JP2009102596A - Phenolic resin molding material and molded article using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic resin molding material reducing mold shrinkage factor and its anisotropy and also reducing linear expansion coefficient without deteriorating heat resistance and moldability which the phenolic resin molding material has, and to provide a molded article using the same. <P>SOLUTION: In the phenolic resin molding material in which a phenolic resin is blended with a filler, on the basis of the total amount, the phenolic resin is within a range of 8-20 mass% and fused silica as the filler is within a range of 78-90 mass%, and the fused silica consists of 100 mass%, in total, of (A) 85-95 mass% of fused silica having an average particle diameter within a range of 20-30 μm and (B) 5-15 mass% of fused silica having an average particle diameter within a range of 0.5-5 μm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a phenol resin molding material and a molded article using the same.

  Engineering plastics and epoxy resin materials are used as substitutes for metals and ceramics used in electrical and electronic parts and automotive parts, but they are heat resistant and dimensionally stable compared to parts obtained from metals and ceramics. In terms of sex, it is not close to that area yet.

  In recent years, particularly in the electronics field, miniaturization and high precision have been pursued, and the requirements for heat resistance and dimensional stability of molded products have become more severe.

  Phenolic resin molding materials (see Patent Documents 1 and 2) are excellent in heat resistance, and are expected as alternative materials for metals and ceramics, but have higher molding shrinkage, anisotropy, and linear expansion coefficient than metals and ceramics Therefore, improvement of dimensional accuracy has been a problem.

  The phenol resin undergoes a chemical change and physical change such as a curing reaction and cooling in the molding process, causes a volume change, and shrinks after molding. Further, since the volume change of the inorganic filler is much smaller than that of the resin, a large residual strain is generated after molding at the interface between the inorganic filler and the resin. In particular, when fiber-like or plate-like anisotropic inorganic fillers are used, the strain direction becomes non-uniform due to orientation during the flow of the phenol resin molding material, and depending on the direction due to molding shrinkage, moisture absorption, and dimensional changes after heat treatment A difference occurs, causing warping and distortion.

  Furthermore, since the degree of dimensional change varies depending on the shape and molding conditions of the molded product, it is difficult to obtain a product with stable dimensional accuracy.

  In addition, when metal is insert-molded, if the coefficient of linear expansion between the phenol resin molding material and the metal is different, cracks or interfacial peeling occurs in the molded product. In the phenol resin molding material, reinforcing fibers such as glass fibers are often used as reinforcing inorganic fillers to be blended with the phenol resin in order to improve heat resistance and dimensional stability. In addition, as a general technique for reducing the molding shrinkage rate and the linear expansion coefficient, high filling with inorganic fillers has been carried out. However, when inorganic fillers such as reinforcing fibers are highly filled into phenolic resin, Kneading stability and moldability are significantly impaired.

On the other hand, an epoxy resin material for semiconductor encapsulation that is highly filled with fused silica does not impair the kneading stability and moldability during production even when filled with fused silica, and does not impair molding shrinkage, its anisotropy, and linearity. It is possible to reduce the expansion coefficient.
JP-A 61-64755 JP 2005-79252 A

  However, the epoxy resin material for semiconductor encapsulation has low heat resistance compared to the phenol resin molding material, and needs to be refrigerated at 10 ° C. or lower.

  The present invention has been made in view of the circumstances as described above, and can reduce the molding shrinkage rate and its anisotropy without impairing the heat resistance and moldability of the phenol resin molding material. An object of the present invention is to provide a phenolic resin molding material capable of reducing an expansion coefficient and a molded product using the same.

  The present invention is characterized by the following in order to solve the above problems.

1stly, the phenol resin molding material of this invention is a phenol resin molding material which mix | blended the filler with the phenol resin, As a mixture ratio with respect to the whole quantity, phenol resin: 8-20 mass%, as a filler Fused silica: In the range of 78 to 90% by mass, the fused silica is in the total amount of 100% by mass of both of the following:
(A) 85-95 mass% of the thing in the range of 20-30 micrometers of average particle diameters,
(B) 5-15% by mass of an average particle size in the range of 0.5-5 μm,
It is characterized by the ratio of

  2ndly, in the said 1st phenol resin molding material, the mixture ratio of a phenol resin exists in the range of 10-18 mass%.

  Thirdly, in the first or second phenol resin molding material, the blending ratio of the phenol resin is composed of a novolac type phenol resin (P1) and a resol type phenol resin (P2), and its mass ratio (P1 / P2). ) Is in the range of 0.1-15.

  Fourth, the phenol resin molded product of the present invention is characterized in that any one of the first to third phenol resin molding materials is heat-press molded.

  According to the first aspect of the invention, the fused silica having a large average particle diameter and the fused silica having a smaller average particle diameter are used in combination and high filling is achieved. The molding shrinkage rate and its anisotropy can be reduced without impairing the properties and moldability, and the linear expansion coefficient can also be reduced. Therefore, the occurrence of warpage and strain is suppressed by reducing the molding shrinkage rate and its anisotropy, and even when metal is insert-molded by reducing the linear expansion coefficient, there is no occurrence of cracks or peeling of the interface. The change in moisture resistance can be reduced.

  According to the second aspect of the invention, by setting the blending ratio of the phenol resin to a specific range, in addition to the effect of the first aspect, the mold shrinkage rate, its anisotropy, and the linear expansion coefficient are further reduced. Can do.

  According to the third aspect of the invention, since the novolac type phenol resin and the resol type phenol resin are used at a specific ratio as the phenol resin, in addition to the effects of the first and second inventions, The anisotropy and linear expansion coefficient can be further reduced.

  According to the fourth aspect of the invention, since the material is formed by heating and pressure molding using the first to third phenol resin molding materials as raw materials, the heat resistance and moldability of the phenol resin molding material are impaired. In addition, the molding shrinkage rate and its anisotropy can be reduced, and the linear expansion coefficient can also be reduced. Therefore, the occurrence of warpage and strain is suppressed by reducing the molding shrinkage rate and its anisotropy, and even when metal is insert-molded by reducing the linear expansion coefficient, there is no occurrence of cracks or peeling of the interface. The change in moisture resistance can be reduced.

  Hereinafter, the present invention will be described in detail.

  Although there is no restriction | limiting in particular in the phenol resin used for this invention, Preferably what used the novolak type phenol resin and the resol type phenol resin together is used.

  The novolak-type phenol resin is obtained by condensing phenols and aldehydes in the presence of an acid catalyst, and there are no particular restrictions on the properties thereof, and novolaks that have been conventionally used in molding materials Type phenolic resin can be used.

  The resol type phenol resin includes a methylol type and a dimethylene ether type, and any of these may be used, and the resol type phenol resin may be liquid or solid.

  As for the compounding ratio of the novolac type phenol resin (P1) and the resol type phenol resin (P2), the mass ratio (P1 / P2) is preferably within the range of 0.1-15. By setting the mass ratio (P1 / P2) within the range, the molding shrinkage rate, its anisotropy, and the linear expansion coefficient can be further reduced.

  Although the weight average molecular weight of the phenol resin used by this invention does not have a restriction | limiting in particular, For example, it is 2000-4000.

  A phenol resin is 8-20 mass% with respect to the phenol resin molding material whole quantity, Preferably it is 10-18 mass%, More preferably, 12-16 mass% is contained. When the content of the phenol resin is less than 8% by mass, the kneading property is remarkably deteriorated and the moldability is lowered. On the other hand, when the content of the phenol resin exceeds 20% by mass, the molding shrinkage rate and the linear expansion coefficient increase, and the dimensional change with time after the moisture resistance treatment increases, so that it becomes impossible to obtain good dimensional accuracy.

  The fused silica as a filler used in the present invention is spherical and is contained within a range of 78 to 90% by mass with respect to the total amount of the phenol resin molding material, and with respect to the total amount of fused silica of 100% by mass, (A) The thing in the range of 20-30 micrometers of average particle diameter is contained in the ratio of 85-15 mass%, and the thing in the range of (B) average particle diameter of 0.5-5 micrometers is contained in the ratio of 5-15 mass%.

  When the content of the fused silica is less than 78% by mass, the molding shrinkage rate and the linear expansion coefficient increase due to the increase in the blending amount of the phenol resin, and the dimensional change with time after the moisture-resistant treatment increases. It becomes impossible to obtain dimensional accuracy. On the other hand, when the content of the fused silica exceeds 90% by mass, the kneading property is remarkably deteriorated and the moldability is lowered.

  Also, if the average particle size and content of the above two types of fused silica are outside the above ranges, it becomes difficult to highly fill the fused silica while ensuring good moldability, resulting in low molding shrinkage and low linear expansion. The coefficient cannot be obtained.

  The phenol resin molding material of the present invention may further contain other additives within the range not impairing the effects of the present invention. Specific examples of such additives include phenol resin curing agents and curing aids, release agents such as fatty acid metal salts, and pigments.

  Nitrogen compounds such as hexamethylenetetramine are preferably used as the curing agent for the novolak type phenol resin, and slaked lime is preferably used as the curing aid.

  The phenol resin molding material of the present invention can be prepared by kneading the above-mentioned phenol resin, fused silica, and other additives using a biaxial kneader or the like. After kneading, it may be cooled and pulverized and granulated.

The phenol resin molding material prepared in this way is made into a phenol resin molded product by heat and pressure molding by injection molding or the like. In the case of injection molding, the molding conditions can be, for example, a temperature of 150 to 190 ° C., a pressure of 88 to 137 MPa (900 to 1400 kgf / cm ² ), and a time of 20 seconds or more. In the case of other molding methods, molding can be performed according to these molding conditions.

  The phenolic resin molding material of the present invention requires parts having high heat resistance and high dimensional stability, such as a camera lens holding part of a mobile phone in which ceramics are mainly used, and high dimensional stability. It is suitable as a material for gas meter parts.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

  Each component shown in Table 1 was blended in a predetermined amount and mixed for 1 minute. Next, this mixture was kneaded at a temperature of 100 to 110 ° C. for 3 minutes with a twin-screw kneader. Thereafter, the kneaded product was cooled and pulverized and granulated to obtain phenol resin molding materials of Examples 1 to 7 and Comparative Examples 1 to 4.

The following ingredients were used as blending components.
[resin]
Novolac type phenolic resin: Matsushita Electric Works, Ltd. weight average molecular weight 2000-4000
Resol type phenolic resin: AX-10 Matsushita Electric Works, Ltd. Dimethylene ether weight average molecular weight 3000
Epoxy resin: ESCN195XL Cresol novolak type manufactured by Sumitomo Chemical Co., Ltd.
[Filler]
Fused silica (FB60 Denshi Kagaku Kogyo Co., Ltd., spherical average particle size 21.8 μm)
Fused silica (FB-3SDX Denki Kagaku Kogyo Co., Ltd. spherical average particle size 3.3 μm)
Glass beads (UB-01MF Unitika Ltd. low alkali borosilicate glass)
Wollastonite (Wollastonite NYAD400 manufactured by NYCO)
[Curing agent]
Hexamethylenetetramine (S-4, manufactured by Mitsui Toatsu Co., Ltd.)
Slaked Lime Diazabicycloundecene
[Release agent]
Zinc stearate (SZ-P manufactured by Sakai Chemical Industry Co., Ltd.)
Carnauba wax
[Pigment]
Carbon Black The following tests were conducted using the phenol resin molding materials of Examples 1 to 7 and Comparative Examples 1 to 4.
(1) Molding Shrinkage A test piece for molding shrinkage measurement was produced by injection molding (molding temperature 165 ° C., curing time 70 seconds) according to JIS K6911. The molding shrinkage rate was measured according to JIS K6911.
(2) Dimensional change in moisture resistance The test piece (90 mmφ) for measuring the mold shrinkage produced in (1) above was placed in a high-temperature and high-humidity tank of 40 ° C. × 90% for 250 hours, and the dimensional change rate relative to the initial dimensions was measured. .
(3) Linear expansion coefficient Using a target test piece-shaped mold (direct pressure molding), molding was performed under conditions of a mold temperature of 165 ° C., a pressure of 10 MPa, and a curing time of 180 seconds, and a test piece of φ5 mm × 15 mm Was made. Using this test piece, the linear expansion coefficient was measured by the TMA method.
(5) Glass transition temperature The glass transition temperature was measured by the TMA method.

  The test results are shown in Table 1.

  From Table 1, in Examples 1 to 7 in which fused silica having two kinds of specific average particle diameters as a filler is blended with a phenol resin, molding is performed as compared with Comparative Examples 1 and 3 using glass fibers as a filler. Shrinkage was reduced, and in particular, anisotropy was greatly reduced. Furthermore, the change in moisture resistance and the coefficient of linear expansion were also reduced. In addition, the molding shrinkage rate was significantly reduced as compared with Comparative Example 2 using glass beads as the filler, and the moisture resistance dimensional change and the linear expansion coefficient were also reduced. Moreover, compared with the comparative example 4 which mix | blended the epoxy resin as a resin material, the glass transition temperature was significantly high and it had high heat resistance.

Claims (4)

In the phenol resin molding material in which a filler is blended with a phenol resin, the blend ratio with respect to the total amount is within a range of phenol resin: 8 to 20% by mass, fused silica as a filler: 78 to 90% by mass, In the fused silica, the total amount of both of the following is 100% by mass,
(A) 85-95 mass% of the thing in the range of 20-30 micrometers of average particle diameters,
(B) 5-15% by mass of an average particle size in the range of 0.5-5 μm,
A phenolic resin molding material characterized in that   2. The phenol resin molding material according to claim 1, wherein a blending ratio of the phenol resin is within a range of 10 to 18% by mass.   The blending ratio of the phenol resin is composed of a novolac type phenol resin (P1) and a resol type phenol resin (P2), and the mass ratio (P1 / P2) is in the range of 0.1 to 15. The phenolic resin molding material according to claim 1 or 2.   A phenolic resin molded product, wherein the phenolic resin molding material according to any one of claims 1 to 3 is heat-pressed.