JPH0132050B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a specific amino resin and a specific specific amino resin for cleaning dirt on the mold surface in compression molding, transfer molding, injection molding, etc. of curable resin molding materials such as epoxy resin molding materials and phenolic resin molding materials. Regarding mold cleaning resin compositions containing mineral powder of It is possible to clean any mold, including molds, and the cleaning can be completed with just a few shots of dummy molding, and the curable resin molded product obtained by molding after cleaning has excellent appearance, gloss, and mold releasability when taken out of the mold. The present invention relates to a resin composition for mold cleaning, which is characterized in that a molded product can be obtained. If you continue molding the same material with the same mold for a long time, the surface of the mold will get dirty, and if you continue molding continuously, the surface of the molded product will get dirty, and the molded product will stick to the mold, causing molding problems. There were many cases where I was unable to continue working. These cleaning methods include cleaning the dirt on the mold surface during molding of curable resin molding materials.
Resin compositions for cleaning molds are known that use a melamine resin or a phenolic resin alone. For example, JP-A-48-79849 states that ``metallic soaps containing 10 parts by weight or more, waxes containing 5 parts by weight or more,
By heat molding using a molding material containing at least one type of mold release agent among oligomers of 0.5 parts by weight or more, the mold release agent is adhered to the mold surface and the mold is cleaned, followed by normal heat curing. A thermosetting resin molding method characterized by molding a thermosetting resin was proposed, and a melamine resin molding material filled with wood flour or cellulose fibers and a phenolic resin molding material were used individually as the thermosetting resin. is disclosed. However, the above proposal was aimed at making it easier to release the molded product for cleaning by mixing a large amount of mold release agent to the surface of the mold during molding. Incorporation of a large amount of molding agent has disadvantages such as reducing surface hardening, reducing gloss, and reducing gloss during the boiling test. Furthermore, the fluidity of the cleaning resin molding material is not necessarily good, and when cleaning a mold with a small gate and a complicated structure, the number of shots to clean the dirt increases, or the number of shots is difficult to clean. However, they also have drawbacks such as not being able to be cleaned thoroughly. In addition, JP-A No. 50-51 states, ``It is possible to prevent stains on the mold surface during molding of curable resin molding materials (excluding amino-based resin molding materials) by using materials mainly composed of amino-based resins. Accordingly, a method of cleaning has been proposed. This cleaning material contains 20 to 70 parts of amino resin, 80 to 30 parts of organic base material such as wood flour and pulp, and/or 80 to 30 parts of inorganic base material such as silica and charcoal.
0.5 to 5 parts of a mold release agent and, if necessary, a small amount of a coloring agent.The use of a urea resin or a melamine resin alone as an amino resin is disclosed. However, these cleaning materials have drawbacks such as insufficient cleaning effects because they are made of urea resin or melamine resin alone. As introduced above, in conventional proposals for mold cleaning resin compositions for cleaning dirt on the mold surface during molding of curable resin molding materials, amino resins such as melamine resins and urea resins and phenolic resins have been used. Several proposals have been made, such as those mentioned above, for use alone. However, these resin compositions for mold cleaning have various desired properties, such as a reduction in the time required to clean the mold, a property that does not wear or damage the mold, and an inherent ability to clean dirt on the mold surface. To have a sufficiently satisfactory combination of properties such as the ability to clean any mold such as a mold with a complex structure or a large mold, and the property to have no adverse effect on the product after cleaning. was extremely difficult in practice. The present inventors have conducted research in order to provide a mold cleaning resin composition that can solve the problems of having various properties desired for mold cleaning all at once. As a result, in contrast to the above-mentioned conventional proposals, which focused only on compositions using melamine resin, phenolic resin, urea resin, etc. alone as resins, it was found that a specific mixture of melamine resin and phenolic resin was used. It has been discovered that the above-mentioned problems can be solved all at once by using an amino-based resin consisting of the following and blending it with specific mineral powder. Therefore, the present invention provides a mold cleaning resin composition for removing dirt on the mold surface during molding of a curable resin molding material, the resin composition comprising:
The following (A) and (B), (A) an amino resin made by mixing 2 to 150 parts by weight of a phenol resin to 100 parts by weight of a melamine resin, and (B) an amino resin with a new Mohs hardness of 6 to 15. Contains mineral powder, and its flow hardening index _K20 value is 0.2
The present invention provides a mold cleaning resin composition having the above properties and a K ₁₀ value of 0.8 or less. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. As the amino resin used in the present invention, a mixture consisting of 2 parts by weight to 150 parts by weight, preferably 5 parts by weight to 120 parts by weight of a phenol resin is suitably selected and used based on 100 parts by weight of the melamine resin. . The melamine resin is obtained by condensing melamine and formaldehyde, and the phenol resin is obtained by condensing phenols and formaldehyde. In the present invention, a part of the melamine in the melamine resin is, for example, benzoguanamine,
It can be replaced with triazines other than melamine such as acetoguanamine, and the usage amount of such triazines other than melamine is generally the sum of melamine and triazines other than melamine.
An example is an amount of 30% by weight or less relative to 100% by weight. In addition to phenol, the above-mentioned phenols may also contain, for example, cresol, xylenol, ethylphenol, butylphenol, etc. The amount of phenols other than these phenols used is generally the same as phenol and phenol. An example is an amount of 30% by weight or less based on 100% by weight of the total amount with other phenols. moreover,
A part of the above formaldehyde can be replaced with aldehydes other than formaldehyde, such as paraform and acetaldehyde. Furthermore, the amino resin used in the present invention can be blended with a minor amount of other resins that can be blended therewith in an amount that does not adversely affect the improved properties of the composition of the present invention. Examples of such resins include alkyd resins, polyester resins, and acrylic resins. The mold cleaning resin composition of the present invention contains mineral powder having a new Mohs hardness of 6 to 15, preferably 6 to 13, in addition to the above-mentioned amino resin. Examples of such mineral powders include corundum,
Natural materials such as emery, garnet, and silica stone, and oxides or carbides such as silicon, iron, titanium, sodium, calcium, magnesium, aluminum, chromium, and boron are preferred, and these compounds include silicon oxide, magnesium oxide, Aluminum oxide, silicon carbide, boron carbide, etc. can be mentioned, and aluminum oxide, silicon oxide, silicon carbide, etc. are preferable, and silicon oxide, silicon carbide, etc. are more preferable. The particle size of the mineral powder is not particularly limited, but is generally #10 to #8000, preferably #50.
~#4000, more preferably #100~#2000. If the particle size is smaller than #8000, it tends to have drawbacks such as poor cleaning effectiveness and the generation of dust during handling, which worsens the working environment.If the particle size is larger than #10, it may cause damage to molds, uneven cleaning, etc. Defects are likely to occur. Further, the amount of the mineral powder used is not particularly limited, but is usually 10 parts by weight to 90 parts by weight, based on 100 parts by weight of the mold cleaning resin composition of the present invention.
Preferably 15 parts by weight to 30 parts by weight, more preferably
It is 17 parts by weight to 29 parts by weight. In addition to the mineral powder described above, the composition of the present invention also includes:
Other additives may be included, such as other inorganic or organic fillers, colorants, curing catalysts, lubricants, antioxidants, etc. Examples of such additives include, for example:
Other inorganic or organic fillers such as pulp, wood flour, vinylon fiber, glass powder, glass fiber, untreated calcium carbonate, tank, aluminum hydroxide, barium sulfate, zinc sulfide; for example, titanium oxide,
carbon black, zinc white, cadmium yellow,
Colorings such as inorganic pigments such as red iron, organic pigments such as phthalocyanine, azo, and diazo, fluorescent pigments such as benzoxazole, naphthotriazole, and comarin, and dyes such as anthraquinone, indico, and azo. agents; for example, organic acids such as phthalic anhydride, oxalic acid, sulfamic acid, para-toluenesulfonic acid, salts, inorganic acids such as sulfuric acid, the above acids and triethylamine, triethanolamine, β-dimethylaminoethanol, 2-methyl-2. Curing catalysts such as salts with amino-1-propanol, etc.; such as calcium stearate, zinc stearate, stearamide, methylolstearamide, methylene bisstearamide, paratoluenesulfonamide, cetyl alcohol, paraffin, silicone oil, etc. Lubricants; for example, antioxidants such as naphthylamine, diphenylamine, p-phenylenediamine, and thiobisphenol can be mentioned. As the pulp, straw pulp, bamboo pulp, wood pulp (softwood pulp, hardwood pulp), etc. are used, and either chemical pulp or mechanical pulp may be used. The size of the filler such as cellulose is not particularly limited, but is generally 5μ to 1000μ, preferably
Approximately 10μ to 200μ is preferable. In addition, the amount of cellulose is determined by the amount of the amino resin mentioned above.
For 100 parts by weight, 15 to 70 parts by weight, preferably 20 to 60 parts by weight are generally used. When preparing the composition of the present invention, amino resin,
Any means capable of uniformly mixing the mineral powder, optionally other secondary amounts of resin, and additives can be employed. For example, kneaders, ribbon blenders, Henshil mixers, ball mills, roll kneaders, crushers,
Examples include tumblers. The mold cleaning resin composition of the present invention has a fluid hardening index K ₂₀ value of 0.2 or more, preferably 0.3 or more, more preferably 0.35 or more, and a fluid hardening index K ₁₀ value of 0.8 or less, preferably must be 0.7 or less, more preferably 0.65 or less. If the _K20 value of the flow hardening index is less than 0.2, the cleaning effect may deteriorate, and if the _K20 value of the flow hardening index is greater than 0.8, the cleaning effect may deteriorate. Undesirable. Examples of curable resin molding materials that can be used to clean molds using the composition of the present invention include epoxy resin molding materials, phenolic resin molding materials, etc., and preferably epoxy resin molding materials, particularly epoxy resin molding materials for semiconductor encapsulation. It is a resin molding material. Furthermore, the mold cleaning resin composition of the present invention can be applied to any mold used in molding the thermosetting resin molding material, but generally iron, chrome, etc. More molds can be applied. Therefore, when the cleaning resin composition having the composition of the present invention is used for cleaning during actual molding of a thermosetting molding material, the cleaning resin composition can be used to clean the thermosetting molding material every several hundred to several thousand shots. By molding the resin composition several times, deposits on the molding mold can be automatically removed and the mold can be cleaned. This improves the molding cycle and reduces costs, bringing great industrial benefits to molders. Hereinafter, several embodiments of the resin composition for mold cleaning of the present invention will be explained in more detail with reference to Examples and comparative examples. In addition, in the following examples, the test method and evaluation are as follows. (1) Test method for cleaning effectiveness A commercially available epoxy resin molding material (Nitron MP manufactured by Nitto Denko Corporation) was used to mold an electronic circuit encapsulation molded product by transfer molding. After 200 shots and 400 shots are molded, a test mold cleaning resin composition is molded in the mold, and the number of shots and cleaning effect are investigated. The criteria for determining the cleaning effect are: 5: No clouding at all 4: Almost no clouding 3: Slight clouding 2: Clouding 1: Lots of dirt and defective parts in the molded product. (2) New Mohs hardness Select two reference ores (ores with known new Mohs hardness and different hardness) and finish each surface to a smooth plane with a diamond grindstone. Place each side together, put a small amount of mineral powder used to measure the new Mohs hardness between them, and rub it. When the powder is not used, the new Mohs hardness of the powder is assumed to be between those of the two reference ores. The new Mohs hardness based on standard ores is talc 1, fluorite 4, quartz 8, and diamond 15. (3) Particle size measurement method Particle size regulations are in accordance with JIS.R6001-(1973).
The measurement method is JIS.R6002. In addition, # (number or mesh) used in this specification means, for example, #1000 corresponds to number 1000 according to JIS.R6001, and the average diameter of the largest particle is 44 μm.
Below, the average diameter of the 30th particle from the largest particle is
It has a fine powder particle size distribution of 29μ or less and an average diameter of 18 to 14.5μ. (4) Method for measuring flow hardening index K ₂₀ and K ₁₀ values A mold used for the disk flow test specified by JIS (K-6911) was set at a surface temperature of 160°C, and 5 g of the resin composition was poured into the mold. Charge the disk so that it forms a mountain shape, press the disk under a total pressure of 10 tons without preheating, and measure its diameter (a). Next, when closing the mold, stop the mold at a distance of 1 mm, preheat it for 10 seconds, apply 10 tons of pressure, press the disk, and measure its diameter (b). Further preheating time is 20
Press the disk in the same manner as (b) in seconds and measure its diameter (c). Furthermore, the preheating time is set to 80 seconds, and the disk is pressed in the manner described in (b), and its diameter (d) is measured. The flow hardening index K ₂₀ value and K ₁₀ value are respectively K ₂₀ = (a) Diameter of the disk without preheating (mm) - (c) Diameter of the disk with 20 seconds of preheating (mm) / (a) Diameter of disc when not preheated (mm) - (d) Diameter of disc when preheated for 80 seconds (mm)
K ₁₀ = (a) Diameter of the disc when not preheated (mm) - (b) Diameter of the disc when preheated for 10 seconds (mm) / (a) Diameter of the disc when not preheated (mm) - (d) Diameter of disc when preheating for 80 seconds (mm)
It is indicated by. Example 1 25 parts by weight of commercially available melamine resin (Nica Resin S-260 manufactured by Nippon Carbide Industries Co., Ltd.), 25 parts by weight of novolac phenol resin, and 47 parts by weight of aluminum oxide with a new Mohs hardness of 12 and particle size #1000, and hexamine. 25 parts by weight of zinc stearate, 0.5 parts by weight of zinc stearate, and 0.2 parts by weight of benzoic acid were added, and the mixture was ground in a ball mill to obtain mold cleaning resin composition A. At this time, the K ₂₀ value of the flow hardening index was 0.35, and the K ₁₀ value was 0.13. Comparative Example 1 60 parts by weight of commercially available melamine resin (Nicaresin S-176 manufactured by Nippon Carbide Industries Co., Ltd.) and a new Mohs hardness of 7,
20 parts by weight of silica powder with particle size #200, 19 parts by weight of powder pulp, 0.3 parts by weight of phthalic anhydride, zinc stearate
A mold cleaning resin composition B was prepared by pulverizing 0.7 parts by weight using a ball mill. At this time, the K ₂₀ value of the flow hardening index was 0.26, and the K ₁ value was 0.13. The test results are shown in Table-1 and Table-2. Comparative Example 2 A phenolic resin was prepared by a known method using 105 parts by weight of phenol, 892 parts by weight of formalin (37% aqueous solution), and 3 parts by weight of caustic potash, dried under reduced pressure, and made into a powder. 12,
Resin composition C for mold cleaning was prepared by pulverizing 25 parts by weight of aluminum oxide having a particle size of #1500, 9 parts by weight of powder pulp, 0.4 parts by weight of ammonium chloride, and 0.5 parts by weight of zinc stearate in a ball mill. At this time, the K ₂₀ value of the flow hardening index was 0.23, and the K ₁₀ value was 0.15. The test results are shown in Table-1 and Table-2. Comparative Example 3 A mold cleaning resin composition D was prepared in the same manner as in Example 1 except that apatite powder with a new Mohs hardness of 5 and a particle size of #800 was used instead of silica powder in Example 1. The results are shown in Table-1 and Table-2. Comparative Example 4 A mold cleaning resin composition E was obtained in the same manner as in Example 1 except that 0.05 parts by weight of benzoic acid was used instead of 0.2 parts by weight. The _K20 value of the flow hardening index at this time is 0.16,
The _K10 value was 0.07. The test results of the cleaning effect using the obtained mold cleaning resin composition are shown in Tables 1 and 2. Comparative Example 5 A mold cleaning resin composition F was obtained in the same manner as in Example 1 except that 0.8 parts by weight of benzoic acid was used instead of 0.2 parts by weight. The _K20 value of the flow hardening index at this time is 0.99,
The _K10 value was 0.90. The cleaning effect test results using the obtained mold cleaning resin composition are shown in Tables 1 and 2.

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Claims (1)

[Claims] 1. A mold cleaning resin composition for removing dirt on the surface of a mold during molding of a curable resin molding material, the resin composition comprising the following (A) and (B), ( A) An amino resin made by mixing 2 to 150 parts by weight of a phenolic resin to 100 parts by weight of a melamine resin, and (B) A mineral powder having a new Mohs hardness of 6 to 15. , and the K ₂₀ value of the flow hardening index is 0.2
A mold cleaning resin composition having the above properties and a K ₁₀ value of 0.8 or less. 2. Claim 1, characterized in that the content of the mineral powder (B) is 10 to 90 parts by weight based on 100 parts by weight of the mold cleaning resin composition. Resin composition for mold cleaning. 3. The mold cleaning resin composition according to claim 1 or 2, wherein the mineral powder (B) has a particle size of #10 to #8000. 4. The mold cleaning resin composition according to any one of claims 1 to 3, wherein the curable resin molding material is an epoxy resin molding material.