JPS604550A - Polycarbonate resin composition for molding - Google Patents

Abstract

PURPOSE:To provide the titled composition giving a molded article having improved adhesivity with paint and printing ink, by compounding a polycarbonate resin with a specific aromatic carbonate oligomer together with a glass filler. CONSTITUTION:The objective composition is produced by compounding (A) an aromatic polycarbonate resin with (B) a glass filler (glass fiber, glass flakes, glass beads, etc.) and (C) an aromatic carbonate oligomer composed of the recurring structural units of formula (R1, R2, R3 and R4 are H, halogen or 1-3C alkyl; X is 1-5C alkylidene, O, S or sulfonyl) and having an average polymerization degree of 2-15. The content of the component B in the whole composition is 5-50wt%, preferably 8-40wt%, and that of the component C is 2- 30wt%, preferably 5-20wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glass-reinforced polycarbonate resin composition suitable for molding, which has improved adhesion of paint, printing ink, etc. to the surface of a glass-reinforced polycarbonate resin molded product.

Polycarbonate resin reinforced with glass-based fillers (hereinafter referred to as [glass-reinforced polycarbonate resin]) exhibits various excellent performances such as dimensional stability, mechanical strength, heat resistance, and electrical properties, so it is used in cameras, VTRs, It is used in a wide range of industrial fields such as facsimile.

However, despite its excellent performance, injection molded products using glass-reinforced polycarbonate resin do not have a beautiful appearance. In this case, it is necessary to rely on secondary processing such as painting or printing in order to give the molded product a good appearance, and as a result, the adhesion between the base material and the coating film or printing ink has become a problem.

For molded products using glass-reinforced polycarbonate resin,
Unlike when using non-reinforced polycarbonate resin,
Even if a paint exhibits good adhesion to a molded article made of unreinforced polycarbonate resin, satisfactory adhesion may not be obtained in some cases.

As a result of investigating the cause, the present inventors found that it is caused by a unique condition of the surface layer of the glass-reinforced polycarbonate resin molded product.

That is, when a glass-reinforced polycarbonate resin molded product obtained by injection molding was used, and cellophane tape was attached to the surface of the product and the tape was rapidly peeled off, the surface layer was observed to peel off in an wafer-like manner. In order to explain the state, the results of observing the surface with a scanning electron microscope are shown as Photo 1 (before adhesion of cellophane tape) and Photo 2 (after peeling). This phenomenon is more likely to occur when the surface of a molded article is made as smooth as possible with the intention of painting it. Furthermore, when a coating is applied onto the smooth surface of a molded article, the coating film peels off together with the underlying layer, that is, the surface layer of the molded article, for the reasons mentioned above. In this case, if the coating film is made thinner to reduce costs,
It was found that the effect was even more pronounced.

The inventors of the present invention have carried out intensive studies to solve these drawbacks of glass-reinforced polycarbonate resin, and as a result, by blending a specific aromatic carbonate oligomer into a mixed system of aromatic polycarbonate resin and glass filler, The present invention was completed based on the discovery that a glass-reinforced polycarbonate resin composition can be obtained which solves the above-mentioned defects and gives molded products with excellent adhesion to paints, printing inks, etc.

In order to clarify the features of the resin composition of the present invention, it will be explained using a photograph taken by a scanning electron microscope of a fractured surface including the surface layer of a molded article obtained using the resin composition of the present invention. First, Photo 3 shows a fractured surface including the surface layer of a molded article obtained using the resin composition of the present invention, and as can be seen from this photo, cavities are observed around the glass fibers, which are This means that the resin and glass fiber are not in close contact. Furthermore, when each part of the fractured surface is observed in detail, it is surprisingly found that the skin layer near the surface of the molded article is formed almost entirely of resin, unlike the inner layer. On the other hand, when looking at Photo 4, which shows the fractured surface including the surface layer of a molded product obtained using a resin composition consisting only of polycarbonate resin and glass fiber, which causes peeling of the surface layer of the molded product, it is found that the surface layer of the molded product peels off. There is virtually no difference between the inner layer and the inner layer, and it can be seen that glass fibers are present in the surface layer as well.

As is clear from these observations, when the resin composition of the present invention is used, the glass fibers are submerged from the skin layer to the inner layer due to the unique effect of the aromatic carbonate oligomer, making it look like a two-layer injection molding with two cylinders. The result is a molded product in which the skin layer and internal layer are separated, as if it had been molded by a machine.

In this way, the surface layer of the injection molded product obtained using the resin composition of the present invention becomes strong and has cellophane tape peeling resistance, and the adhesion between the paint or printing ink and the molded product surface is significantly improved. It has now been improved.

The aromatic polycarbonate resin used in the present invention is
2. One or two dihydric phenolic compounds typically exemplified by 2-bis(4-hydroxyphenyl)-propane and 2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane. It is a known polymer obtained by reacting a carbonate precursor typically exemplified by phosgene with a carbonate precursor by a known method, and its preferred molecular weight is 19,000 to 3,000 in terms of viscosity average molecular weight.
The range is 0.

Next, the glass-based filler used in the present invention refers to a filler selected from the group consisting of glass fiber, glass beads, and glass flakes, and these may be used alone or in combination. 5-15μm, length 0.0
It is a short fiber with a length of 2 to 10 (turns).For example, Asahi Fiber Class ■ product name [Glasron Chopped Strand] or "Glasrono Milled Fiber" or Nippon Sheet Glass ■ product name [Micro Glass Chopped Strand]. Glass beads are spherical with an outer diameter of 10 to 100 μm.
For example, manufactured by Toshiba Barotech II, product name 1-E GB
Examples of glass flakes include those commercially available as 731J, etc., and the glass flakes are plate-shaped with a thickness of 1 to 20 μm and a side length of 0.05 to 1.0 mm, such as those manufactured by Nippon Sheet Glass. , Product Name 1 Micro Glass Flake CE
Examples include those commercially available as F-48j and the like.

The amount of the glass filler added is 5 to 5 in the total amount of the composition of the present invention.
It is sufficient to select it within a range in which it accounts for 50% by weight; if it is less than 5%, it will be inferior in terms of dimensional stability (low shrinkage rate), strength, or rigidity, and will not function as a glass reinforced resin material. On the other hand, if it exceeds 50 inches, the fluidity will be insufficient, making it difficult to mold, and the abrasion of the mold and cylinder will be severe, resulting in an economical disadvantage. The most preferable range is
8-40 weight section is hereditary.

Further, the aromatic carbonate oligomer used in the present invention refers to a low molecular weight polycarbonate having an average of 2 to 15 repeating structural units represented by the following formula.

Formula (wherein R2, R2, and R4 are each a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms, and each may be the same or different,
And X is a substituted or unsubstituted alkylidene group having 1 to 5 carbon atoms, an oxygen atom, a sulfur atom, or a sulfonyl group. ) This aromatic carbonate oligomer has 2゜2-bis(
4-hydroxyphenyl)propane, 2,2-bis(3
, 5-dibromo-4-hydroxyphenyl)propane,
2. Obtained by the reaction of an aromatic dihydric phenol compound typically exemplified by 2-bis(3゜5-dimethyl-4-hydroxyphenyl)propane with a carbonate precursor typified by phosgene. The hydric phenolic compounds may be used alone or in combination, and the oligomers are generally oxidized in methylene chloride at 25°C.
, 3 It is a low molecular weight substance with an intrinsic viscosity of 3 or less. When preparing this oligomer, the molecular weight may be adjusted by, for example, adding phenol and/or alkyl-substituted phenol to the polymerization system to block the ends in an interfacial polymerization method using phosgene.

The amount of the aromatic carbonate oligomer thus obtained may be selected within the range of 2 to 30 parts by weight based on the total amount of the composition of the present invention, and if it is less than 2 parts, it will affect the cellophane in the surface layer of the molded article. It is hardly effective in preventing tape peeling, and on the other hand, if it exceeds 30 minutes, the average molecular weight of the entire polycarbonate resin constituting the composition decreases, causing problems in physical properties such as stress cranking properties, which is disadvantageous. It is.

The most preferable range is 5 to 20 weight class and hereditary.

There are no particular limitations on the method for producing vI4g of the composition of the present invention; for example, after sufficiently mixing the polycarbonate resin, carbonate oligomer, and glass fiber in a V-type blender, pelletizing the mixture in a vent-type uniaxial extruder. Prepare a mixture of polycarbonate resin and carbonate oligomer thoroughly mixed in advance using a powerful mixer such as a super mixer, and when extruding this using a vented twin-screw extruder, start from the middle of the extruder. As for the method of supplying, mixing, and extruding the glass fibers into pellets, methods generally used in industry can be applied.

In addition, lubricants such as fatty acid esters, paraffin wax, and silicone oil; internal plasticizers such as polyethylene, ABS, and polyethylene terephthalate; and various other additives may also be added to this composition as necessary.

Comparative examples and examples will be specifically described below.

Example 1 [Manufacture of aromatic carbonate oligomer (number average degree of polymerization: 7)] In a reaction tank with a capacity of 400 tons equipped with a stirrer, a phosgene gas blowing pipe, and a cooling jacket, 48 weight hereditary caustic soda aqueous solution 25 to 9, water 250 tons methylene chloride 60L, Hydrosulfide 1002 and Bisphenol 27.5 were added sequentially, and while maintaining the liquid temperature in the range of 15°C to 20°C, phosgene 15 was blown in for 30 minutes to react.Then, 48% by weight was added to the reaction system.
A solution prepared by dissolving 6 parts of aqueous sodium hydroxide solution, 100 parts of triethylamine, and 5.2 parts of p-tert-butylphenol in 50 tons of methylene chloride was added, and stirring was continued for an additional 60 minutes.

The precipitated methylene chloride phase was extracted and transferred to a 600 L tank equipped with a stirrer, neutralized with a 1007.01 phosphoric acid aqueous solution and water, and washed with water. The purified methylene chloride solution was transferred to a solidification tank with an internal capacity of 500 tons, and stirred with 300 tons of water to reduce heat, and methylene chloride was distilled off. After cooling, the precipitate is separated and dried,
55.6 kg of aromatic carbonate oligomer powder was obtained.

The melting point of the obtained carbonate oligomer is 229-2
At 32°C, the viscosity average molecular weight is 5 x 1000, and the number average molecular weight by end group analysis is 2.1. It was X100O.

Example 2 [Manufacture of aromatic polycarbonate oligomer (number average degree of polymerization 10)] In the manufacturing method of Example 1, the amount of phosgene was changed to 14.6K.
53 Kq of aromatic carbonate oligomer powder was obtained in exactly the same manner except that the amount of g, p-tert-butylphenol was changed to 3.6 odors. The melting point of this thing is 235~
At 238°C, the viscosity average molecular weight was 7X(000) and the number average molecular weight was 2.9X1000.

Examples 3 to 7 and Comparative Examples 1 to 2 Polycarbonate resin powder, glass filler, and aromatic carbonate oligomer obtained in Example 1 were mixed in a tumbler in the proportions shown in Table 1. −
It was pelletized using a vented shaft extruder. The obtained pellets of each composition were dried for 6 hours in a hot air circulation dryer at 120° C., and then molded into cylindrical molded products using a Neomatsu 350/120 injection molding machine manufactured by Sumitomo Heavy Industries. The molded product is a cylindrical molded product with an outer diameter of 8 fins, a thickness of 2 and a height of 25 tanJ), and the molding conditions are resin temperature of 320°C, mold temperature of 9.
0-100℃, holding pressure 1000%, injection speed 60 m
m/s and a molding cycle of 50 seconds (cooling time 25 seconds, injection time 1 second and hold time 7 seconds).

The obtained molded product was subjected to a peel test on the surface of the molded product using cellophane tape and a base grain test after painting, and the results are summarized in Table 1.

As is clear from Table 1, it is recognized that the adhesion of the coating film of the molded article using the composition of the present invention is improved.

Note) 1) Glass fiber: Made by Asahi Fiberglass■, A is the product name "Glasron Chomp Dostra □nd", B is the product name [Glasron Milled Fiber] Glass beads: Made by Toshiba Varo Teini ■, product name rEGB
7.31J Glass flakes: manufactured by Nippon Sheet Glass ■, trade name [Micro Glass Flake CBF48J2] rNGJ in which oblate-like peeling was clearly observed, and rNGJ in which peeling was more difficult to notice were identified as "OK".

3) Plastic paint made by Ohashi Chemical ■ (100 people x-
1/Hardening agent scrap 5/Thinner 5600) was used for spray painting. The curing conditions were 80° C., and the coating thickness for 2 hours was 18 to 23 μm.

Surface condition of a carbonate resin molded article (molded article) Scanning electron microscope of the surface condition after peeling the same Scanning electron microscope of the fractured surface including the surface layer of an injection molded article obtained using the resin composition This photograph shows that a skin layer that does not contain glass fibers is formed. In both cases, the magnification is 300x.

The electron microscope used was a J8M255-type manufactured by JEOL ■.

1...Surface 2...Skin layer 3...Glass fiber 4...Matrix resin patent applicant Representative of Mitsubishi Gas Chemical Co., Ltd. Kazuyoshi Nagano1, Indication of the case 1982 Patent Application No. 1115492, Name of the invention Polycarbonate resin composition for molding3, Person making the amendment Relationship to the case Patent applicant address (100) Chiyoda-ku, Tokyo Marunouchi 2-5-2 Noboru - 11 Detailed explanation of the invention in the specification" column, 5 simplified drawings
, - Contents of amendment (1) The following amendments are made to the "Detailed Description of the Invention" column of the specification.

■ Correct "Observation" in the third line of page 4 to "Observation (JEOL Q1 word, JSM255-n type, 300x)".

■Correct "Photograph" in the 4th line of the 4th page and the 5th line of the same page to "Drawing".

■Correct "Photo 3" in the 6th line of page 5 to "Drawing 3".

■ Change “Photo” in the 8th line of page 5 to “Drawing (photo)” +
li jE.

■Correct "Photo 4" on page 5, line 18 to "1 drawing 4".

(2) The entire text of the "Brief Description of Drawings" column of the specification is amended to the following text in parentheses.

[Figures 1 to 4 show the dispersion state of the gas fibers in the resin molded product and the resulting state of the surface structure of the resin molded product on the glass fiber reinforced polycarbonate 1 projected with a scanning electron microscope.] , Figure 1 shows the surface of the conventional formulation, Figure 2 shows the surface of the item shown in Figure 1 with cellophane tape pasted and peeled off, and Figure 3 shows the fractured surface including the surface of the item of the present invention. , FIG. 4 shows a fractured surface including the surface of a conventional product.

It can be seen that the molded article of the present invention shown in FIG. 3 has a skin layer that does not contain glass fibers.

The numbers in the figure indicate the following, respectively: 1-Surface layer 2-Skin layer 3-Glass fiber 4-Matrix resin. The electron microscope used was a model JSM255-n manufactured by JEOL Ltd., and the magnification was 300 times.'' (3) The ``Drawings'' in the attached documents of the specification store were corrected as shown in the attached sheet.

Arithmetic 1st 寥2＠ Three people together 'IJ, 4-@ ’, −゛1v　’j2. 13,゛

Claims (1)

[Claims] 1. A composition comprising (a) an aromatic polycarbonate resin, fb) a glass filler, and (c) an aromatic carbonate oligomer having an average of 2 to 15 repeating structural units represented by the following formula: A polycarbonate resin composition for molding, wherein the tb+ component accounts for 5 to 50% by weight of the total composition, and the component (c) accounts for 2 to 30% by weight of the total composition. Formula (wherein R++ 'R2, R5 and fL4 are each a hydrogen atom, a halogen atom or an alkyl group having 1 to 3 carbon atoms, and each may be the same or different, and X is A substituted or unsubstituted alkylidene group having 1 to 5 carbon atoms, an oxygen atom, a sulfur atom, or a sulfonyl group.) (2) The lath-based filler is selected from the group consisting of glass fibers, glass flakes, and glass peas. The resin composition according to scope 1.