JPH0267350A - Resin composition and molding product thereof - Google Patents

Abstract

PURPOSE:To obtain a resin composition which can give a molding improved in impact resistance and capable of penetration printing by mixing a styrene resin with a thermoplastic polyester resin, an aromatic polycarbonate resin and a polyamide resin. CONSTITUTION:A resin composition is obtained by mixing 10-90wt.% styrene resin (e.g. acrylonitrile/butadiene/styrene resin) with 10-90wt.% thermoplastic polyester resin (e.g., polybutylene terephthalate) and 1-80wt.% aromatic polycarbonate resin [e.g., a reaction product of 2,2-bis(4-hydroxyphenyl)propane with phosgene] and 1-80wt.% polyamide resin (e.g., nylon 6). This composition is molded and printed by penetration printing, and the print is heat set.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a composition comprising a styrene resin (A), a thermoplastic polyester resin CB), an aromatic polycarbonate resin (C), and a polyamide resin CD), and its composition. This invention relates to a molded product obtained by applying penetration printing to a molded product obtained from a product.

Such compositions have excellent impact resistance and are capable of extremely good penetration printing, so they can be used to print letters, designs, symbols, etc. on push-button keys of computers, word processors, typewriters, telephones, calculators, etc. It is particularly suitable for key tops used by penetrant printing on the surface of keys.

[Conventional techniques and problems] Methods for molding letters, designs, symbols, etc. on the surface of key top molded products include printing methods such as dry offset printing, silk screen printing, and pad printing, and molded product materials of different colors. A two-color molding method is conventionally known, in which letters, designs, symbols, etc. are first injection molded, and then a material is poured around the first molded product to form a key top molded product.

However, with the printing method, ink is simply attached to the molded product, so it is not possible to mold characters, designs, symbols, etc. with sufficient wear resistance. The cost increases because another mold is required, and it is difficult to make complex characters, designs, symbols, etc., and there is a limit to reducing the thickness of the molded product, making it very expensive. Recently, as a solution to this problem, the penetrant printing method, that is, using ink mixed with sublimable dye, is used to print characters on the transfer paper in advance by screen printing or pad printing.
There is a method in which a pattern, symbol, etc. is printed, placed on a molded key top, and further heat-pressed to allow the dye in the ink to penetrate and fix inside the molded product, or by using the special ink mentioned above. After printing letters, designs, etc. directly on the molded product using pad printing or screen printing methods, the dye in the ink penetrates into the inside of the molded product by heating it in a heating furnace, etc., and removes unnecessary ink components. A method of cleaning with a solvent is being put into practical use. If this type of penetrant printing is performed, the dye penetrates into the inside of the resin, so it has excellent abrasion durability, there is no buildup of ink due to ink adhesion, and the touch of the key is good, and it can print with a wide variety of complex characters, designs, etc. Symbols and the like can be easily molded onto the molded product, reducing costs. However, the resins that can be used for molded products are limited. In other words, depending on the resin, heat treatment is applied, which may cause deformation or distortion of the molded product due to the resin's lack of heat resistance, poor durability due to insufficient penetration depth due to poor dye penetration, or characters, designs, and symbols due to dye diffusion. smearing occurs. For this reason, only some resins such as polybutylene terephthalate resin and polyethylene terephthalate resin are currently in practical use.

In addition, since polybutylene terephthalate resin and polyethylene terephthalate resin are crystalline polymers, molding is difficult, and if the crystalline states of the molded products are not similar, the color of the molded products after ink penetration will be different. As a result, adjacent keys on the keyboard have different colors, making it visually confusing.

Furthermore, other resins such as ABS resin are blended with these polyalkylene terephthalate resins such as polybutylene terephthalate resin and polyethylene terephthalate resin, and printing is applied to molded products (Japanese Patent Laid-Open No. 63-9848
However, the method 2) has the above-mentioned problems, and furthermore, a product simply blending polyalkylene terephthalate and ABS resin has poor thermal stability, making it very difficult to obtain a molded product. Furthermore, the obtained molded products do not have sufficient impact strength, bending strength, etc., and there is a strong desire to develop a resin that has sufficient mechanical, physical, and chemical properties and is durable for practical use.

[Means for solving problems]

The present inventors have made extensive studies to solve these problems and obtain excellent penetration printable resin compositions and molded products. As a result, we have found that 10 to 90 wt. (B) 10 to 90% by weight, aromatic polycarbonate resin (C) 1 to 80% by weight, and polyamide resin 1 to 80% by weight. We have discovered that this is possible and have arrived at the present invention.

The styrenic resin (A) used in the present invention is a styrene polymer or styrene copolymer, such as acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (As) resin, methyl methacrylate-butadiene-styrene (MBS). ) resin, acrylonitrile-EPDM-styrene (AES) resin, butadiene-styrene (HIPS) resin, polystyrene resin, etc., and some or all of these styrene parts [α
-Methylstyrene or N-phenylmaleimide is a commonly used method, and such modified styrenic resins can also be used in the molded articles of the present invention. These resins may be used alone or in a mixture of two or more.

Next, in the present invention, the thermoplastic polyester resin (B) blended into the styrene resin is the polycondensation of a dicarboxylic acid compound and a dihydroxy compound, the polycondensation of an oxycarboxylic acid compound, or the polycondensation of a mixture of these three components. They are homopolyesters, copolyesters, etc. obtained by methods such as polyalkylene terephthalate, preferably polyalkylene terephthalate, and polybutylene terephthalate and polyethylene terephthalate can be used alone or in combination, and exhibit remarkable effects.

Further, the aromatic polycarbonate to be blended with the styrenic resin in the present invention can be produced by reacting dihydric phenol with phosgene or carbonic acid diester. As the dihydric phenol, bisphenols are preferable, and 2,2-bis(4-hydroxyphenyl)propane is particularly preferable.The aromatic polycarbonate is a homopolymer of dihydric phenols, a copolymer of two or more types of dihydric phenols, or It is selected from copolymers in which a portion of carbonic acid is replaced with other dibasic acids (eg, terephthalic acid, isophthalic acid), but two or more types may be combined.

Further, the polyamide used in the present invention is a self-polymerized metal of lactam, a polycondensed metal of diamine and dibasic acid, a self-polycondensed product of ω-amino acid, or a copolymer thereof, such as nylon 6, nylon 11, 6.6 nylon, 6/
Examples include 6.6 nylon, 6/10 nylon, etc., and 6.6 nylon and 6.6 nylon
Nylon is suitable, but is not particularly limited.

In the present invention, a molded product made by blending the above-mentioned styrene resin (A), thermoplastic polyester resin (B), aromatic polycarbonate resin (C), and polyamide resin (D) is subjected to penetrant printing, and an excellent This method is characterized by obtaining a molded product with permeation printing, and the blending ratio of each component for obtaining this molded product is styrene resin (A)/thermoplastic polyester resin (B)/ Aromatic polycarbonate resin (C)/polyamide resin (D) -10 to 90/10
~90/1~80/1~80 (wt%), preferably 2
0~80/20~8015~6015~60 (weight%)
, more preferably 20-70/20-7015-501
5-50 (wt%), more specifically 20-60/20-6
The optimum value is often in the range of 015-4015-40.

Further, in the present invention, known additives and/or fillers can be added to the above-mentioned composition constituting the molded article within a range that does not significantly impair the penetrant printability.

Crystallization promoters and antioxidants such as talc, gypsum, silica, calcium carbonate, alumina, titanium dioxide, finely divided metals, powdered glass, carbon black, graphite, polyolefins, calcium benzoate, magnesium stearate, and Teflon. , various stabilizers, lubricants, plasticizers, mold release agents, antistatic agents, surfactants, etc.

There are no particular restrictions on the method for preparing the composition of the present invention, and any commonly used method can be used.

For example, after all the components are mixed at once, they are melt-kneaded and pelletized using an extruder, and then molded.

Furthermore, the penetrant printing method used in the present invention is not particularly limited, and after printing letters, designs, symbols, etc. on transfer paper using special ink mixed with sublimable dye, the printed transfer paper is Letters, designs, symbols, etc. can be printed directly onto the molded product by placing it on the molded product and heat-pressing it, allowing the dye in the ink to penetrate into the inside of the molded product, or by pad printing, screen printing, etc. using the above ink. After printing, a method of fixing using a heating furnace or the like can be used.

〔Example〕

The present invention will be specifically explained with reference to Examples. The penetration printing method, evaluation method, etc. in the Examples and Comparative Examples shown below are as follows.

(1) Granulation is VC-40 manufactured by Chuo Kikai Seisakusho Co., Ltd.
A pellet was obtained using a vented single-screw extruder.

(2) Using the obtained pellets, a molded article was prepared and the physical properties were evaluated, and at the same time a molded article for permeation printing evaluation was obtained.

(3) Penetration printing evaluation test piece key top molded product 18X18X7■ (1,00x key) with grain (4) Penetration printing method Toyo Ink Co., Ltd. SMX PBT (black) F1 ink is used to print characters by silk screen printing Create a transfer paper, place it on the molded key top that has been preheated at about 150°C for 180 seconds, and then heat it 180° from above.
A heat-resistant rubber pad heated to C was applied pressure for 60 seconds to penetrate the dye into the molded product and fix it.

(5) Evaluation method i) Abrasion durability of printing section Sand eraser blocker 201 for electric eraser manufactured by Lion Office Machinery Co., Ltd.
The printed surface is reciprocated using a load of 350g, and the number of reciprocating movements until some of the characters disappear is 5,000 times or more. A: Less than 5,000 times, 3,000 times or more. B: Less than 3,000 times, 1,000 times. C,100 times or more
Less than 0 times were evaluated as D.

ii) Appearance and quality of the key top molded product immediately after penetrant printing and after penetrant printing.
After leaving it in a constant temperature and humidity chamber at 5°C and 195% RH for 240 hours, the appearance and quality were observed with the naked eye and with a magnifying glass.
Evaluated in stages. If the bleeding is less than 20% of the width of the printed characters, it is 1. If the bleeding is less than 40%, it is 2.
．． 60% or less: 3.80% or less: 4.80
Those exceeding % were given a score of 5.

1ii) Penetration: The permeated key top is immersed in liquid nitrogen, the temperature is lowered to below the Tg point of the key top material resin, and the key top is broken at the printed characters, symbols and figures on the key top surface, The cross section was observed using a TUM-200BD universal tool microscope manufactured by Tokyo Kogaku Kikai Co., Ltd., and the degree of ink immersion was read.

Those with a permeability of 30 μm or more are represented by A, those with a permeability of less than 30 μm and 20 μm or more are represented by B, those with a permeability of less than 120 μm and 10 am or more are represented by D, and those with a permeability of less than 110 μm are represented by D.

iv) Change in Resin Surface When a transfer paper was placed on the key top surface and a heat-resistant rubber pad was used to apply pressure, changes in the grained surface of the key top surface were observed. At this time, A
, B indicates that the condition of the grain has changed but can only be noticed by paying attention, and C indicates that the condition of the grain has clearly changed.
A case where the condition of the grain changes and the grain disappears is indicated by D.

〔Example〕

Examples of the present invention are shown below, but the present invention is not limited thereto. All percentages shown in the Examples and Comparative Examples are based on weight.

Example 1, Comparative Example 1 Table 1 shows the composition of the styrene resin. All values indicate weight %. Table 1 Styrenic resin and polyethylene terephthalate (PET) resin (Nippon Unipet Co., Ltd.)
RT-523C) and polybutylene terephthalate (
PBT) resin (manufactured by Agzo Corporation, TO6-202) and aromatic polycarbonate (PC) resin (manufactured by Mitsubishi Kasei Corporation, A
7020) IF) and polyamide (PA) resin (manufactured by Toshiku Co., Ltd., CM-1017) were granulated in the proportions shown in Table 2.

Next, a part of this pellet was used for measuring physical properties, and the rest was used to make a test piece (key top) by injection molding, which was subjected to penetration printing and evaluated. The results are shown in Table 2.

Example 2, Comparative Examples 2 to 4 B in which each of (A-5) and (A-7) was further mixed with the components (A-3), (A-4), and (A-6) in Table 1. The components were prepared and shown in Table 3. This B component is used as a styrene resin, and further PET resin, PBT resin, PC resin,
The PA resin was subjected to the same treatment as in Example 1 and evaluated. The results are shown in Table 4.

Example 3, Comparative Example 5 Using B-3 in Table 3 as the styrene resin, the same treatment as in Example 1 was performed and evaluated. The results are shown in Table 5.

〔Effect of the invention〕

As is clear from the above Examples and Comparative Examples, the composition containing a styrene resin, a thermoplastic polyester resin, an aromatic polyester resin, and a polyamide resin is a composition consisting of two types of styrene resin and a thermoplastic polyester resin. It also has better physical properties than a composition of a styrene resin, a thermoplastic polyester resin, and a polyamide resin composition that does not contain an aromatic polycarbonate resin. Compared to penetrant printing on molded products of two types of compositions, the penetrant printability is improved, and the ink bleeds significantly less due to heat treatment, etc.
It has become possible to obtain a penetrant-printed molded product with significantly less variation in the grain on the key top surface and excellent abrasion durability.

Patent applicant Denka Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. 10-90% by weight of styrene resin (A), 10-90% by weight of thermoplastic polyester resin (B), 1-80% by weight of aromatic polycarbonate resin (C), and 1-80% by weight of polyamide resin (D). ) A resin composition consisting of 1 to 80% by weight. 2. A molded article obtained by performing penetration printing on a molded article of the composition according to claim 1.