy of polycarbonate and polyethylene terephthalate (PC / PET), the above. The polycarbonate-based resin composition preferably contains heat-expandable microcapsules as a foaming agent from the viewpoint of improving the appearance of the thermoplastic resin molded product, and more preferably a master batch containing the heat-expandable microcapsules. It is preferable to include it.

As the master batch, for example, one containing a heat-expandable microcapsule and a carrier resin composition can be used.

The heat-expandable microcapsules are capsule-shaped foaming agents in which a liquid low boiling point compound is wrapped in a thermoplastic polymer shell, and are vaporized by heating during molding such as heating in a cylinder of an injection molding machine. The pressure of the inflated capsule functions as a foaming agent. As the heat-expandable microcapsules, for example, those described in Japanese Patent Application Laid-Open No. 2011-16884 may be preferably used. Specifically, the heat-expandable microcapsules have a core-shell structure, the core is composed of one or more compounds having a boiling point of 10 ° C. or higher and 330 ° C. or lower, and the shell contains the core and is thermoplastic. It is preferably composed of a resin.

The core may be composed of one or more selected from compounds having a boiling point of 10 ° C. or higher and 330 ° C. or higher. The compound constituting the core is not particularly limited, and examples thereof include hydrocarbons, alcohols, ketones and the like. Hydrocarbons are not particularly limited, but for example, pentane, hexane, heptane, octane, nonan, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eikosan, and these. Examples include structural isomers of hydrocarbons. The compound constituting the core is preferably one or more hydrocarbons having a boiling point of 10 ° C. or higher and 330 ° C. or lower, more preferably one or more hydrocarbons having a boiling point of 30 ° C. or higher and 280 ° C. or lower, and further. It is preferably one or more hydrocarbons having a boiling point of 30 ° C. or higher and 200 ° C. or lower. By using a compound having a boiling point of 10 ° C. or higher, it is easy to master-batch heat-expandable microcapsules. Further, by using a compound having a boiling point of 330 ° C. or lower, the dispersibility is improved during polymerization, and it is easy to produce thermally expandable microcapsules.

Examples of the monomer component of the thermoplastic resin constituting the shell of the heat-expandable microcapsule include a nitrile-based monomer, a (meth) acrylate-based monomer, an aromatic vinyl-based monomer, and a diene-based monomer. A group consisting of a body, a vinyl-based monomer having a carboxyl group, and a monomer having one or more reactive functional groups selected from the group consisting of a methylol group, a hydroxyl group, an amino group, an epoxy group, and an isocyanate group. One or more monomers selected from the above can be used.

Examples of the nitrile-based monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, fumaronitrile, and the like.

Examples of the (meth) acrylate-based monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl. Examples thereof include (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate. In the present invention, the "(meth) acrylate" may be a methacrylate or an acrylate.

Examples of the aromatic vinyl-based monomer include styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, p-nitrostyrene, chloromethylstyrene and the like.

Examples of the diene-based monomer include butadiene, isoprene, and chloroprene.

Examples of the vinyl monomer having a carboxyl group include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, etaclilic acid, crotonic acid and silicic acid, maleic acid, itaconic acid, fumaric acid, citraconic acid and chloromalein. Unsaturated dicarboxylic acids such as acids and their anhydrides, monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, monoethyl fumarate, monomethyl itaconic acid, monoethyl itaconic acid, monobutyl itaconic acid and other unsaturated dicarboxylic acids. Examples include monoesters.

A monomer having one or more reactive functional groups selected from the group consisting of a methylol group, a hydroxyl group, an amino group, an epoxy group, and an isocyanate group (hereinafter, simply "a monomer having a reactive functional group"). Also referred to as), for example, N-methylol (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, vinyl glycidyl ether, propenyl glycidyl ether, glycidyl. Examples thereof include (meth) acrylate, glycerin mono (meth) acrylate, 4-hydroxybutylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, p-hydroxystyrene, blocked isocyanate and the like. Examples of the blocked isocyanate include phenol, alcohol, dimethyl malonate, diethyl malonate, ethyl acetoacetate, oxime, dimethylpyrazole, etc. of isocyanate compounds (diphenylmethane diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, etc.). Examples thereof include blocked isocyanates such as methyl ethyl ketone oxime and caprolactam. In the present invention, "(meth) acrylamide" may be methacrylamide or acrylamide.

From the viewpoint of suppressing the decomposition of the main chain of the thermoplastic resin component such as polycarbonate by the shell of the heat-expandable microcapsules, the thermoplastic resin constituting the shell is the above-mentioned nitrile-based monomer, (meth). It is preferable to contain at least one selected from the group consisting of an acrylate-based monomer, an aromatic vinyl-based monomer, and a vinyl-based monomer having a carboxyl group. Further, the thermoplastic resin constituting the shell may appropriately contain a chain transfer agent and a monomer having a reactive functional group.

The chain transfer agent may be any one used in ordinary radical polymerization and is not particularly limited. Specifically, a mercaptan-based compound can be used. Examples of the mercaptan compound include alkyl mercaptans such as n-dodecyl mercaptan, n-octyl mercaptan, t-dodecyl mercaptan, n-octadecyl mercaptan, 2-mercaptobenzothiazole, bromtrichloromethane, α-methylstyrene dimer and thioglycol 2-Ethylhexyl acid or the like can be preferably used.

The heat-expandable microcapsules preferably have an average particle size (when unexpanded) of 0.5 μm or more and 50 μm or less, more preferably 0.7 μm or more and 50 μm or less, and further preferably 1.0 μm or more and 45 μm. It is less than or equal to, more preferably 1.0 μm or more and 40 μm or less, and particularly preferably 1.0 μm or more and 35 μm or less. The maximum particle size of the heat-expandable microcapsules when heated is in the range of about 3 times or more and 5 times or less from the average particle size when not expanded. If the average particle size when not expanded is 0.5 μm or more and 50 μm or less, the particle size when expanded is approximately 1.5 μm or more and 250 μm or less, and the Charpy impact strength and surface impact strength during foaming are significantly reduced. It can be suppressed. The average particle size of the heat-expandable microcapsules when not expanded can be measured with a particle size distribution measuring device, specifically, a particle size distribution measuring device SALD-3000J manufactured by Shimadzu Corporation.

The maximum expansion temperature (also referred to as the maximum foaming temperature) of the heat-expandable microcapsules is preferably 180 ° C. or higher and 300 ° C. or lower, more preferably 190 ° C. or higher and 290 ° C. or lower, and further preferably 200 ° C. or higher and 280 ° C. It is ℃ or less, and particularly preferably 210 ℃ or more and 270 ℃ or less. The maximum expansion temperature of the heat-expandable microcapsules can be measured by the measuring method described in Japanese Patent No. 5484673. Specifically, "TMA measurement" is performed using a TMA-7 type manufactured by Birkin Elmer. When about 0.25 mg of the sample is placed in a container, the temperature is raised at a temperature rising rate of 5 ° C./min, the displacement of the height is continuously measured, and the displacement of the height of the sample in the container is maximized. Let the temperature of be the maximum expansion temperature. When the maximum expansion temperature of the heat-expandable microcapsules is in the above range, it matches the molding temperature of polycarbonate, so that an injection-foamed molded product having low density and high strength can be easily obtained.

The carrier resin composition is preferably substantially compatible with polycarbonate from the viewpoint of obtaining a thermoplastic resin molded product having a good appearance. In the present invention, "substantially compatible with polycarbonate" means that, specifically, in differential scanning calorimetry (DSC) of a mixture of a carrier resin composition and polycarbonate, the peak of the glass transition temperature becomes one. To say.

The shear viscosity of the carrier resin composition at 130 ° C. is preferably 1.0 × 10 ² Pa · s or more and 1.0 × 10 ⁶ Pa · s or less. When the shear viscosity of the carrier resin composition at 130 ° C. is 1.0 × 10 ² Pa · s or more and 1.0 × 10 ⁶ Pa · s or less, the heat-expandable microcapsules are uniform in the carrier resin composition. It becomes easier to obtain master batches distributed in. From the viewpoint of improving the processability of master batching, the shear viscosity of the carrier resin composition at 130 ° C. is preferably 1.0 × 10 ³ Pa · s or more and 9.0 × 10 ⁵ Pa · s or less. It is more preferably 0 × 10 ³ Pa · s or more and 6.0 × 10 ⁵ Pa · s or less, still more preferably 3.0 × 10 ³ Pa · s or more and 3.0 × 10 ⁵ Pa · s or less, and even more preferably. Is 5.0 × 10 ³ Pa · s or more and 1.5 × 10 ⁵ Pa · s or less. The shear viscosity of the carrier resin composition at 130 ° C. can be measured using a flow tester (model CFT-500C) manufactured by Shimadzu Corporation. Specifically, the measurement start temperature is set to 50 ° C., and a constant load of 30 kgf is applied to the carrier resin composition to flow the carrier resin composition in a capillary having a diameter of 1.0 mm and a length of 10 mm, and the temperature is raised at 10 ° C./min to measure the temperature. The shear viscosity at the time when becomes 130 ° C. is measured.

From the viewpoint of improving the low temperature processability of the master batch, the carrier resin composition has a shear viscosity of 1.0 × 10 ² Pa · s or more and 1.0 at any temperature in the temperature range of 40 ° C. or more and 100 ° C. or less. It is preferably × 10 ⁶ Pa · s or less, more preferably 1.0 × 10 ³ Pa · s or more and 9.0 × 10 ⁵ Pa · s or less, and 2.0 × 10 ³ Pa · s or more 6. It is more preferably 0 x 10 ⁵ Pa · s or less, still more preferably 3.0 × 10 ³ Pa · s or more and 3.0 × 10 ⁵ Pa · s or less, and particularly preferably 5.0 × 10 ³ Pa · s. It is 1.5 x 10 ⁵ Pa · s or less.

The carrier resin composition contains polystyrene having a weight average molecular weight of 1,000 or more and less than 180,000 (hereinafter, also referred to as carrier resin composition (B1)), or the carrier resin composition is polystyrene and weight average. Acrylic containing an acrylic plasticizer having a molecular weight of 1,000 or more and 20,000 or less (hereinafter, also referred to as carrier resin composition (B2)) or having a weight average molecular weight of 8,000 or more and 350,000 or less. It preferably contains a based resin and an acrylic plasticizer having a weight average molecular weight of 1,000 or more and 20,000 or less (hereinafter, also referred to as a carrier resin composition (B3)). In the present invention, the weight average molecular weight and the number average molecular weight of the resin are measured by GPC (gel permeation chromatography).

<< Carrier resin composition (B1) >>
The carrier resin composition (B1) contains polystyrene having a weight average molecular weight of 1,000 or more and less than 180,000. As a result, the carrier resin composition (B1) can easily satisfy the range in which the shear viscosity at 130 ° C. is 1.0 × 10 ² Pa · s or more and 1.0 × 10 ⁶ Pa · s or less. It is preferable that the carrier resin composition (B1) does not substantially contain an acrylic plasticizer having a weight average molecular weight of 1,000 or more and 20,000 or less. Here, "substantially free" means that the carrier resin composition (B1) contains 0 parts by weight or more of an acrylic plasticizer having a weight average molecular weight of 1,000 or more and 20,000 or less with respect to 100 parts by weight of polystyrene. It means that it contains less than 3 parts by weight, preferably less than 1 part by weight.

In the carrier resin composition (B1), polystyrene may have a weight average molecular weight of 1,000 or more and less than 180,000, and is not particularly limited. The polystyrene may be a homopolymer of one kind of styrene-based monomer, or may be a copolymer of two or more kinds of styrene-based monomers. Further, it may be a copolymer of another monomer copolymerizable with the styrene-based monomer, and in that case, the repeating unit derived from styrene is contained in an amount of 50% by weight or more in all the repeating units. However, it is preferably contained in an amount of 80% by weight or more.

Examples of the styrene-based monomer include styrene and styrene-based derivatives. Examples of the styrene derivative include methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, bromostyrene, dibromostyrene, tribromostyrene, chlorostyrene, dichlorostyrene, trichlorostyrene and the like. Of these, styrene is preferable.

Examples of the other copolymerizable monomer include polyfunctional vinyl compounds such as divinylbenzene; acrylate, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylonitrile and the like. Examples thereof include (meth) acrylic compounds; diene compounds such as budadiene and derivatives thereof; unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. These can be used alone or in combination of two or more.

From the viewpoint of processability, the polystyrene is preferably a homopolymer of styrene.

In the carrier resin composition (B1), the weight average molecular weight of polystyrene is preferably 150,000 or less, more preferably 130,000 or less, and 100,000 or less, from the viewpoint of enhancing compatibility with polycarbonate. It is more preferably less than or equal to, even more preferably 80,000 or less, and particularly preferably 40,000 or less. Further, from the viewpoint of improving the processability of the masterbatch, the weight average molecular weight of polystyrene is preferably 2,000 or more, more preferably 5,000 or more, and preferably 10,000 or more. More preferred.

The polystyrene is not particularly limited, but the glass transition temperature is preferably 15 ° C. or higher and 130 ° C. or lower. When the glass transition temperature of the polystyrene is 15 ° C. or higher, it is easy to control the temperature of the extruder at the time of producing the masterbatch, and the workability is improved. Further, when the glass transition temperature of the polystyrene is 130 ° C. or lower, the carrier resin composition (B1) tends to have an appropriate viscosity during the production of the masterbatch, so that the heat-expandable microcapsules do not rupture. , Workability is improved.

<< Carrier resin composition (B2) >>
The carrier resin composition (B2) contains polystyrene and an acrylic plasticizer having a weight average molecular weight of 1,000 or more and 20,000 or less.

In the carrier resin composition (B2), polystyrene is not particularly limited, and may be a homopolymer of one kind of styrene-based monomer, or a copolymer of two or more kinds of styrene-based monomers. You may. Further, it may be a copolymer of another monomer copolymerizable with the styrene-based monomer, and in that case, the repeating unit derived from styrene is contained in an amount of 50% by weight or more in all the repeating units. However, it is preferably contained in an amount of 80% by weight or more.

The polystyrene is not particularly limited, but the glass transition temperature is preferably 15 ° C. or higher and 130 ° C. or lower. When the glass transition temperature of the polystyrene is 15 ° C. or higher, it is easy to control the temperature of the extruder at the time of producing the masterbatch, and the workability is improved. Further, when the glass transition temperature of the polystyrene is 130 ° C. or lower, the carrier resin composition (B2) tends to have an appropriate viscosity during the production of the masterbatch, so that the heat-expandable microcapsules do not rupture. , Workability is improved.

In the carrier resin composition (B2), the weight average molecular weight of the polycarbonate is not particularly limited and may be, for example, 1,000 or more, but when used in combination with an acrylic plasticizer described later, the phase with the polycarbonate From the viewpoint of improving the solubility, it is preferably 180,000 or more. When the weight average molecular weight of polystyrene is less than 180,000, the compatibility with polycarbonate is good even if it is not used in combination with an acrylic plasticizer described later, as described in the carrier resin composition (B1). From the viewpoint of versatility, the weight average molecular weight of polycarbonate is preferably 450,000 or less, more preferably 400,000 or less, still more preferably 350,000 or less.

[Acrylic plasticizer]
Acrylic plasticizers have a weight average molecular weight of 1,000 or more and 20,000 or less. As a result, when used in combination with polystyrene, especially polystyrene with a weight average molecular weight of 180,000 or more, a carrier resin having a shear viscosity at 130 ° C. of 1.0 × 10 ² Pa · s or more and 1.0 × 10 ⁶ Pa · s or less. The composition (B2) can be easily obtained. The weight average molecular weight of the acrylic plasticizer is preferably 1,000 or more and 18,000 or less, more preferably 1,000 or more and 15,000 or less, and 1,000 or more and 13,000 or less. Is even more preferable.

The acrylic plasticizer preferably has a viscosity at 25 ° C. of 300 mPa · s or more and 100,000 mPa · s or less, more preferably 350 mPa · s or more and 90,000 mPa · s or less, and 400 mPa · s or more and 80, It is more preferably 000 mPa · s or less. When the viscosity of the acrylic plasticizer at 25 ° C is within the above range, the carrier resin composition (B2) having a shear viscosity at 130 ° C of 1.0 × 10 ² Pa · s or more and 1.0 × 10 ⁶ Pa · s or less. ) Is easy to obtain. The acrylic plasticizer is preferably liquid at room temperature (20 ± 5 ° C.). The viscosity of the acrylic plasticizer at 25 ° C. can be measured using an E-type viscometer according to JIS Z 8803-1991.

As the acrylic plasticizer, those generally known as acrylic plasticizers can be used, and it is preferable to use a non-functional acrylic plasticizer. Examples of the acrylic plasticizer include (meth) acrylic acid ester polymers, (meth) acrylic acid ester-aromatic vinyl monomer copolymers, and the like, and (meth) acrylic acid ester polymers are preferable.

The (meth) acrylic acid ester is not particularly limited, but for example, alkyl acrylates having an alkyl group having 10 or less carbon atoms such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; Examples thereof include alkyl methacrylates having an alkyl group having 10 or less carbon atoms, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. These may be used individually by 1 type and may be used in combination of 2 or more type. Above all, it is preferable that it is at least one selected from the group consisting of methyl methacrylate, butyl methacrylate, ethyl acrylate and butyl acrylate.

The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene.

The (meth) acrylic acid ester polymer is a homopolymer of an acrylic acid alkyl ester, a homopolymer of a methacrylic acid alkyl ester, a copolymer of acrylic acid alkyl esters, a copolymer of methacrylic acid alkyl esters, and acrylic. Includes copolymers of acid alkyl esters and methacrylic acid alkyl esters.

The acrylic plasticizer is not particularly limited, but specifically, the product names "UP-1000", "UP-1010", "UP-1020", "UP-1021" and "UP-1021" manufactured by Toagosei Co., Ltd. A commercially available non-functional group type acrylic plasticizer such as "-1061" can be used.

<< Carrier resin composition (B3) >>
The carrier resin composition (B3) contains an acrylic resin having a weight average molecular weight of 8,000 or more and 350,000 or less and the acrylic plasticizer.

The acrylic resin has a weight average molecular weight of preferably 10,000 or more and 330,000 or less, more preferably 10,000 or more and 300,000 or less, and further preferably 10,000 or more and 280,000 or less. Yes, even more preferably 14,000 or more and 330,000 or less, even more preferably 14,000 or more and 300,000 or less, even more preferably 14,000 or more and 280,000 or less, even more preferably. Is 16,000 or more and 330,000 or less, more preferably 16,000 or more and 300,000 or less, even more preferably 16,000 or more and 280,000 or less, and even more preferably 19,000 or more. It is 330,000 or less, more preferably 19,000 or more and 300,000 or less, and even more preferably 19,000 or more and 280,000 or less. The acrylic resin is preferably solid at room temperature (20 ± 5 ° C.) from the viewpoint of handleability.

The acrylic resin includes acrylic resin particles (a) having an average particle diameter of 50 μm or more and 500 μm or less, and acrylic having an average particle diameter of 0.05 μm or more and 0.5 μm or less covering the acrylic resin particles (a). It is more preferable that the acrylic resin contains the based resin particles (b).

The acrylic resin particles (a) may have an average particle diameter of 50 μm or more and 500 μm or less, but preferably 75 μm or more and 300 μm or less, and more preferably 100 μm or more and 250 μm or less. The acrylic resin particles (a) having the above-mentioned average particle diameter can be obtained by a suspension polymerization method. When the average particle size of the acrylic resin particles (a) is 50 μm or more, the filterability is good, and when the average particle size is 500 μm or less, the particulate compound is uniformly mixed with the acrylic resin. be able to. The average particle size of the acrylic resin particles (a) is measured using Microtrack MT3300 manufactured by Microtrack Bell Co., Ltd.

In the acrylic resin, when the acrylic resin particles (b) coat the acrylic resin particles (a), the entire surface of the acrylic resin particles (a) may be coated with the acrylic resin particles (b). , The surface of the acrylic resin particles (a) may be partially coated with the acrylic resin particles (b). The surface area of the acrylic resin particles (a) is preferably 50% or more coated with the acrylic resin particles (b), and more preferably 60% or more. When the surface area to be coated is 50% or more, the powder characteristics of the acrylic resin become good.

By coating the acrylic resin particles (a) with the acrylic resin particles (b), the average particle size of the acrylic resin particles (a) is preferably 3% or more and 50% or less larger than that before coating. If the change of the acrylic resin particles (a) is smaller than 3%, the acrylic resin particles (a) remain in the system, and as a result, the filterability tends to be difficult to improve. That is, the average particle size of the acrylic resin is preferably 3% or more and 50% or less larger than the average particle size of the acrylic resin particles (a). The average particle size of the acrylic resin is measured using Microtrac MT3300 manufactured by Microtrac Bell Co., Ltd.

The acrylic resin particles (a) can be copolymerized with 30% by weight or more and 100% by weight or less of the (meth) acrylic acid ester from the viewpoint of easily controlling the dust associated with the polymer obtained by suspension polymerization. The vinyl monomer is preferably composed of 0% by weight or more and 70% by weight or less. More preferably, the (meth) acrylic acid ester is composed of 70% by weight or more and 100% by weight or less, and 0% by weight or more and 30% by weight or less of a vinyl monomer copolymerizable therewith. When the content of the constituent unit derived from the (meth) acrylic acid ester in the acrylic resin particles (a) is 30% by weight or more, the compatibility with the acrylic resin particles (b) is good and the molding process is good. Become. In the present invention, the "(meth) acrylic acid" may be methacrylic acid or acrylic acid.

The (meth) acrylic acid ester is not particularly limited, and is, for example, alkyl acrylates having an alkyl group having 10 or less carbon atoms such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, and alkyl acrylates. Examples thereof include alkyl methacrylates having an alkyl group having 10 or less carbon atoms, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. These may be used alone or in combination of two or more. Among these, one selected from the group consisting of methyl methacrylate, butyl methacrylate, ethyl acrylate and butyl acrylate from the viewpoint of obtaining a molded product of good quality in combination with the acrylic resin particles (b). The above is preferable.

The vinyl monomer copolymerizable with the (meth) acrylic acid ester is not particularly limited, and is, for example, an aromatic vinyl monomer such as styrene, α-methylstyrene, monochlorostyrene, dichlorostyrene; acrylic acid, methacrylic acid, etc. Vinyl carboxylic acid monomer; Vinyl cyanide monomer such as acrylonitrile and methacrylic acid; Vinyl halide monomer such as vinyl chloride, vinyl bromide and chloroprene; Alkens such as vinyl acetate, ethylene, propylene, butylene, butadiene and isobutylene; Alkens halides; polyfunctional monomers such as allyl methacrylate, diallyl phthalate, triallyl cyanurate, monoethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, divinylbenzene, and glycidyl methacrylate. And so on. These may be used alone or in combination of two or more. Among these, styrene, α-methylstyrene, acrylic acid, methacrylic acid, acrylonitrile, vinyl acetate, allyl methacrylate and methacrylic from the viewpoint of obtaining a molded product of good quality in combination with the acrylic resin particles (b). One or more selected from the group consisting of glycidyl acid acid is preferable.

The acrylic resin particles (a) may be single or mixed polymer particles of a polymer obtained by suspension polymerization of one or more of the above-mentioned monomers, and in some cases copolymerized or graft-polymerized. Can be done.

As the dispersion stabilizer in suspension polymerization, for example, an ordinary inorganic dispersant or an organic dispersant can be used. Examples of the inorganic dispersant include magnesium carbonate, tricalcium phosphate and the like. Examples of the organic dispersant include starch, gelatin, acrylamide, partially saponified polyvinyl alcohol (PVA), partially saponified polymethyl methacrylate, polyacrylic acid, salt of polyacrylic acid, cellulose, methyl cellulose, hydroxymethyl cellulose, and hydroxy. Natural polymer dispersants and synthetic polymer dispersants such as ethyl cellulose, polyalkylene oxide, polyvinyl pyrrolidone, polyvinyl imidazole, and sulfonated polystyrene, and low molecular weight dispersants such as alkylbenzene sulfonates and fatty acid salts (also referred to as emulsifiers). .) Etc. can be mentioned.

Examples of the polymerization initiator in suspension polymerization include peroxides such as benzoyl peroxide and lauroyl peroxide, and azo compounds such as azobisisobutyronitrile.

Further, a chain transfer agent may be used for adjusting the molecular weight. As the chain transfer agent, those listed in the description of the heat-expandable microcapsules can be used.

The amount of the dispersion stabilizer, the polymerization initiator and the chain transfer agent added may be appropriately set according to the physical properties of the monomer to be used and the target suspended polymer particles (acrylic resin particles (a)). it can.

The method for producing the suspended polymer particles is not particularly limited, and any generally usable method can be used. For example, a method in which a monomer or a monomer mixture is suspended in water and the polymerization reaction is carried out as it is, or a part of the monomer or the monomer mixture is suspended in water to start the polymerization reaction and the polymerization reaction is carried out. A method of carrying out the polymerization reaction by dividing the aqueous suspension of the remaining monomer or monomer mixture into one or several stages or continuously adding it to the polymerization reaction tank as the process progresses. Alternatively, a part of the monomer mixture is suspended in water to start the polymerization reaction, and as the polymerization reaction progresses, the remaining monomer or the monomer mixture is divided into one stage or several stages, or continuously. Examples thereof include a method of carrying out a polymerization reaction by adding it to a polymerization reaction tank.

The method of adding the polymerization initiator and the chain transfer agent is not particularly limited, but after dissolving both the polymerization initiator and the chain transfer agent in the monomer, the monomer is suspended in water and the polymerization reaction is carried out as it is. The method to be carried out is preferable. The time required for polymerization varies depending on the type and amount of the polymerization initiator, the polymerization temperature and the like, but is usually 1 to 24 hours. Further, it is also possible to add additives such as a plasticizer, a lubricant, a stabilizer and an ultraviolet absorber to the monomer during suspension polymerization, if necessary.

The acrylic resin particles (b) may have an average particle diameter of 0.05 μm or more and 0.5 μm or less, but preferably 0.06 μm or more and 0.3 μm or less. The acrylic resin particles (b) having the above-mentioned average particle diameter can be obtained by an emulsion polymerization method. When the average particle size of the acrylic resin particles (b) is within the above-mentioned range, the processability at the time of molding the acrylic resin and the impact strength and transparency of the obtained molded product tend to be improved. The average particle size of the acrylic resin particles (b) is measured using Microtrack MT3300 manufactured by Microtrack Bell Co., Ltd.

The acrylic resin particles (b) are preferably composed of 30% by weight or more and 100% by weight or less of the (meth) acrylic acid ester, and 0% by weight or more and 70% by weight or less of the vinyl monomer copolymerizable therewith. (Meta) acrylic acid ester 50% by weight or more and 100% by weight or less, aromatic vinyl monomer 0% by weight or more and 40% by weight or less, vinyl monomer copolymerizable with these 0% by weight or more and 10% by weight or less, and polyfunctional monomer Latex particles (b1) composed of 0% by weight or more and 5% by weight or less, 50 parts by weight or more and 90 parts by weight or less, (meth) acrylic acid ester 10% by weight or more and 100% by weight or less, aromatic vinyl monomer 0% by weight or more. Monomer mixture (b2) containing 90% by weight or less, 0% by weight or more and 25% by weight or less of vinyl cyanide monomer, and 0% by weight or more and 20% by weight or less of vinyl monomer copolymerizable with these, 10 parts by weight or more and 50% by weight. More preferably, the part or less of the polymer particles is polymerized, and the total of the latex particles (b1) and the monomer mixture (b2) is 100 parts by weight.

The (meth) acrylic acid ester constituting the acrylic resin particles (b) is not particularly limited, and for example, the (meth) acrylic acid ester listed at the time of explaining the acrylic resin particles (a) may be appropriately used. it can. The aromatic vinyl monomer, vinyl cyanide monomer, polyfunctional monomer, and other copolymerizable vinyl monomer constituting the acrylic resin particles (b) are not particularly limited, and for example, the acrylic resin particles ( Those listed at the time of the explanation of a) can be appropriately used.

The acrylic resin particles (b) are more preferably methyl methacrylate in an amount of 50% by weight or more and 95% by weight or less, and 5% by weight or more and 50% by weight or less of a methacrylate ester having an alkyl group having 2 or more and 8 or less carbon atoms. 70 parts by weight or more and 95 parts by weight or less of latex particles (b1) obtained by emulsifying and polymerizing a monomer mixture (a) containing 0% by weight or more and 20% by weight or less of a copolymerizable vinyl monomer, and acrylic acid ester and methyl methacrylate. 20% by weight or more and 80% by weight or less of one or more monomers selected from the group consisting of the methacrylic acid esters excluded, 20% by weight or more and 80% by weight or less of methyl methacrylate, and 0 weight of vinyl monomer copolymerizable with these. The monomer mixture (b2) containing% or more and 20% by weight or less is an emulsified polymer particle obtained by graft-polymerizing 5 parts by weight or more and 30 parts by weight or less, and the total of the latex particles (b1) and the monomer mixture (b2) is It is 100 parts by weight. Specifically, methyl methacrylate is 50% by weight or more and 95% by weight or less, 5% by weight or more and 50% by weight or less of a methacrylate ester having an alkyl group having 2 or more and 8 or less carbon atoms, and 0 weight of vinyl monomer copolymerizable with these. A monomer mixture containing% or more and 20% by weight or less (I) of 70 parts by weight or more and 95 parts by weight or less is emulsified and polymerized, and in the presence of the obtained polymer latex, acrylate and methacrylic acid excluding methyl methacrylate One or more monomers selected from the group consisting of esters 20% by weight or more and 80% by weight or less, methyl methacrylate 20% by weight or more and 80% by weight or less, and vinyl monomers copolymerizable with them 0% by weight or more 20 It is an emulsified polymer particle obtained by graft-polymerizing 5 parts by weight or more and 30 parts by weight or less of a monomer mixture (II) containing% by weight or less, and is a monomer mixture (I) and a monomer mixture (II). The total of is preferably 100 parts by weight.

The acrylic resin particles (b) are more preferably methyl methacrylate 40% by weight or more and 99.99% by weight or less, vinyl monomer copolymerizable with them 0% by weight or more and 59.99% by weight or less, and a polyfunctional monomer. Monomer mixture containing 0.01% by weight or more and 10% by weight or less (III) 10 parts by weight or more and 60 parts by weight or less of the first-stage polymer polymerized, and alkyl acrylate 60% by weight or more and 99.9% by weight or less, 40 parts by weight or more and 90 parts by weight or less of a monomer mixture (IV) containing 0% by weight or more and 39.9% by weight or less of a vinyl monomer copolymerizable with these and 0.1% by weight or more and 5% by weight or less of a polyfunctional monomer. The second-stage polymer particles (latex particles (b1)) having a total of 100 parts by weight of the monomer mixture (III) and the monomer mixture (IV) obtained by polymerizing the above and (meth). ) Emulsified polymer particles obtained by polymerizing 11 parts by weight or more and 67 parts by weight or less of a monomer mixture containing 60% by weight or more and 100% by weight or less of an acrylic acid ester and 0% by weight or more and 40% by weight or less of a vinyl monomer copolymerizable therewith. Is. Specifically, methyl methacrylate 40% by weight or more and 99.99% by weight or less, vinyl monomer copolymerizable with these 0% by weight or more and 59.99% by weight or less, and polyfunctional monomer 0.01% by weight or more and 10% by weight. In the presence of the latex of the first-stage polymer obtained by emulsion polymerization of 10 parts by weight or more and 60 parts by weight or less of the monomer mixture (III) containing% or less, the alkyl acrylate is 60% by weight or more and 99.9% by weight. 40 parts by weight or more of the monomer mixture (IV) containing 0% by weight or more and 39.9% by weight or less of the vinyl monomer copolymerizable with these and 0.1% by weight or more and 5% by weight or less of the polyfunctional monomer. The second-stage polymer latex was obtained by emulsion polymerization of parts by weight or less, and the total of the monomer mixture (III) and the monomer mixture (IV) was 100 parts by weight, and the obtained second-stage polymer latex was obtained. In the presence of 100 parts by weight of the solid content (latex particles (b1)), 60% by weight or more and 100% by weight or less of the (meth) acrylic acid ester and 0% by weight or more and 40% by weight or less of the vinyl monomer copolymerizable with these. It is an emulsion polymer particle having a three-layer structure formed by polymerizing 11 parts by weight or more and 67 parts by weight or less of a monomer mixture (b2) containing.

The latex particles (b1) preferably have a glass transition temperature of 0 ° C. or lower, more preferably −30 ° C. or lower. When the glass transition temperature of the latex particles (b1) is 0 ° C. or lower, the impact resistance of the injection foam molded product tends to be improved.

The acrylic resin preferably contains 22 parts by weight or more and 100 parts by weight or less, and 25 parts by weight or more and 100 parts by weight or less of the acrylic resin particles (b) with respect to 100 parts by weight of the acrylic resin particles (a). Is more preferable, and it is further preferable to include 30 parts by weight or more and 100 parts by weight or less. If the amount of the acrylic resin particles (b) is less than 22 parts by weight with respect to 100 parts by weight of the acrylic resin particles (a), the filterability may not be improved. Further, when the acrylic resin particles (b) exceed 100 parts by weight with respect to 100 parts by weight of the acrylic resin particles (a), the water content of the acrylic resin after dehydration may increase.

The acrylic resin is not particularly limited, but can be produced, for example, as follows. First, a suspension containing acrylic resin particles (a) is prepared by suspension polymerization, and an emulsion polymerization latex containing acrylic polymer particles (b) is prepared by emulsion polymerization. Next, the suspension and the emulsion-polymerized latex are mixed. Next, the solid content concentration (total concentration of the acrylic polymer particles (a) and the acrylic polymer particles (b)) in the obtained mixed suspension is adjusted to 25% by weight or more and 35% by weight or less. Next, an aqueous electrolyte solution was added to the mixed suspension in which the solid content was adjusted at a temperature equal to or lower than the Vicat softening temperature of the acrylic polymer particles (b), and the temperature was higher than the Vicat softening temperature of the acrylic polymer particles (b). After heating to a high temperature, the acrylic resin is recovered by solid-liquid separation. By the above-mentioned production method, the surface of the acrylic polymer particles (a) can be uniformly coated with the acrylic polymer particles (b), and the acrylic polymer particles (b) cause deterioration in filterability. It is possible to significantly reduce the residual amount of particles.

The method of mixing the suspension containing the acrylic resin particles (a) obtained by suspension polymerization and the emulsion polymerization latex containing the acrylic polymer particles (b) obtained by emulsion polymerization is carried out under stirring. It is preferable to add the emulsion-polymerized latex to the suspension, or to add the suspension to the emulsion-polymerized latex with stirring.

The solid content ratio of the suspension containing the acrylic resin particles (a) and the emulsion polymerized latex containing the acrylic polymer particles (b) was 100 parts by weight of the acrylic resin particles (a). The particles (b) are preferably 22 parts by weight or more and 100 parts by weight or less, more preferably 25 parts by weight or more and 100 parts by weight or less, and further preferably 30 parts by weight or more and 100 parts by weight or less. When the amount of the acrylic polymer particles (b) is 22 parts by weight or more with respect to 100 parts by weight of the acrylic resin particles (a), the residual acrylic resin particles (b) in the system are reduced, and as a result, filtration is performed. Easy to improve sex. Further, when the amount of the acrylic polymer particles (b) is 100 parts by weight or less with respect to 100 parts by weight of the acrylic resin particles (a), the water content of the obtained acrylic resin after dehydration becomes low.

When the suspension and the emulsion polymerization latex are mixed, the solid content concentration of the suspension and the emulsion polymerization latex is not particularly limited, and the emulsion polymerization latex or the suspension polymerization suspension obtained by a normal polymerization operation can be used. It is most convenient and preferable to use it as it is in terms of production. Usually, the solid content concentration (concentration of acrylic resin particles (a)) of the suspension containing the acrylic resin particles (a) is preferably 25% by weight or more and 55% by weight or less, and 30% by weight or more and 45% by weight. It is more preferably 33% by weight or more and 45% by weight or less, and particularly preferably 35% by weight or more and 40% by weight or less. The solid content concentration of the emulsion polymerized latex containing the acrylic resin particles (b) (concentration of the acrylic resin particles (b)) is preferably 25% by weight or more and 55% by weight or less, and 25% by weight or more and 45% by weight or less. It is more preferably 30% by weight or more and 45% by weight or less, and particularly preferably 30% by weight or more and 40% by weight or less. The temperature at the time of mixing is preferably 5 ° C. or higher, and if it is lower than 5 ° C., the amount of utility used in the subsequent heat treatment operation becomes large, which tends to be unfavorable.

The solid content concentration (concentration of polymer particles) in the mixed suspension when the aqueous electrolyte solution is added is preferably 25% by weight or more and 35% by weight or less, and is 27% by weight or more and 33% by weight or less. Is more preferable. When the concentration of the polymer particles (solid content) in the mixed suspension when the aqueous electrolyte solution is added is 25% by weight or more, the particles in the mixed suspension after the aqueous electrolyte solution is added and heat-treated. The formation of micro-aggregates having a diameter of 50 μm or less is suppressed, the filterability is improved, and the water content of the acrylic resin after dehydration is lowered. Further, when the concentration of the polymer particles in the mixed suspension when the aqueous electrolyte solution is added is 35% by weight or less, the formation of secondary aggregated particles via the acrylic resin particles (b) is suppressed, and the acrylic After dehydration of the based resin, the water content becomes low.

It is preferable to add the aqueous electrolyte solution to the mixed suspension with stirring. By this operation, the acrylic resin particles (b) which are emulsified polymer particles are coagulated (precipitated) on the surface of the acrylic resin particles (a) which are suspension polymer particles, and the surface of the acrylic resin particles (a) is formed. Cover. The addition of the aqueous electrolyte solution needs to be carried out after mixing the suspension polymerization suspension and the emulsion polymerization latex. The reason for this is that when the suspension polymerized suspension and the emulsion polymerized latex are mixed, the presence of an aqueous electrolyte distorts the shape of the acrylic resin produced, which not only increases the water content after dehydration, but also unsolidifies. Acrylic resin particles (b) remain, and the filterability tends to be extremely deteriorated. For example, when an emulsion polymerization latex is added after adding an aqueous electrolyte solution to a suspension of suspension polymerization, the uniformity of coating of the acrylic resin particles (b) on the surface of the acrylic resin particles (a) is lowered, and There arises a problem that the residual amount of the acrylic polymer particles (b), which causes deterioration of filterability, is significantly increased.

As the electrolyte aqueous solution, an aqueous solution of an organic acid, an organic acid salt, an inorganic acid, and an inorganic salt having a property of coagulating and coagulating acrylic resin particles (b) can be appropriately used. Examples of the electrolyte aqueous solution include sodium chloride, potassium chloride, lithium chloride, sodium bromide, potassium bromide, lithium bromide, potassium iodide, sodium iodide, potassium sulfate, sodium sulfate, ammonium sulfate, ammonium chloride, and sodium nitrate. , Potassium nitrate, calcium chloride, ferrous sulfate, magnesium sulfate, zinc sulfate, copper sulfate, barium chloride, ferrous chloride, ferric chloride, magnesium chloride, ferric sulfate, aluminum sulfate, potassium myoban, iron myoban, etc. Aqueous solutions of inorganic salts, aqueous solutions of inorganic acids such as hydrochloric acid, sulfuric acid, nitrate and phosphoric acid, organic acids such as acetic acid and formic acid and their aqueous solutions, and organic acid salts such as sodium acetate, calcium acetate, sodium formate and calcium formate. Examples include an aqueous solution. One of these may be used alone, or two or more thereof may be mixed and used. Among them, the uniformity of coating on the surface of the acrylic resin particles (a) with the acrylic resin particles (b), the drastic reduction of the residual acrylic polymer particles (b) causing deterioration of the filterability, and the wastewater treatment. In terms of ease, aqueous solutions of inorganic salts such as sodium chloride, potassium chloride, sodium sulfate, ammonium chloride, calcium chloride, magnesium chloride, magnesium sulfate, barium chloride, ferrous chloride, aluminum sulfate, potassium myoban, iron myoban, etc. An aqueous solution of inorganic acids such as hydrochloric acid, sulfuric acid and nitrate can be preferably used.

The concentration of the aqueous electrolyte solution is preferably 0.001% by weight or more, more preferably 0.1% by weight or more, still more preferably 1% by weight or more. If the concentration of the aqueous electrolyte solution is less than 0.001% by weight, it is necessary to add a large amount of the aqueous electrolyte solution in order to coagulate the acrylic resin particles (b), and the amount of utility used in the subsequent heat treatment operation is large. There is a risk of becoming.

The addition of the aqueous electrolyte solution needs to be carried out at a temperature equal to or lower than the Vicat softening temperature of the acrylic resin particles (b). If the temperature of the mixed suspension exceeds the Vicat softening temperature of the acrylic resin particles (b) when the electrolyte aqueous solution is added, the shape of the resulting acrylic resin may be distorted and the water content after dehydration may increase, resulting in unsolidification. Acrylic resin particles (b) tend to remain and cause extreme deterioration of filterability, and agglomeration between acrylic resins tends to occur frequently.

When the ratio of emulsion-polymerized latex in the mixed suspension is high, the rate of addition of the aqueous electrolyte solution is extremely high, or the concentration of the aqueous electrolyte solution is extremely high, a significant increase in viscosity is observed when the aqueous electrolyte solution is added. There is. In such a case, an operation may be performed to reduce the viscosity of the system to such an extent that the normal stirring state can be maintained, such as adding water to the system as appropriate. The amount of the aqueous electrolyte solution naturally varies depending on the ratio of the acrylic resin particles (b) in the mixed suspension, but it is sufficient to add an amount or more so that the unsolidified acrylic resin particles (b) do not exist after the heat treatment.

After adding the aqueous electrolyte solution to the mixed suspension, if the aqueous electrolyte solution is an acidic aqueous solution and the mixed suspension after granulation is acidic, neutralize it with an alkali such as sodium hydroxide, or the aqueous electrolyte solution is medium. In the case of a acidic aqueous solution, it is preferable to heat-treat the acrylic polymer particles (b) at a temperature higher than the Vicat softening temperature, for example, 50 to 120 ° C. By the heat treatment, the agglomerates of the acrylic polymer particles (b) coating the surface of the acrylic polymer particles (a) are densified, and the water content of the obtained acrylic resin is lowered. Then, dehydration and drying are carried out according to a conventional method to obtain an acrylic resin.

The masterbatch preferably contains the heat-expandable microcapsules in an amount of 30% by weight or more and 80% by weight or less, more preferably 30% by weight or more and 70% by weight or less, and further preferably 30% by weight or more and 60% by weight or less. ..

From the viewpoint of compatibility with polycarbonate and processability, the masterbatch preferably contains the carrier resin composition in an amount of 20% by weight or more and 70% by weight or less, more preferably 30% by weight or more and 70% by weight or less, and further preferably. Includes 40% by weight or more and 70% by weight or less.

When the masterbatch contains the carrier resin composition (B1), it is concrete from the viewpoints of compatibility with polycarbonate, shear viscosity at 130 ° C., handleability, storage stability, dispersibility in the base resin, and the like. It is preferable that the heat-expandable microcapsules are contained in an amount of 30% by weight or more and 80% by weight or less, the carrier resin composition (B1) is preferably contained in an amount of 20% by weight or more and 70% by weight or less, and the heat-expandable microcapsules are contained in an amount of 30% by weight or more. % To 70% by weight, more preferably 30% by weight or more and 70% by weight or less of the carrier resin composition (B1), and 30% by weight or more and 60% by weight or less of the heat-expandable microcapsules, the carrier resin composition ( It is more preferable to contain B1) in an amount of 40% by weight or more and 70% by weight or less.

When the masterbatch contains the carrier resin composition (B2), preferably, the heat-expandable microcapsules are 30% by weight or more and 80% by weight or less, the polystyrene is 15% by weight or more and 40% by weight or less, and the acrylic plasticizer. The agent is contained in an amount of 5% by weight or more and 30% by weight or less. When the blending amount of the acrylic plasticizer is 5% by weight or more, the low shearing effect is likely to be exhibited at the time of producing the master batch, and the capsule can be prevented from breaking. Further, when the blending amount of the acrylic plasticizer is 30% by weight or less, the increase in the amount of thermal decomposition of the plasticizer with respect to the temperature at the time of foam molding is suppressed, and the appearance is prevented from being adversely affected. .. More preferably, the masterbatch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 45% by weight or less of the polystyrene, and 8% by weight or more and 25% by weight of the acrylic plasticizer. Including the following. More preferably, the masterbatch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 50% by weight or less of the polystyrene, and 8% by weight or more and 20% by weight or less of the acrylic plasticizer. Including. Particularly preferably, the master batch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 55% by weight or less of the polystyrene, and 8% by weight or more and 15% by weight or less of the acrylic plastic agent. Including.

When the masterbatch contains the carrier resin composition (B3), preferably, the heat-expandable microcapsules are 30% by weight or more and 80% by weight or less, the acrylic resin is 15% by weight or more and 40% by weight or less, and the acrylic. Contains 5% by weight or more and 30% by weight or less of the plasticizer. When the blending amount of the acrylic plasticizer is 5% by weight or more, the low shearing effect is likely to be exhibited at the time of producing the master batch, and the capsule can be prevented from breaking. Further, when the blending amount of the acrylic plasticizer is 30% by weight or less, the increase in the amount of thermal decomposition of the plasticizer with respect to the temperature at the time of foam molding is suppressed, and the appearance is prevented from being adversely affected. .. More preferably, the masterbatch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 45% by weight or less of the acrylic resin, and 8% by weight or more and 25% by weight of the acrylic plasticizer. Includes less than% by weight. More preferably, the masterbatch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 50% by weight or less of the acrylic resin, and 8% by weight or more and 20% by weight of the acrylic plasticizer. Including% or less. Particularly preferably, the masterbatch contains 30% by weight or more and 80% by weight or less of the heat-expandable microcapsules, 12% by weight or more and 55% by weight or less of the acrylic resin, and 8% by weight or more and 15% by weight of the acrylic plasticizer. Including% or less.

In the polycarbonate-based resin composition, the content of the masterbatch may be appropriately set according to the expansion ratio of the final product, the type of foaming agent, the resin temperature at the time of molding, and the like. The content of the masterbatch in the polycarbonate resin composition is preferably 1% by weight or more and 15% by weight or less, more preferably 2% by weight or more and 15% by weight or less, and particularly preferably 3% by weight or more and 10% by weight or less. By using the masterbatch in this range, it is economically easy to obtain a foamed molded product having a foaming ratio of 1.1 times or more and uniform fine bubbles.

The polycarbonate is a polycarbonate derived from a compound having two phenolic hydroxyl groups (hereinafter referred to as divalent phenol), and is usually obtained by a reaction between divalent phenol and phosgen or divalent phenol and carbonic acid diester. Use resin.

Examples of the divalent phenol include biphenol, methylene bisphenol (bisphenol F), bis (4-hydroxyphenyl) sulfone (bisphenol S), 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) and the like. Of these, bisphenol A is preferable, but is not limited thereto.

From the viewpoint of impact resistance, chemical resistance, molding processability, etc., the polycarbonate preferably has a number average molecular weight of 10,000 or more and 60,000 or less, and more preferably 10,000 or more and 30,000 or less. .. The content of polycarbonate in the polycarbonate resin composition is preferably 30% by weight or more and 99% by weight or less, more preferably 30% by weight or more and 80% by weight or less, and further preferably 30% by weight or more and 70% by weight or less.

The polycarbonate-based resin composition further comprises a polyester-based resin, a polyester-polyether copolymer, an acrylonitrile-butadiene-styrene copolymer, an acrylonitrile-ethylene-propylene-diene-styrene copolymer, and an acrylate-styrene-acrylonitrile. It may contain one or more other thermoplastic resins selected from the group consisting of polymers, acrylonitrile-styrene copolymers, polyarylate resins, polystyrene resins, and polyamide resins.

The polyester-based resin includes amorphous thermoplastic polyester-based resins such as amorphous aliphatic polyester, amorphous semi-aromatic polyester, and amorphous total aromatic polyester, crystalline aliphatic polyester, and crystalline semi-aromatic. Use a crystalline thermoplastic polyester resin such as polyester or crystalline total aromatic polyester, a liquid crystal thermoplastic polyester resin such as liquid crystal aliphatic polyester, liquid crystal semi-aromatic polyester, or liquid crystal total aromatic polyester. Can be done.

Specific examples of the crystalline thermoplastic polyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polybutylene naphthalate, poly1,4-cyclohexylene methylene terephthalate, and polyethylene-1,2. Crystalline of -bis (phenoxy) ethane-4,4'-dicarboxylate, polyethylene isophthalate / terephthalate, polybutylene terephthalate / isophthalate, polybutylene terephthalate / decandicarboxylate, polycyclohexanedimethylene terephthalate / isophthalate, etc. Examples thereof include copolymerized polyester. Of these, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polybutylene naphthalate, poly1,4-cyclohexylene methylene terephthalate and the like are preferably used. The content of the thermoplastic polyester resin in the polycarbonate resin composition is preferably 60% by weight or less, more preferably 50% by weight or less, from the viewpoint of improving the appearance of the injection foam molded product. , 40% by weight or less is more preferable.

The polyester-polyester copolymer preferably contains an aromatic polyester unit and a polyether unit. The polyether unit is represented by, for example, the following general formula (1), general formula (2), general formula (3), general formula (4), general formula (5) and general formula (6). Can be mentioned. Among these, those represented by the following general formula (6) are preferable.

In the general formula (1), -A- is -O-, -S-, -SO-, -SO _2- , -CO-, an alkylene group having 1 to 20 carbon atoms, or an alkylidene having 6 to 20 carbon atoms. It is a group. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are hydrogen atoms, halogen atoms, or monovalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. R ⁹ and R ¹⁰ are divalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. m and n indicate the number of repeating units of the oxyalkylene unit, and m and n are integers of 0 to 70, respectively, and 10 ≦ m + n ≦ 70.

In the general formula (2), R ¹ , R ² , R ³ , and R ⁴ are hydrogen atoms, halogen atoms, or monovalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. R ⁹ and R ¹⁰ are divalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. m and n indicate the number of repeating units of the oxyalkylene unit, and m and n are integers of 0 to 70, respectively, and 10 ≦ m + n ≦ 70.

In the general formula (3), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are hydrogen atoms, halogen atoms, or monovalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. .. R ⁹ and R ¹⁰ are divalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. m and n indicate the number of repeating units of the oxyalkylene unit, and m and n are integers of 0 to 70, respectively, and 10 ≦ m + n ≦ 70.

In the general formula (4), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ are hydrogen atoms, halogen atoms, or monovalents having 1 to 5 carbon atoms, respectively. It is a hydrocarbon group of. R ⁹ and R ¹⁰ are divalent hydrocarbon groups having 1 to 5 carbon atoms, respectively. m and n indicate the number of repeating units of the oxyalkylene unit, and m and n are integers of 0 to 70, respectively, and 10 ≦ m + n ≦ 70.

In the general formula (5), R ⁹ is a divalent hydrocarbon group having 1 to 5 carbon atoms. m indicates the number of repeating units of the oxyalkylene unit, and m is an integer of 2 to 70.

In the general formula (6), m and n indicate the number of repeating units of the oxyalkylene unit, and m and n are integers of 0 to 50, respectively, and 10 ≦ m + n ≦ 50.

The aromatic polyester unit is an alternating polycondensate composed of an aromatic dicarboxylic acid or an aromatic dicarboxylic acid ester and a diol. Examples of the aromatic polyester unit include polyalkylene terephthalate units such as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate; and polyalkylene naphthalate units such as polyethylene naphthalate, polypropylene naphthalate and polybutylene naphthalate. Among these, the polyalkylene terephthalate unit is preferable, and the polyethylene terephthalate unit is more preferable. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and the like. Of these, terephthalic acid is preferable. Examples of the aromatic dicarboxylic acid ester include dialkyl esters of the aromatic dicarboxylic acid. In addition to the aromatic dicarboxylic acid, other aromatic oxycarboxylic acids such as oxybenzoic acid, and aliphatic or alicyclic dicarboxylic acids such as adipic acid, sebatic acid, and cyclohexane 1,4-dicarboxylic acid are used in combination. May be. The diol is, for example, a glycol having 2 or more and 10 or less carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, hexanediol, decanediol, and cyclohexanedimethanol. The solution viscosity of the aromatic polyester is concentrated at 25 ° C. in a phenol / tetrachloroethane = 1/1 (weight ratio) mixed solvent from the viewpoint of impact resistance, chemical resistance and molding processability of the obtained molded product. The logarithmic viscosity (IV value) at 0.5 g / dl is preferably 0.3 or more and 1.0 or less.

The method for producing the polyester-polyether copolymer is not particularly limited, but is (1) a direct transesterification method in which an aromatic dicarboxylic acid, a diol and a polyether are reacted, and (2) an aromatic dicarboxylic acid dialkyl ester and a diol. , And a method of transesterification in which polyethers are reacted, (3) a method of adding a modified polyether during or after transesterification of an aromatic dicarboxylic acid dialkyl ester and a diol to carry out polycondensation, (4) a polymer. Examples thereof include a method in which the aromatic polyester of No. 1 is mixed with polyether and then transesterified under melting and reduced pressure.

The content of the polyester-polyester copolymer in the polycarbonate resin composition is preferably 0 to 60% by weight, preferably 0 to 50% by weight, from the viewpoint of improving the appearance of the injection foam molded product. More preferably, it is more preferably 0 to 40% by weight.

From the viewpoint of improving the appearance and maintaining heat resistance, the acrylonitrile-butadiene-styrene copolymer is preferably contained in an amount of 50% by weight or less based on 100% by weight of the polycarbonate resin composition, and a more preferable range is 40. By weight% or less, a more preferable range is 30% by weight or less.

The content of butadiene in the acrylonitrile-butadiene-styrene copolymer may be 10% by weight or more and 30% by weight or less.

As the acrylonitrile-butadiene-styrene copolymer, a part of styrene in the acrylonitrile-butadiene-styrene copolymer is replaced with α-methylstyrene to improve the heat resistance as compared with the usual acrylonitrile-butadiene-styrene copolymer. Acrylonitrile-butadiene-styrene copolymer modified with phenylmaleimide or the like can also be appropriately used as it has improved heat resistance.

In the polycarbonate resin composition, when the thermoplastic resin molded body 1 is an injection foamed molded product, the master batch is 1 from the viewpoint of effectively suppressing whitening of the surface of the injection foamed molded product and improving the appearance. Weight% or more and 15% by weight or less, 30% by weight or more and 99% by weight or less of the polycarbonate, and polyester resin, polyester-polyether copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-ethylene-propylene-diene- 0 weight of one or more thermoplastic resins selected from the group consisting of styrene copolymers, acrylate-styrene-acrylonitrile copolymers, acrylonitrile-styrene copolymers, polyarylate resins, polystyrene resins, and polyamide resins. It is preferably contained in an amount of% or more and 55% by weight or less.

When the thermoplastic resin molded product 1 is an injection foam molded product, the polycarbonate resin composition may further contain an inorganic compound in order to improve the flexural rigidity and dimensional stability of the injection foam molded product. The inorganic compound is selected from the group consisting of mica, talc, montmorillonite, sericite, kaolin, glass flakes, plate-like alumina, synthetic hydrotalcite, wallastnite, hollow glass balloon, carbon fiber, aramid fiber, and whiskers. One or more is preferable, and mica, talc, montmorillonite, cericite, kaolin, glass flakes, hollow glass beads, and carbon fibers are more preferable, and impact resistance, from the viewpoint of bending rigidity improving effect and dispersibility in polycarbonate resin. Mica, talc, glass flakes and wallastnite are more preferred from the standpoint of balancing fluidity and product appearance.

The content of the inorganic compound is preferably 5% by weight or more and 45% by weight or less, preferably 5% by weight or more and 35% by weight or less in the polycarbonate resin composition from the viewpoint of impact resistance, heat resistance, rigidity, moldability and the like. Is more preferable, and 5% by weight or more and 25% by weight or less is further preferable.

When the thermoplastic resin molded product 1 is an injection foam molded product, the polycarbonate resin composition may further contain an impact resistance modifier in order to further improve the impact resistance of the injection foam molded product. As the impact resistance improving agent, one or more selected from the group consisting of a multi-stage graft polymer, a polyolefin-based polymer, an olefin-unsaturated carboxylic acid ester copolymer, and a thermoplastic polyester-based elastomer is preferable.

The multi-stage graft polymer is a rubber-like polymer obtained by graft-polymerizing a vinyl-based monomer. The rubber-like polymer preferably has a glass transition temperature of 0 ° C. or lower, more preferably −40 ° C. or lower. Specific examples of such rubber-like polymers include diene rubbers such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylic acid ester copolymer, and butadiene-acrylonitrile copolymer, butyl polyacrylate, and poly. Acrylic rubber such as 2-ethylhexyl acrylate, dimethylsiloxane-butyl acrylate rubber, silicon-based / butyl acrylate composite rubber, olefin-based rubber such as ethylene-propylene copolymer, ethylene-propylene-diene copolymer, polydimethyl Examples thereof include siloxane-based rubbers and dimethylsiloxane-diphenylsiloxane copolymer-based rubbers. Examples of the butadiene-acrylic acid ester copolymer include a butadiene-butyl acrylate copolymer and a butadiene-acrylic acid diethylhexyl copolymer. From the viewpoint of impact resistance, polybutadiene, butadiene-styrene copolymer, and butadiene-butyl acrylate copolymer are preferably used. Among the butadiene-butyl acrylate copolymers, a copolymer of 50 to 70% by weight of butyl acrylate and 30 to 50% by weight of butadiene is preferable from the viewpoint of weather resistance and impact resistance. The average particle size of the rubber-like polymer is not particularly limited, but it is preferably in the range of 0.05 μm or more and 2.00 μm or less, and more preferably 0.1 μm or more and 0.4 μm or less. The gel content is also not particularly limited, but those in the range of 10% by weight or more and 99% by weight or less, and further 80% by weight or more and 96% by weight or less are preferably used.

Examples of the vinyl-based monomer used in the production of the multi-stage graft polymer include aromatic vinyl monomer, vinyl cyanide monomer, (meth) acrylic acid ester and the like. One of these may be used alone, or two or more thereof may be used in combination. As the aromatic vinyl monomer, the cyanide vinyl monomer, and the (meth) acrylic acid ester, those listed at the time of the description of the acrylic resin particles (a) can be appropriately used.

Specifically, the multistage graft polymer is 10 weights of one or more rubber-like polymers selected from the group consisting of polybutadiene, butadiene-styrene copolymer, butadiene-acrylic acid ester copolymer, and polyorganosiloxane. % To 90% by weight, and one or more vinyl-based monomers selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth) acrylic acid ester compounds in the presence of the rubbery polymer. It is preferable that the graft component is composed of 10% by weight or more and 90% by weight or less of the graft component composed of the polymer obtained by polymerizing. It is particularly preferable to use a multi-stage graft polymer produced by using an organophosphorus emulsifier.

When a core / shell graft polymer is prepared as the multi-stage graft polymer, when the total amount of the rubber-like polymer and the vinyl-based monomer is 100% by weight, the rubber-like polymer is 10% by weight or more and 90% by weight or less, vinyl. It is preferable that the based monomer is 10% by weight or more and 90% by weight or less, the rubber-like polymer is 30% by weight or more and 85% by weight or less, and the vinyl-based monomer is 15% by weight or more and 70% by weight or less. If the proportion of the rubber-like polymer is less than 10% by weight, the impact resistance tends to decrease, while if it exceeds 90% by weight, the heat resistance tends to decrease.

The amount of the impact-resistant modifier is preferably 0% by weight or more and 20% by weight or less, preferably 0% by weight, in the polycarbonate-based resin composition from the viewpoint of impact resistance, heat resistance, rigidity, moldability, and the like. It is more preferably 15% by weight or more, and further preferably 0% by weight or more and 10% by weight or less.

Further, the polycarbonate-based resin composition is further added with a flame retardant, a UV resistant agent, a stabilizer, a mold release agent, a pigment, a softening agent, a plasticizer, a surfactant, etc., depending on the use of the thermoplastic resin molded product 1. It may contain an agent.

The reinforcing rib 3 may be integrally molded with the same material as the main body 2, or the reinforcing rib 3 prepared in advance as a separate member may be integrated with the main body 2 by heat fusion or the like, but productivity From the viewpoint of the reinforcing effect, the reinforcing rib 3 is preferably integrally molded with the main body 2. Specifically, the thermoplastic resin molded body 1 can be manufactured by integrally molding the main body 2 and the reinforcing rib 3 by injection foam molding, foam extrusion molding, or the like. From the viewpoint that a molded product having a complicated shape can be easily obtained, it can be produced by injection foam molding.

By injection foaming the polycarbonate resin composition, whitening is suppressed, and it is easy to obtain a thermoplastic resin molded product 1 having a good appearance. Specifically, the injection foam molded product can be produced by a method of foaming the polycarbonate resin composition in a mold. There are various methods of foaming in the mold, but among them, it is composed of a fixed mold (also called a cavity) and a movable mold (also called a core) that can move forward and backward at an arbitrary position. The so-called core back method (Moving Cavity method) is preferable, in which the resin composition is injected to the initial filling thickness using a mold, and then the movable mold is retracted and foamed. According to the core back method, a skin layer (non-foaming layer) is formed on the surface of the main body to smooth out irregularities on the order of several μm to several tens of μm on the outside, and the foamed layer inside becomes uniform fine bubbles. It is preferable because it is easy to obtain an injection-foamed molded product having excellent lightness.

In the mold, either the fixed mold or the movable mold is provided with engraving or the like for forming the reinforcing rib 3 having the above-mentioned shape and dimensions.

In the core back method, the movable retreat may be performed in one step, may be performed in multiple steps of two or more steps, and the retreat speed may be adjusted as appropriate. In the core back method, the molding conditions are not particularly limited, but for example, the resin temperature is 240 ° C. or higher and 280 ° C. or lower, the mold temperature is 60 ° C. or higher and 90 ° C. or lower, the molding cycle is 1 second or longer and 60 seconds or lower, and the injection speed is 10 mm / Conditions such as seconds or more and 400 mm / sec or less, injection pressure of 10 MPa or more and 200 MPa or less, back pressure of 5 MPa or more and 40 MPa or less, and screw rotation speed of 10 rpm or more and 200 rpm or less may be used.

The specific gravity of the thermoplastic resin molded product 1 is preferably 0.3 g / cm ³ or more and 1.2 g / cm ³ or less from the viewpoint of weight reduction and impact strength. If the specific gravity of the thermoplastic resin molded product 1 is less than 0.3 g / cm ³ , coarse bubbles exceeding 1.5 mm tend to increase and the impact strength tends to decrease, and if it exceeds 1.2 g / cm ³ , the weight is reduced. Hard to achieve. The specific gravity conforms to JIS K 7112: 1999 and can be calculated by the underwater substitution method.

In the thermoplastic resin molded product 1, the foaming ratio of the main body 2 is preferably 1.1 times or more and 3.0 times or less, more preferably 1.1 times or more and 2.5 times or less, from the viewpoint of weight reduction and impact strength. It is preferable, and more preferably 1.1 times or more and 2.0 times or less. If the foaming ratio is less than 1.1 times, it tends to be difficult to obtain light weight, and if it exceeds 3.0 times, the surface impact strength tends to decrease significantly. In the present specification, the foaming ratio is a value obtained by dividing the thickness of the injection foam molded product (cavity clearance t _f after core back) by the initial cavity clearance t ₀ . The reinforcing rib 3 may or may not be foamed.

The surface impact strength of the thermoplastic resin molded product 1 is calculated by 50% fracture energy by conducting a DuPont impact test (measured according to ASTM D 2794) in an environment of -30 ° C in the built-in chamber. Can be evaluated. The impact is applied to the side where the reinforcing ribs are not formed (design surface side), directly under the reinforcing ribs provided on the non-design surface side, or to the corresponding locations between the reinforcing ribs and the reinforcing ribs. The value of the surface impact strength (50% fracture energy) directly under the reinforcing rib is preferably 1.9 J or more, more preferably 2.0 J or more, and further preferably 2.1 J or more. .. Further, the value of the surface impact strength (50% fracture energy) directly under the reinforcing rib is preferably 50 J or less. Further, the value of the surface impact strength (50% fracture energy) between the reinforcing ribs is preferably 2.0 J or more, and more preferably 2.1 J or more. Further, the value of the surface impact strength (50% fracture energy) between the reinforcing ribs is preferably 50 J or less.

The thermoplastic resin molded body 1 includes exterior parts (housing, etc.) and internal mechanism parts of OA equipment such as copiers, personal computers, and faclimill; exterior parts and internal mechanism parts of home appliances such as refrigerators, air conditioners, and vacuum cleaners; automobiles. It can be suitably used as an interior part or an exterior part (including an outer panel part) of a vehicle such as the above. In particular, it can be suitably used as an exterior part (including an outer panel part) of a vehicle such as an automobile. Examples of vehicle exterior parts and outer panel parts include automobile fenders, door panels, back door panels, garnishes, pillars, spoilers, and the like.

The present invention is not particularly limited, but includes, for example, the following aspects.
[1] In a main body portion made of a thermoplastic resin foam and a thermoplastic resin molded body provided with reinforcing ribs formed on the back surface side of the main body portion.
When observing the cross section of the reinforcing rib, the root portion of the reinforcing rib bulges outward, so that the joint portion between the reinforcing rib and the main body portion has a curved shape, and the reinforcing rib is used for reinforcement. The tip of the rib has a radius of curvature at both corners or is arcuate.
The thickness T1 of the main body is 1.8 mm or more and 6.0 mm or less.
The radius of curvature Ra of the joint is 0.05 mm or more and 2.2 mm or less.
A thermoplastic resin molded product, wherein the ratio T3 / T1 of the thickness T1 of the main body to the maximum thickness T3 of the reinforcing rib is larger than 0.25 and 0.75 or less.
[2] The heat according to [1], wherein the tip portion of the reinforcing rib has a shape having a radius of curvature Rb at both corners, and the radius of curvature Rb of the corner is 0.05 mm or more and 2.2 mm or less. Plastic resin molded body.
[3] The tip of the reinforcing rib has a shape of a true arc having a radius of curvature Rc of 0.05 mm or more and 2.2 mm or less, or an elliptical arc having a radius of curvature Rd of 0.05 mm or more and 9.5 mm or less. The thermoplastic resin molded product according to [1].
[4] The thermoplastic resin according to any one of [1] to [3], wherein the average thickness T2 of the portion of the reinforcing rib excluding the tip portion and the root portion is 0.2 mm or more and 4.3 mm or less. Molded body.
[5] The thermoplastic resin molded product according to any one of [1] to [4], wherein the height H of the reinforcing rib is 2 mm or more and 15 mm or less.
[6] The heat according to any one of [1] to [5], wherein the ratio H / T2 of the height H of the reinforcing rib to the average thickness T2 of the reinforcing rib is 0.4 or more and 75 or less. Plastic resin molded body.
[7] The reinforcing ribs are arranged so that the longitudinal direction is along the longitudinal direction of the thermoplastic resin molded body, and the interval in the width direction between the adjacent reinforcing ribs is 3 mm or more and 20 mm or less. 1] The thermoplastic resin molded article according to any one of [6].
[8] The thermoplastic resin molded product is an injection foam molded product, and the specific gravity of the thermoplastic resin molded product is 0.3 g / cm ³ or more and 1.2 g / cm ³ or less, or the foaming ratio of the main body is 1. The thermoplastic resin molded product according to any one of [1] to [7], which is 1-fold or more and 3.0-fold or less.
[9] Any of [1] to [8], wherein the length of the thermoplastic resin molded product is 200 mm or more and 3000 mm or less, and / or the width of the thermoplastic resin molded product is 50 mm or more and 3000 mm or less. The thermoplastic resin molded article according to.
[10] The thermoplastic according to any one of [1] to [9], wherein the value of the surface impact strength measured by the following method for measuring the surface impact strength is 1.9 J or more in the thermoplastic resin molded product. Resin molded body.
(Measurement method of surface impact strength)
The inside of the built-in chamber is set to an environment of −30 ° C., a DuPont impact test (measured according to ASTM D 2794) is performed, and 50% fracture energy is calculated to obtain the surface impact strength. The impact is applied to a portion directly below the reinforcing rib provided on the non-design surface side on the side where the reinforcing rib is not formed (design surface side).
[11] The thermoplastic resin molded product according to any one of [1] to [10], wherein the thermoplastic resin molded product contains polycarbonate and / or ABS resin.
[12] The thermoplastic resin molded product according to any one of [1] to [11], wherein the thermoplastic resin molded product is a foam molded product of a thermoplastic resin composition containing a heat-expandable microcapsule.
[13] The thermoplastic resin molded product is one or more selected from the group consisting of automobile parts, exterior parts of OA equipment, internal mechanical parts of OA equipment, exterior parts of home appliances, and internal mechanical parts of home appliances. The thermoplastic resin molded product according to any one of [1] to [12].
[14] The thermoplastic resin molded product according to [13], wherein the automobile parts are one or more selected from the group consisting of exterior parts and outer panel parts.
[15] The method for producing a thermoplastic resin molded product according to any one of [1] to [14].
A method for manufacturing a thermoplastic resin molded body, which comprises a step of integrally molding the main body and reinforcing ribs by injection molding to obtain a thermoplastic resin molded body.

Hereinafter, the present invention will be described in more detail based on examples. The present invention is not limited to the following examples. In the following, unless otherwise specified, "part" means "part by weight" and "%" means "% by weight".

Various measurement methods and evaluation methods are shown below.

(1) Glass transition temperature Acrylic resin particles (a) (suspended polymer particles) are subjected to a temperature rise condition of 5 ° C./min using a differential scanning calorimeter (DSC220C manufactured by Seiko Denshi Kogyo Co., Ltd.). The glass transition temperature was measured.
(2) Vicat softening temperature The measurement of the Vicat softening temperature of the acrylic resin particles (b) (emulsified polymer particles) was carried out based on the JIS K7206 A method. The test piece was prepared by recovering the emulsified polymer obtained by emulsion polymerization by coagulation, heat treatment, and drying, pelletizing it with an extrusion molding machine, and then sheeting it with a press molding machine.
(3) Average Particle Size The average particle size of the acrylic resin particles (a), the acrylic resin particles (b) and the acrylic resin was measured with Microtrac MT-3300 manufactured by Microtrac Bell Co., Ltd. The average particle size (when not expanded) of the heat-expandable microcapsules was measured by a particle size distribution measuring device SALD-3000J manufactured by Shimadzu Corporation.
(4) Weight average molecular weight The weight average molecular weight of the resin was measured by GPC (gel permeation chromatography). Specifically, the measurement was performed using a system: HLC-8220 manufactured by Tosoh, a column: TSKgel SuperHZM-H (x2) manufactured by Tosoh, and a solvent: THF, and determined in terms of polystyrene.
(5) Compatibility with Polycarbonate (PC) Differential scanning calorimetry (DSC) of the carrier resin composition and the mixture of polycarbonate was performed, and the presence or absence of compatibility with PC was determined based on the following criteria.
Compatibility: One peak of glass transition temperature in DSC Non-compatible: Two peaks of glass transition temperature in DSC (6) Shear viscosity The shear viscosity of the carrier resin composition at 80 ° C. , Shimadzu's flow tester "Model CFT-500C" was used for measurement. Specifically, the measurement start temperature is set to 50 ° C., and a constant load of 30 kgf is applied to the carrier resin composition to flow the carrier resin composition in a capillary having a diameter of 1.0 mm and a length of 10 mm, and the temperature is raised at 10 ° C./min to measure the temperature. The shear viscosity was measured when the temperature reached 80 ° C.
(7) Viscosity The viscosity of the plasticizer at 25 ° C. was measured using an E-type viscometer according to JIS Z 8803-1991.
(8) Maximum expansion temperature "TMA measurement" was performed using a TMA-7 type manufactured by Birkin Elmer. When about 0.25 mg of the sample is placed in a container, the temperature is raised at a temperature rising rate of 5 ° C./min, the displacement of the height is continuously measured, and the displacement of the height of the sample in the container is maximized. The temperature of was taken as the maximum expansion temperature.
(9) Masterbatch workability The cross section of the masterbatch pellet was observed with a scanning electron microscope (SEM, manufactured by JEOL Ltd., model "JSM-6060LA"), and based on the state of the thermally expandable microcapsules, The workability of the masterbatch was evaluated.
Good: No expansion of the heat-expandable microcapsule Defective: With expansion of the heat-expandable microcapsule (10) Expansion ratio of the injection foam molded product The thickness of the flat plate-shaped injection foam molded product (cavity clearance t _f after core back) It was calculated by dividing by the cavity clearance t ₀ in the molded state of the mold of the relevant part.
(11) Sink marks on the design surface side of the injection foam molded product The design surface side of the injection foam molded product was visually observed, and the presence or absence of sink marks at the locations corresponding to the reinforcing rib installation locations on the non-design surface side was evaluated.
(12) Surface Impact Strength of Injection Foam Mold A test piece was cut out from the injection foam mold so as to have a size of 55 mm x 55 mm including the engraved portion as shown in FIG. 7, and the inside of the build-in chamber was placed in an environment of -30 ° C. 50% fracture energy was calculated by performing an impact test (measured according to ASTM D 2794). Although the impact was applied from the design surface side, it was applied to a portion directly under the rib provided on the non-design surface side or between the ribs. Schematic diagrams of the test pieces in Example 1 and Comparative Example 1 are shown in FIGS. 7 (a) and 7 (b). Schematic diagrams of the test pieces in Example 2 are shown in FIGS. 7 (a) and 7 (c).

<Production example 1 of acrylic resin>
<Preparation of acrylic resin particles (a)>
220 parts of deionized water and 15 parts of a 3% PVA aqueous solution (GH-20: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) were charged into a reactor with a stirrer, and the inside of the reactor was replaced with nitrogen. A monomer mixture of 25 parts of butyl acrylate and 75 parts of methyl methacrylate in which 0.5 parts of lauroyl peroxide, 0.5 parts of benzoyl peroxide and 0.5 part of 2-ethylhexyl thioglycolic acid were dissolved was charged therein. The rotation speed of the stirrer was adjusted so that the dispersed particle size of the monomer was about 250 μm. Then, the temperature was gradually raised to 60 ° C. for 2 hours, 70 ° C. for 2 hours, 80 ° C. for 2 hours, and 90 ° C. for 1 hour to complete the polymerization, and the acrylic resin particles (a) (polymer solid content). A suspension of acrylic resin particles (a) having a concentration of 30%, a glass transition temperature of 72 ° C., and an average particle diameter of 150 μm was prepared.

<Preparation of acrylic resin particles (b)>
220 parts of deionized water, 0.3 part of boric acid, 0.03 part of sodium carbonate, 0.09 part of sodium N-lauroyl sarcosate, 0.09 part of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate in a stirrer addition reactor 0.006 part and 0.002 part of ferrous sulfate heptahydrate were charged, and after nitrogen substitution, the temperature was raised to 80 ° C., to which 25 parts of methyl methacrylate, 0.1 part of allyl methacrylate, and t-butyl were added. Twenty-five percent of the monomer mixture consisting of 0.1 part of hydroperoxide was charged in a batch and polymerized for 45 minutes. Subsequently, the remaining 75% of this mixture was continuously added over an hour. After the addition was completed, the mixture was kept at the same temperature for 2 hours to complete the polymerization. In the meantime, 0.2 parts by weight of sodium N-lauroylsarcosine was added. The average particle size of the polymer particles in the latex of the obtained innermost crosslinked methacrylic polymer was 1600 Å (determined using light scattering with a wavelength of 546 nm), and the polymerization conversion rate (polymer production amount / monomer). The amount charged x 100) was 98%. Subsequently, the latex of the obtained innermost crosslinked methacrylic polymer was kept at 80 ° C. in a nitrogen stream, 0.1 part by weight of potassium persulfate was added, and then 41 parts by weight of n-butyl acrylate and 9 parts by weight of styrene were added. A mixture of 1 part by weight of allyl methacrylate and 1 part by weight of allyl methacrylate was continuously added over 5 hours. During this period, 0.1 part by weight of potassium oleate was added in 3 portions. After the addition of the monomer mixed solution was completed, 0.05 parts by weight of potassium persulfate was further added to complete the polymerization, and the mixture was retained for 2 hours. In the obtained emulsion-polymerized latex, the average particle size of the latex particles (b1) was 2300 Å, and the polymerization conversion rate was 99%. Subsequently, the latex of the latex particles (b1) was kept at 80 ° C., 0.02 parts by weight of potassium persulfate was added, and then 24 parts by weight of methyl methacrylate, 1 part by weight of n-butyl acrylate, and 0 parts by weight of t-dodecyl mercaptan. . 1 part by weight of the mixed solution was continuously added over 1 hour. After the addition of the monomer mixture was completed, the mixture was held for 1 hour to obtain a latex of an emulsion polymerization graft copolymer (acrylic resin particles (b)) having a multilayer structure, an average particle size of 0.25 μm, and a Vicat softening temperature of 90 ° C. It was.

<Making acrylic resin>
96 parts of the latex of the obtained acrylic resin particles (b) (solid content, that is, 30 parts of the acrylic resin particles (b)) and 332 parts of the suspension of the acrylic resin particles (a) (solid content, that is, the acrylic resin). The particles (a) (100 parts) are mixed under stirring, and the obtained mixed suspension (solid content, that is, the total concentration of the acrylic resin particles (a) and the acrylic resin particles (b) is 30%) is brought to 60 ° C. After the adjustment, 50 parts of a 1.0% aqueous solution of calcium chloride was added dropwise over 10 minutes under stirring. Then, the temperature was raised to 95 ° C. under stirring and heat treatment was performed to obtain an acrylic resin having an average particle diameter of 200 μm. The weight average molecular weight of the acrylic resin was 60,000.

<Manufacturing example of a master batch of thermally expandable microcapsules 1>
48 parts of acrylic resin obtained above, 12 parts of acrylic plasticizer (manufactured by Toa Synthetic Co., Ltd., "Alfon UP1020", weight average molecular weight 2000, viscosity at 25 ° C. 500 mPa · s, all acrylic, non-functional group), And 40 parts of heat-expandable microcapsules (manufactured by Kureha Co., Ltd., "Microsphere S2640D", average particle size 21 μm, maximum expansion temperature 249 ° C.), set in a heavy-duty feeder, and mesh in the same direction for biaxial extrusion. A masterbatch of pellet-shaped heat-expandable microcapsules was obtained by supplying the mixture to a machine (Technobel, 25 mm extruder), melt-kneading at 130 ° C., cooling the strands with water, and cutting the strands with a pelletizer. The carrier resin composition used in the preparation of the masterbatch had compatibility with polycarbonate and had a shear viscosity of 60 × 10 ⁴ Pa · s at 80 ° C. In addition, the workability of the masterbatch was also good.

<Production Example 1 of Polyester-Polyester Copolymer>
A reactor equipped with a stirrer and a gas outlet, polyethylene terephthalate (IV = 0.65) manufactured with a germanium-based catalyst, and a 30 mol adduct of bisphenol A ethylene oxide (manufactured by Toho Kagaku Co., Ltd., "Bisol 30EN", general It corresponds to the polyether unit represented by the formula (6), and n + m is 30), based on the total amount of polyethylene terephthalate and 30 mol of bisphenol A ethylene oxide adduct, 400 ppm of germanium dioxide, stabilizer ( Irganox 1010) 2000 ppm manufactured by Ciba Specialty Chemicals was charged, held at 270 ° C. for 2 hours, then depressurized with a vacuum pump, subjected to polycondensation with 1 torr, and the depressurization was terminated when the predetermined degree of polymerization was reached. Then, the reaction was stopped, the produced product was taken out, and the strands cooled in the water tank were post-crystallized and dried at the same time in a hot air dryer set at 100 ° C., and then put into a crusher for pelletization. By chemistry, a pelleted polyester-polyethylene copolymer was obtained. The obtained polyester-polyether copolymer had a polyether content of 30% and an IV value of 0.45. The IV value of the polyester-polyether copolymer was calculated from the logarithmic viscosity at 25 ° C. and 0.5 g / dl in a mixed solvent of tetrachloroethane / phenol = 50/50 (weight ratio).

<Production Example 1 of Polycarbonate Resin Composition>
50 parts of polycarbonate ("S-2000" manufactured by Mitsubishi Chemical Corporation, number average molecular weight 23,000), 15 parts of thermoplastic polyester resin ("Belpet EFG70" manufactured by Bell Polyester Products Co., Ltd., polyethylene terephthalate), above. 15 parts of the polyester-polyether copolymer obtained in the above, and 15 parts of the inorganic compound (Mica, "YM-21S" manufactured by Yamaguchi Mica Co., Ltd., number average particle diameter 27 μm) are meshed in the same direction to a twin shaft extruder (Japan Steel Works) It was supplied to TEX44) manufactured by Japan Steel Works, melt-kneaded at 280 ° C., the strands were cooled with water, and then cut with a pelletizer to obtain a polycarbonate-based resin composition as a pellet-shaped base material component. A polycarbonate resin composition was obtained by hand-blending 95 parts of the obtained polycarbonate-based resin composition as a base material component and 5 parts of the masterbatch of the heat-expandable microcapsules obtained above.

(Example 1)
<Manufacturing of injection foam molding>
The polycarbonate-based resin composition obtained above was injection-foam molded to prepare an injection-foam molded product. Specifically, the polycarbonate-based resin composition obtained in Production Example 1 is supplied to an electric injection molding machine (manufactured by Toyo Kikai Kinzoku Co., Ltd.) having a core back function and a shut-off nozzle with a mold clamping force of 180 tons. After melt-kneading at a cylinder temperature of 270 ° C and a back pressure of 10 MPa, it is composed of a fixed type set at 60 ° C and a movable type that can move forward and backward, and has a flat plate-shaped cavity (initial cavity) of 160 mm in length and 160 mm in width. A mold having a clearance t ₀ = 2.4 mm and a direct gate of φ8 mm at the center of the bottom surface was injected and filled at an injection speed of 100 mm / sec. After injection filling is completed up to the initial filling thickness (initial cavity clearance t ₀ ), the bottom surface can be moved to the desired thickness (foaming magnification) (clearance is such that the cavity clearance t _f after core back is 3.6 mm). The mold was retracted to foam the polycarbonate resin composition in the cavity. After the foaming was completed, the injection foam molded product was taken out after cooling for 40 seconds. The foaming ratio was 1.5 times. The movable surface was provided with one engraving for forming the reinforcing rib 3 having the shape of the cross section shown in FIG.

(Example 2)
As the movable mold of the mold, injection is performed in the same manner as in Example 1 except that a movable mold provided with two engravings for forming the reinforcing rib 3 having the shape of the cross section shown in FIG. 3 is used. A foam molded product was produced. The distance between the adjacent reinforcing ribs 3 was 7 mm.

(Comparative Example 1)
As the movable mold of the mold, a movable mold provided with one engraving for forming the reinforcing rib 13 having the shape of the cross section shown in FIG. 6 was used, except that the movable mold was used in the same manner as in the first embodiment. An injection foam molded product 11 having a main body portion 12 and reinforcing ribs 13 was produced.

The surface impact strength and the sink mark on the design surface side of the injection foam molded product obtained in Examples and Comparative Examples were measured and evaluated as described above, and the results are shown in Table 1 below. Table 1 below also shows the dimensions of the reinforcing ribs.

As can be seen from Table 1, in the examples, a thermoplastic resin molded product having high surface impact strength in a low temperature environment and no appearance defects such as sink marks was obtained. Further, in the embodiment, the weight is reduced by forming the main body 2 with a thermoplastic resin foam. When the cross section of the deep center of the main body of Example 1 was observed with a scanning electron microscope (SEM) (manufactured by JEOL Ltd., model number "6060LA"), as shown in FIG. 8, uniform fineness of 100 μm or less. The presence of closed cells was observed.

On the other hand, in the comparative example, the tip portion of the reinforcing rib 13 does not have a radius of curvature at both corners and does not have an arc shape, so that the obtained thermoplastic resin molded product is in a low temperature environment. The surface impact strength was low.

1,11 Thermoplastic resin molded

body

2, 12

Main body

3, 13 Reinforcing rib T1 Main body thickness T2 Average thickness of reinforcing rib T3 Maximum thickness of reinforcing rib T4 Thickness of flat part at the tip of reinforcing rib Ra Radius of curvature of the joint between the reinforcing rib and the main body Rb Radius of curvature of the corner at the tip of the reinforcing rib Rc, Rd Radius of curvature of the tip of the reinforcing rib

Claims

In a main body portion made of a thermoplastic resin foam and a thermoplastic resin molded body provided with reinforcing ribs formed on the back surface side of the main body portion.
When observing the cross section of the reinforcing rib, the root portion of the reinforcing rib bulges outward, so that the joint portion between the reinforcing rib and the main body portion has a curved shape, and the reinforcing rib is used for reinforcement. The tip of the rib has a radius of curvature at both corners or is arcuate.
The thickness T1 of the main body is 1.8 mm or more and 6.0 mm or less.
The radius of curvature Ra of the joint is 0.05 mm or more and 2.2 mm or less.
A thermoplastic resin molded product, wherein the ratio T3 / T1 of the thickness T1 of the main body to the maximum thickness T3 of the reinforcing rib is larger than 0.25 and 0.75 or less.
The thermoplastic resin molded product according to claim 1, wherein the tip portion of the reinforcing rib has a shape having a radius of curvature Rb at both corners, and the radius of curvature Rb of the corner is 0.05 mm or more and 2.2 mm or less. ..
The claim that the tip of the reinforcing rib has a shape of a true arc having a radius of curvature Rc of 0.05 mm or more and 2.2 mm or less, or an elliptical arc having a radius of curvature Rd of 0.05 mm or more and 9.5 mm or less. The thermoplastic resin molded product according to 1.
The thermoplastic resin molded product according to any one of claims 1 to 3, wherein the average thickness T2 of the portion of the reinforcing rib excluding the tip portion and the root portion is 0.2 mm or more and 4.3 mm or less.
The thermoplastic resin molded product according to any one of claims 1 to 4, wherein the height H of the reinforcing rib is 2 mm or more and 15 mm or less.
The thermoplastic resin molded product according to any one of claims 1 to 5, wherein the ratio H / T2 of the height H of the reinforcing ribs to the average thickness T2 of the reinforcing ribs is 0.4 or more and 75 or less.
The reinforcing ribs are arranged so that the longitudinal direction is along the longitudinal direction of the thermoplastic resin molded product, and the widthwise distance between adjacent reinforcing ribs is 3 mm or more and 20 mm or less. The thermoplastic resin molded article according to any one of.
The thermoplastic resin molded product is an injection foam molded product, and the specific gravity of the thermoplastic resin molded product is 0.3 g / cm 3 or more and 1.2 g / cm 3 or less, or the foaming ratio of the main body is 1.1 times. The thermoplastic resin molded product according to any one of claims 1 to 7, which is 3.0 times or more.
The thermoplastic according to any one of claims 1 to 8, wherein the length of the thermoplastic resin molded product is 200 mm or more and 3000 mm or less, and / or the width of the thermoplastic resin molded product is 50 mm or more and 3000 mm or less. Resin molded body.
The thermoplastic resin molded product according to any one of claims 1 to 9, wherein the value of the surface impact strength measured by the following method for measuring the surface impact strength is 1.9 J or more in the thermoplastic resin molded product.
(Measurement method of surface impact strength)
The inside of the built-in chamber is set to an environment of −30 ° C., a DuPont impact test (measured according to ASTM D 2794) is performed, and 50% fracture energy is calculated to obtain the surface impact strength. The impact is applied to a portion directly below the reinforcing rib provided on the non-design surface side on the side where the reinforcing rib is not formed (design surface side).
The thermoplastic resin molded product according to any one of claims 1 to 10, wherein the thermoplastic resin molded product contains polycarbonate and / or ABS resin.
The thermoplastic resin molded product according to any one of claims 1 to 11, wherein the thermoplastic resin molded product is a foam molded product of a thermoplastic resin composition containing a heat-expandable microcapsule.
The claim that the thermoplastic resin molded product is one or more selected from the group consisting of automobile parts, exterior parts of OA equipment, internal mechanical parts of OA equipment, exterior parts of home appliances, and internal mechanical parts of home appliances. The thermoplastic resin molded product according to any one of 1 to 12.
The thermoplastic resin molded product according to claim 13, wherein the automobile parts are one or more selected from the group consisting of exterior parts and outer panel parts.
The method for producing a thermoplastic resin molded product according to any one of claims 1 to 14.
A method for manufacturing a thermoplastic resin molded body, which comprises a step of integrally molding the main body and reinforcing ribs by injection molding to obtain a thermoplastic resin molded body.