JP2015187229A - Phenolic resin molding material and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic resin molding material which keeps or improves a mechanical strength and reduces a shrinkage ratio at the time of molding, and thereby can obtain a molded product excellent in dimensional stability.SOLUTION: A phenolic resin molding material contains a bisphenol type phenolic resin and a filler. Preferably, the bisphenol type phenolic resin is obtained by using bisphenols at a rate of 50 mass% or more and 100 mass% or less based on the total monomer components. The molded product is obtained using these phenolic resin molding materials.

Description

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

  Phenolic resin molding materials are excellent in mechanical strength, heat resistance, dimensional stability, moldability, and the like, and have been used for a long time in key industries such as the automobile field and the electric / electronic field. Furthermore, in recent years, attempts have been actively made to replace metal parts made of iron or aluminum with phenolic resin molded articles for the purpose of cost reduction and weight reduction. There are many requirements in this process, but higher performance is desired especially for higher strength and improved molding dimensional accuracy.

  Here, as a problem of a molding material generally obtained using a thermosetting resin containing a phenol resin, there is a shrinkage generated during a curing reaction. This is due to the condensation reaction involving hexamethylenetetramine, which is generally used as a curing agent, or involving the methylol group in the resin during the curing reaction, resulting in the formation of a new chemical bond and three-dimensional crosslinking. This is because a portion that contracts with respect to the volume occupied by the phenolic resin is generated during the progress. Since this shrinkage reduces the molding dimensional accuracy, development for reducing the shrinkage rate is desired for the molding material.

  As an example of conventional studies for solving such a problem, a technique has been adopted in which a large amount of an inorganic filler is blended in a molding material and the ratio of the phenol resin is suppressed as much as possible (see, for example, Patent Document 1). ). However, when a large amount of inorganic filler is blended, the mechanical strength is greatly reduced, and there are many problems such as being unsuitable for weight reduction by increasing the density. In addition, there is a method for reducing the volatile component at the time of curing (see, for example, Patent Document 2), but since it is hardly involved in reducing the shrinkage reaction at the time of curing, a great effect cannot be expected. As described above, it has been difficult to stabilize the dimensional accuracy by realizing the reduction in the shrinkage rate while maintaining or improving the mechanical strength.

JP 2011-89095 A JP 05-148335 A

  The subject of this invention is providing the phenol resin molding material from which the molding excellent in dimensional stability is obtained by maintaining or improving mechanical strength and reducing the shrinkage rate at the time of shaping | molding.

Such an object is achieved by the following present invention [1] to [8].
[1] A phenol resin molding material comprising a bisphenol type phenol resin and a filler.
[2] The phenol resin molding material according to [1], containing the bisphenol type phenol resin in a proportion of 15% by mass or more and 60% by mass or less with respect to the entire phenol resin molding material.
[3] The phenol resin molding material according to [1] or [2], which contains the filler in a proportion of 30% by mass to 85% by mass with respect to the entire phenol resin molding material.
[4] The phenol resin according to any one of [1] to [3], wherein the bisphenol-type phenol resin is obtained by using, as a monomer, a bisphenol that is a compound having two hydroxyphenyl groups. Molding material.
[5] The bisphenol type phenolic resin is bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol. The phenol resin molding material according to any one of [1] to [4], which is obtained using at least one bisphenol selected from the group consisting of TMC and bisphenol Z as a monomer.
[6] The phenol resin molding according to [4] or [5], wherein the bisphenol-type phenol resin is obtained using the bisphenol in a proportion of 50% by mass or more and 100% by mass or less of the total monomer components. material.
[7] An inorganic base material selected from the group consisting of glass fiber, glass powder, silica fiber, and silica powder, and an organic base material selected from the group consisting of carbon fiber, carbon powder, and graphite powder. The phenolic resin molding material according to any one of [1] to [6], which contains one or more of the above.
[8] A molded product obtained by using the phenol resin molding material according to any one of [1] to [7].

  ADVANTAGE OF THE INVENTION According to this invention, the phenol resin molding material from which the molded article excellent in dimensional accuracy can be obtained by maintaining or improving mechanical strength and reducing the shrinkage rate at the time of shaping | molding.

  The phenol resin molding material of the present invention is characterized by containing a bisphenol type phenol resin and a filler. Thereby, the molded product excellent in dimensional accuracy can be obtained by maintaining or improving mechanical strength, and reducing the shrinkage rate at the time of shaping | molding. The molded product of the present invention is obtained using the above-mentioned phenol resin molding material. For this reason, it can be suitably used for various applications that require high strength and high dimensional accuracy. Hereinafter, embodiments of the present invention will be described in detail.

  First, the phenol resin molding material of the present invention will be described. The phenol resin molding material of the present invention contains a bisphenol type phenol resin and a filler. Thereby, the molded product excellent in dimensional accuracy can be obtained by maintaining or improving mechanical strength, and reducing the shrinkage rate at the time of shaping | molding.

The bisphenol type phenol resin used in the phenol resin molding material of the present invention may be either a novolac type or a resol type. The method for producing the novolac-type bisphenol-type phenol resin is not particularly limited, but bisphenols, which are compounds having two hydroxyphenyl groups, are used as essential monomer components, and phenols are used as monomers as required. Aldehydes for monomer components (M) consisting of bisphenols or bisphenols and phenols in the presence of an acidic catalyst such as oxalic acid, hydrochloric acid, sulfuric acid, toluenesulfonic acid, etc. A method in which the reaction molar ratio (F / M) of (F) is usually 0.5 or more and 0.9 or less is preferable. On the other hand, the method for producing a resol-type bisphenol-type phenol resin is not particularly limited, but bisphenols, which are compounds having two hydroxyphenyl groups, are used as essential monomer components, and phenols are used as necessary. In the presence of a basic catalyst such as lithium hydroxide, sodium hydroxide, magnesium hydroxide, barium hydroxide, calcium hydroxide, potassium hydroxide, ammonia, triethylamine, the monomer component added to the monomer component and aldehydes, A method in which the reaction molar ratio (F / M) of the aldehydes (F) to the monomer component (M) composed of bisphenols or bisphenols and phenols is usually 1.0 or more and 3.0 or less is preferable. . Here, the ratio of bisphenols in all monomer components is more preferably 50% by mass to 100% by mass, and particularly preferably 70% by mass to 100% by mass. Most preferably, 100% by mass is used. Thereby, mechanical strength and dimensional accuracy can be further improved.

  In the phenolic resin molding material of the present invention, by using a bisphenol type phenolic resin obtained by using bisphenols as an essential monomer component, the reason why the shrinkage rate during molding (curing shrinkage) can be reduced is not clear, For example, it can be considered as follows. First, the cause of the occurrence or increase of shrinkage in curing is that the microgel generated during the curing reaction forms a heterogeneous structure, and the structure shrinks to eliminate distortion caused by the heterogeneous structure. Conceivable. Accordingly, it is expected that shrinkage can be reduced by imparting uniformity of the cured product (molded product) so as not to generate distortion by controlling the curing reaction or the crosslinked structure. In this respect, the bisphenol type phenol resin obtained by using bisphenols as an essential monomer component has a structure in which the bonding of benzene rings derived from phenols is further suppressed, in other words, only phenols can be obtained as monomer components. It is presumed that by reducing the random structure of general phenolic resin as much as possible, the curing shrinkage can be reduced. More specifically, when bisphenols are used as an essential monomer component, bisphenols have a structure in which the para positions of the phenol skeleton are pre-bonded, so the reaction point with aldehydes is only the ortho position. Becomes active, and the structure is easily made uniform. As a result, a resin structure with high orientation can be obtained while being three-dimensionally cross-linked, and it is assumed that distortion during curing is less likely to occur and curing shrinkage can be reduced. In addition, it is presumed that the mechanical strength can be improved because the three-dimensional cross-linking is uniformly performed.

  The bisphenols used in the production of the bisphenol type phenol resin are not particularly limited as long as they are compounds having two hydroxyphenyl groups. For example, bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol TMC, bisphenol Z and the like can be mentioned. May be used in combination. Among these, bisphenol A or bisphenol F is preferable in view of the low steric hindrance at the site to which phenol is bonded, in which the reactivity with aldehydes decreases and the economy in raw material prices.

  The phenols used for the production of the bisphenol type phenol resin are not particularly limited. For example, phenol, orthocresol, metacresol, paracresol, xylenol, para tertiary butylphenol, paraoctylphenol, paraphenylphenol. And phenols such as resorcin, and usually phenol and cresol. These may be used alone or in combination of two or more.

  The aldehydes used in the production of the bisphenol type phenol resin are not particularly limited, and examples thereof include aldehydes such as formaldehyde, acetaldehyde, butyraldehyde, acrolein, and mixtures thereof. Substances that are the source of aldehydes, or solutions of these aldehydes can be used, but usually formaldehyde is often used.

As described above, as a method for producing a bisphenol-type phenol resin, a bisphenol is used as an essential monomer component, and if necessary, a monomer component obtained by adding phenols to the monomer component and formaldehyde are acidic or basic. A method of reacting under a catalyst is preferable, but other methods, for example, a resin synthesized by reacting a monomer component consisting only of bisphenols with formaldehyde under an acidic or basic catalyst, and only from phenols A general random type phenol resin synthesized by reacting a monomer component and formaldehyde in the presence of an acidic or basic catalyst, dissolved in an organic solvent and stirred and mixed, or a pressure kneader, roll Also by a melt kneading method with a single screw or twin screw kneader Rukoto can.

  In the phenol resin molding material of the present invention, the content of the bisphenol-type phenol resin with respect to the entire molding material is not particularly limited, but it is preferably a ratio of 15% by mass or more and 60% by mass or less, It is more preferable that the ratio is not less than 50% by mass and not more than 50% by mass. By making it within the above range, the effect of the present invention can be obtained more reliably. Moreover, by setting it as the said lower limit or more, there is little possibility that formation of molding materials, such as kneading | mixing, will become difficult, or workability | operativity in a molding material stage will fall. Moreover, by setting it as the said upper limit or less, there is little possibility that the mechanical strength of a molded product falls or a dimensional accuracy falls.

  The filler used in the phenolic resin molding material of the present invention is not particularly limited. For example, wood powder, coconut powder, fir shell powder, corn powder, plywood powder, resin molded product powder, pulp powder, Organic powder fillers such as carbon powder and graphite powder; silica, alumina, magnesia, zirconia, carbon, silicon carbide, boron nitride, aluminum nitride, silicon nitride, calcium carbonate, calcium carbonate, barium carbonate, barium sulfate, calcium sulfate, clay , Talc, mica, calcium hydroxide, aluminum hydroxide, wollastonite, inorganic powder fillers such as metal powder; glass fiber, carbon fiber, silicon carbide fiber, alumina fiber, Tyranno fiber, basalt fiber (basalt / rock wool) , Inorganic fibers such as kaolin wool and ceramic fibers; aramid fibers, knitted fabrics, Help, polyethylene fibers, organic fibers such as polyparaphenylene benzoxazole (PBO) fibers; stainless steel fibers, metal fibers steel fibers, other, boron fibers, natural fibers, reinforcing fibers natural fibers or the like modified. The above fillers may be used alone or in combination of two or more. In view of the stability of dimensional accuracy, it is particularly preferable to use an inorganic powder filler such as glass powder or silica powder. From the viewpoint of mechanical strength, it is particularly preferable to use a fiber substrate such as glass fiber, silica fiber, or carbon fiber. Furthermore, from the viewpoint of heat dissipation, fillers with high thermal conductivity such as carbon powder and graphite powder are particularly preferable.

  The glass powder used in the present invention is in the form of beads or powders, and there are many types of compositions, shapes, particle sizes, etc., which are preferable in terms of wide selectivity depending on the purpose of use. In particular, in the case of spherical glass beads, there is no orientation during flow during molding, molding shrinkage and post-shrinkage are uniform, and good dimensional accuracy and dimensional stability can be ensured.

  In the phenolic resin molding material of the present invention, the content of the filler relative to the entire molding material is not particularly limited, but is preferably a ratio of 30% by mass or more and 85% by mass or less, and 40% by mass. The ratio is more preferably 75% by mass or less. By making it within the above range, the effect of the present invention can be obtained more reliably. Moreover, by setting it as the said lower limit or more, there is little possibility that the mechanical strength of a molded product falls or a dimensional accuracy falls. Moreover, by making it into the said upper limit or less, there is little possibility that formation of molding materials, such as kneading | mixing, will become difficult, or workability | operativity in the molding material stage will fall.

  In the phenol resin molding material of the present invention, a colorant, a release agent, a conductive agent, a coupling agent, a curing aid, a solvent, and the like are blended according to the purpose and application within a range not impairing the effects of the present invention. Can do.

  The method for producing the phenol resin molding material of the present invention is not particularly limited. For example, after mixing the above-described raw materials in a mixer or the like, a kneading machine such as a two-roll, a kneader, or a twin-screw extruder is used. It can be obtained by kneading alone or in plural. The material temperature at the time of kneading, kneading conditions such as the kneading time are not particularly limited, and vary depending on the type and content of the resin, the type and content of the filler, etc. The kneading time is, for example, about 30 seconds to 30 minutes, preferably about 1 to 20 minutes.

  Next, the molded product of the present invention will be described. The molded product of the present invention is obtained by using the above-described phenol resin molding material of the present invention. Although it does not specifically limit as a shaping | molding method for obtaining the molding of this invention, It can shape | mold by shaping | molding methods, such as transfer shaping | molding, compression shaping | molding, and injection shaping | molding. Molding conditions such as molding temperature and molding time (curing time) are not particularly limited and vary depending on the thickness of the molded product and the molding method, but the molding temperature is, for example, about 150 to 200 ° C., The temperature is preferably about 160 to 190 ° C., and the curing time is, for example, about 20 seconds to 10 minutes, preferably about 30 seconds to 5 minutes. Further, the molded product of the present invention may be subjected to after baking (post-curing treatment) depending on the purpose and application as long as the effects of the present invention are not impaired. The after-baking conditions are not particularly limited and vary depending on the purpose and application, but the processing temperature is, for example, about 120 to 300 ° C., preferably about 150 to 250 ° C., and the processing time is as follows: For example, it is about 30 minutes to 24 hours, preferably about 1 to 12 hours.

  Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. Experimental examples employed in the examples and comparative examples are experimental examples for confirming the effects of the present invention. It is not limited to only examples. In the following description, “part” means “part by mass”.

The phenol resins used in Examples and Comparative Examples are as follows.
(Synthesis Example 1)
In a reactor equipped with a stirrer, a temperature controller, a thermometer, and a cooling condenser, 1000 parts of bisphenol F, 90 parts of a 50% formaldehyde aqueous solution and 1 part of oxalic acid were added and reacted at 100 ° C. for 3 hours. The temperature was raised to 0 ° C. under vacuum to obtain 950 parts of a bisphenol type phenol resin A (number average molecular weight: 800).

(Synthesis Example 2)
950 parts of bisphenol type phenol resin B (number average molecular weight 800) was obtained under the same synthesis conditions as in Synthesis 1 except that 800 parts of bisphenol F, 200 parts of phenol, and 110 parts of 50% formaldehyde aqueous solution were used.

(Synthesis Example 3)
Under the same synthesis conditions as in Synthesis 1 except that 1000 parts of bisphenol A and 79 parts of 50% formaldehyde aqueous solution were used, 950 parts of bisphenol type phenol resin C (number average molecular weight 800) was obtained.
(Synthesis Example 4)
Under the same synthesis conditions as in Synthesis 1 except that 600 parts of bisphenol F, 400 parts of phenol, and 131 parts of 50% formaldehyde aqueous solution were used, 950 parts of a bisphenol type phenol resin (number average molecular weight 800) was obtained.

For comparison, a general random type phenol resin obtained by using only phenol as a monomer component (manufactured by Sumitomo Bakelite Co., Ltd., trade name: PR-51714, number average molecular weight:
800) was used.

The raw materials other than the above used in Examples and Comparative Examples are as follows.
Hardener: Hexamethylenetetramine Glass beads: manufactured by Unitika Ltd., trade name UNIBEADS UB-13L
Mold release agent: calcium stearate

(Examples 1-6, Comparative Example 1)
The bisphenol type phenol resins A, B, C, D and the random type phenol resin prepared in Synthesis Examples 1 to 4 were dry blended with the raw materials shown in Table 1 at the ratio shown in Table 1, and then subjected to 90 using a lab plast mill. A molding material was obtained by melt-kneading at a temperature of 10 ° C. for 10 minutes, pulverizing after cooling.

  About the obtained molding material, the test piece was produced with the transfer molding machine using the metal mold | die of 175 degreeC, and the performance of the obtained molded article was measured. The results are shown in Table 1. The molding conditions for preparing the test piece were a molding temperature of 175 ° C. and a curing time of 3 minutes. Moreover, about various characteristic evaluation, it measured according to JISK6911 standard.

  From Table 1, it was clarified that the mechanical strength was improved and the molding shrinkage ratio was reduced in the case of using the bisphenol type phenol resin than in the case of using the random type phenol resin (Examples). 1, 2, 3, 4, 5, 6, Comparative Example 1).

The phenolic resin molding material of the present invention is capable of obtaining a molded product with improved mechanical strength and dimensional accuracy, and is a metal structural component or mechanical component in a key industry field such as the automobile field or the electric / electronic field. It is possible to greatly promote the replacement of resin.

Claims (8)

  A phenolic resin molding material comprising a bisphenol type phenolic resin and a filler.   2. The phenol resin molding material according to claim 1, wherein the phenol resin molding material contains the bisphenol type phenol resin in a ratio of 15% by mass or more and 60% by mass or less with respect to the entire phenol resin molding material.   The phenol resin molding material of Claim 1 or 2 which contains the said filler in the ratio of 30 to 85 mass% with respect to the said phenol resin molding material whole.   The phenol resin molding material according to any one of claims 1 to 3, wherein the bisphenol-type phenol resin is obtained by using, as a monomer, a bisphenol that is a compound having two hydroxyphenyl groups.   The bisphenol type phenol resin is bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol TMC, and The phenol resin molding material according to any one of claims 1 to 4, which is obtained using one or more bisphenols selected from the group consisting of bisphenol Z as a monomer.   The phenol resin molding material according to claim 4 or 5, wherein the bisphenol-type phenol resin is obtained by using the bisphenol at a ratio of 50% by mass or more and 100% by mass or less of the total monomer components.   The filler is one kind of an inorganic base material selected from the group consisting of glass fiber, glass powder, silica fiber, and silica powder, and an organic base material selected from the group consisting of carbon fiber, carbon powder, and graphite powder. The phenol resin molding material as described in any one of Claim 1 to 6 included above. A molded product obtained by using the phenol resin molding material according to any one of claims 1 to 7.