JPH0710630A - Molding material, its production and molded article thereof - Google Patents

Abstract

PURPOSE:To obtain a molding material for supplying a molded article having high strength and modulus of elasticity, excellent water resistance and heat resistance. CONSTITUTION:A molding material comprises a composition composed of a formaldehyde-based resin precursor which does not substantially contain water but forms water by curing reaction, a hydraulic cement and optionally an additive and/or a filler. This molding material is molded, heated and cured to give a high-strength molded article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding material having high strength and elastic modulus, and excellent in water resistance and heat resistance, a method for producing the same, and a molded article thereof.

[0002]

2. Description of the Related Art Formaldehyde resins are molding materials,
Widely used in adhesives and laminated products. Of these, the molding material is obtained by mixing a formaldehyde resin precursor with a filler such as wood powder, pulp, diatomaceous earth, a curing agent, a lubricant, a colorant, pulverizing and classifying the mixture, and then improving the fragility and bending strength. In order to improve, it is manufactured by using cotton, hemp, glass fiber or the like as a filling material. Such molding materials are subjected to compression molding, transfer molding, injection molding, etc. to produce molded products, but the bending strength when fibrous materials such as glass fiber and hemp are not used as a filler is 50 to 10
It is about 0 N / mm ² .

On the other hand, hydraulic cement is usually used as a mixture with 25% or more of the weight of water, and an aggregate obtained by adding aggregate is widely applied to the field of civil engineering and construction as mortar or concrete. . A hardened product using this hydraulic cement has high compressive strength but low flexural strength.
Since it is about 0 N / mm ^2, it is generally used by being reinforced with reinforcing bars and fibers.

[0004] The strength of the hardened material using hydraulic cement increases as the amount of water when mixed is smaller and the number of pores contained in the hardened material is smaller. As an example thereof, a hardened cement product having extremely high flexural strength without the need for fibers or high compression molding is known (Japanese Patent Publication No. 59-4343).
No. 1, etc.). This hardened product is made by mixing hydraulic cement, water and aqueous organic polymer with high shearing force such as a two roll mill to reduce the amount of added water and to limit the size and proportion of pores in the hardened product. High strength is obtained.

[0005]

However, the bending strength of the molding material using the formaldehyde resin is
100 N / mm ² when the fiber material is not used as the filling material
It cannot be expected that the strength will exceed the above. Therefore, if the fibers are mixed, the fibers will be broken during the production of the molding material, and the fibers will be oriented during the molding, and variations in strength and directionality will appear. Further, when fibers are mixed, the fluidity is lowered, so that there are problems that the material does not spread to the details of the mold and the smoothness of the surface is lost.

[0006] The hardened cement product invented in Japanese Patent Publication No. 59-43431, etc. has a small amount of water when mixed, which is about 7 to 30% of the hydraulic cement, and gives an extremely high bending strength. Since it contains coalesce, there is a problem in that it has poor water resistance such as a significant decrease in strength and swelling when immersed in water. In order to improve this water resistance, there is an example in which an isocyanate compound is reacted with a hydrophilic group (JP-A-63-206342), but the isocyanate compound has a strong irritating odor and is toxic. However, there are problems in the work of mixing and molding, and the urethane derivative, which is the main reaction product, has low heat resistance.

[0007]

Therefore, according to the present invention,
The purpose of the present invention is to provide a molding material having high strength and elastic modulus, excellent in water resistance and heat resistance, and a molded article thereof, the gist of which is a formaldehyde resin precursor and hydraulic cement, and According to the above, a composition containing an additive and / or a filler is mixed substantially without adding water, and the molded product has a fiber material of 50 N / mm ² , Sometimes 10
It has been found that a bending strength exceeding 0 N / mm ² is exhibited.

The present invention will be described in detail below. The formaldehyde resin precursor used is substantially water-free and used in the absence of water. (Potentially having water), and examples thereof include a phenol resin precursor, a melamine resin precursor, and a urea resin precursor.

The term "substantially free of water" as used in the present invention means that the water content of the precursor is 5% or less, more preferably 4% or less, and most preferably 2% with respect to the weight of the hydraulic cement. It is the following. This water content is, for example, the Karl Fischer method (Analytical Chemistry Handbook, edited by Japan Society for Analytical Chemistry, 1
971, according to pages 31 and 32).
If the water content exceeds 5%, the hydraulic cement hardens or weathers during the production or storage of the molding material, or the strength of the molded article decreases, which is not preferable.

As the hydraulic cement, a conventional cement can be used. Examples thereof include Portland cement (eg, normal Portland cement, early-strength Portland cement, moderate heat Portland cement, etc.), mixed cement (eg, blast furnace cement, silica cement, fly ash cement, etc.), special cement (eg, alumina cement, oil well cement). Etc.) and various plasters. The hydraulic cement may be used alone, or two or more of the above cements may be mixed and used. Commercially available products of these hydraulic cements can be used as they are, but adjusting the particle size distribution of the particles of the hydraulic cement in multiple modes or rounding the particle shape improves the strength and fluidity of the molding material. Is effective for.

The blending ratio of the formaldehyde resin precursor in the present invention may be determined depending on the moldability and the performance of the molded product, and generally 5 to 100 parts by weight of the precursor is based on 100 parts by weight of the hydraulic cement. Is more preferable, and more preferably 7 to 60 parts by weight (at this time, alcohols are not included). When the precursor is less than 5 parts by weight,
The mixing state of each component and the fluidity of the molding material are poor, and defects are likely to occur in the molded product. On the other hand, if the amount is more than 100 parts by weight, the molded article tends to crack and the strength tends to reach a peak or decrease, which is not economically preferable.

In the molding material of the present invention, a polymer having an acid amide bond, such as polyamide or polyacrylamide, is preferably used as an additive for modifying the performance of the molded product. The blending ratio is generally 0. 0 with respect to 100 parts by weight of the formaldehyde resin precursor.
It is preferably 5 to 30 parts by weight, more preferably 2 to 20 parts by weight. 0.
If it is less than 5 parts by weight, the effect is not obtained, and if it exceeds 30 parts by weight, the modifying effect is not large and it is uneconomical.

It is preferable that these additives be finely pulverized in advance before mixing. Furthermore, when mixing using alcohols, it is more preferable that the polyamide is alcohol-soluble. In this alcohol-soluble polyamide, at least a part of hydrogen of amide bond -CONH- is replaced with a methoxymethyl group, or amide bond -CON generated from a secondary amine.
Some have (R)-.

In addition to the above additives, known lubricants, silane coupling agents, colorants and the like can be used as additives in the molding material of the present invention. For example, as a lubricant, glycerol, glycerol triacetate, phthalic anhydride, furfural, alkylphenol, zinc stearate, magnesium stearate, rosin, etc., and as a silane coupling agent, γ-aminopropyltriethoxysilane, γ-ureidopropyltrisane. Examples include ethoxysilane and γ-glycidoxypropyltrimethoxysilane. Colorants include organic and inorganic pigments such as aniline black, carbon black and titanium oxide.

As the filler according to the present invention, wood powder, pulp, cotton floc, stone powder, ground calcium carbonate,
Conventional materials such as aluminum hydroxide, sand, lightweight aggregate, glass fiber and carbon fiber can be used. When these fillers are used, it is preferable to increase the mixing ratio of the precursor according to the amount used.

Next, a method of manufacturing the molding material according to the present invention will be described. The above-mentioned formaldehyde resin precursor and hydraulic cement, and a composition containing an additive as required are mixed so that the respective components are uniformly dispersed,
Obtain a molding material. For mixing mortar mixer, kneader,
It can be carried out using a conventional mixer such as a blender or a roll, but it is desirable to select an appropriate mixer depending on the blending ratio of each component, the mixing method shown below, and the like.

First, in the powder state mixing, the components are mixed with each other at room temperature using a conventional mixer such as a kneader, a mortar mixer and a blender. In this case, it is effective to finely pulverize and use each component, or to add a small amount of a solvent such as methanol or ethanol to prevent each component from scattering. The powdery mixture is dried if necessary to obtain a molding material.

Secondly, in the mixing of the formaldehyde resin precursor in a molten state by heat, each component is heat mixed by using a mixer such as a Banbury mixer, a kneader or a heat roll heated by steam or an electric heater. To be done. This hot mixing temperature needs to be in a temperature range in which the precursor is sufficiently melted but the methyleneation reaction does not significantly proceed, and is generally in the range of 80 to 150 ° C. If the temperature at the time of hot mixing exceeds 150 ° C., the curing reaction of the precursor will proceed excessively before being sufficiently mixed, so that it is not preferable that the temperature of the hot mixing is too high.

Then, the mixture after hot mixing is dried, if necessary, and then pulverized and classified to obtain a molding material.
Further, depending on the molding method and the shape of the product in the subsequent manufacturing of the molded product, the product obtained by heat mixing can be used as the molding material without undergoing the pulverizing and classifying steps.

Thirdly, when the formaldehyde resin precursor is mixed in an alcohol solution, the respective components are mixed by using a mixer such as a kneader, a Banbury mixer, a mortar mixer or a two roll mill. Generally, this mixing is performed at room temperature, but if each component can be sufficiently dispersed,
In order to accelerate the evaporation of the alcohols, they may be heated to around the boiling point of the alcohols and mixed.

The formaldehyde resin precursor used for this mixing is soluble in alcohol and is used in a state of being dissolved in alcohol beforehand. The amount of alcohols is determined in consideration of the dispersion effect of each component and the subsequent moldability,
Generally, an alcohol solution having a nonvolatile content of 20 to 80% is preferable. As the alcohol in the present invention, a wide range of alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol, phenol, cresol, ethylene glycol and trimethylene glycol can be used.

The mixture after the mixing is dried to evaporate the alcohol, if necessary, and then pulverized,
A molding material is obtained by classification. In addition, depending on the molding method and product shape in the subsequent manufacturing of a molded product, a paste-like or dough-like mixture can be used as a molding material without being dried, crushed and classified after mixing.

The molding material obtained as described above is subjected to compression molding, transfer molding, injection molding, extrusion molding, cast molding and the like, and is subjected to heat treatment during molding and / or after molding to obtain a molded product. The heating temperature is 100-30
The range of 0 ° C., preferably 150 to 250 ° C. is good. It is considered that the heating cures the formaldehyde-based resin precursor, and at the same time, the water produced by the curing causes the hydraulic cement to undergo a hydration reaction to provide high strength. It is also considered that aluminum ions are ionically cross-linked with the resin due to the presence of a small amount of generated water as a reason for the high strength.

The molded article according to the present invention can be used as it is for various purposes, but in order to further enhance its appearance,
It can also be used by coating with a synthetic resin paint or lacquer. The use of the molded article according to the present invention includes a body,
Automobile / transport equipment related fields such as ship parts and pallets,
Electronic / electrical related fields such as equipment housings, insulation parts, IC encapsulation materials, parabolic antennas, concrete reinforcements, concrete formwork, water tanks, roof materials, civil engineering / construction related fields such as inner wall materials, tanks, pipes, etc. It can be widely applied to the chemical industry related fields, general machinery related fields such as gears and gears.

[0025]

[Examples] Examples of the present invention will be described below, in which the molding material of the present invention has high strength and elastic modulus, water resistance,
It is revealed that it has excellent heat resistance.

[Examples 1 and 2] As shown in Table 1, alumina cement (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Denka Alumina Cement No. 1), phenol resin precursor (manufactured by Showa Polymer Co., Ltd., Product name Shonor BRG-558),
Hexamethylenetetramine, zinc stearate, furfural, and a colorant (trade name, Bayer Titanium, manufactured by Bayer Japan KK) were mixed and mixed using a rubber roll machine heated to 110 ° C. by steam. The roll rotation ratio at this time was set to 1: 1.3. The water content of the phenol resin precursor measured by the Karl Fischer method was 0.1%. The dough-like mixture wound on the roll was peeled off by this mixing, and then the mixture was crushed in a stainless mortar to prepare a molding material. This molding material was packed in a mold kept at a temperature of 120 ° C., and 10 N / mm ²
Then, the temperature of the mold was raised to 180 ° C., and the temperature was maintained for 6 hours to produce a sheet-shaped molded product having a thickness of about 3 mm.

The molded product was cut into a piece having a width of 15 mm and a length of 80 mm to prepare 10 test pieces. Five of them were immediately subjected to a bending test, and the remaining five were soaked in water at 20 ° C. for 7 days and then subjected to a bending test. The bending test was carried out by bisector loading with the distance between fulcrums set to 60 mm.
At the same time, the deflection of the central portion of the test body was measured to calculate the bending elastic modulus. The results obtained are shown in Table 1.

[0028]

[Table 1]

[Example 3] Alumina cement (produced by Denki Kagaku Kogyo KK, trade name Denka Alumina Cement No. 1),
Phenol resin precursor (Showa High Polymer Co., Ltd., trade name Shonor BKM-2620) crushed in a stainless mortar and zinc stearate were mixed with a mortar mixer.
The powder was mixed for 1 minute to prepare a molding material. In addition,
The water content of the phenol resin precursor measured by the Karl Fischer method was 4.5%. This molding material
In the same manner as in Examples 1 and 2, a test body was formed by molding and a bending test was performed. The results obtained are shown in Table 1.

[Examples 4 to 7] As shown in Table 2, ordinary Portland cement, alumina cement (produced by Denki Kagaku Kogyo KK, trade name Denka Alumina Cement No. 1), alcohol solution of phenol resin precursor (Showa era) High Polymer Co., Ltd., trade name Shonor BRS-330, non-volatile content 60.6%, water content 1.3%), N-methoxymethylated polyamide (30% substitution of amide bond hydrogen with methoxymethyl group) Teikoku Kagaku Sangyo Co., Ltd., trade name Toresin), glycerol and a silane coupling agent (Shin-Etsu Chemical Co., Ltd., trade name KBE-903) were mixed and premixed for 2 minutes with a mortar mixer, and then paired. The mixture was mixed for 4 minutes with a rubber roll machine with the roll rotation ratio set to 1: 1.2. The dough-shaped mixture wound around the roll by this mixing was taken out into a sheet of about 2 mm to prepare a molding material. This molding material was compression-molded with a mold having a temperature of 80 ° C. at a compression stress of 6 N / mm ² , and then heat-treated at 200 ° C. for 15 hours to produce a sheet-shaped molded product.

The molded product has a width of 25 mm and a length of 100 mm.
It was cut out into 10 pieces to prepare 10 test pieces, and the same test as in Examples 1 and 2 was performed. The obtained results are shown in Table 2. Further, the molded product after the test was made into a fine powder and subjected to X-ray diffraction, but no peak of cement hydrate that could be identified by X-ray diffraction was observed.

[0032]

[Table 2]

[Examples 8 to 11] In addition to the materials of Example 5, an alcohol solution of a melamine resin precursor as a formaldehyde resin precursor (manufactured by Mitsui Toatsu Chemicals, Inc., nonvolatile content: 74.6%, water content) The amount was 4.3%), and polyacrylamide was used as an additive. The materials were pre-mixed for 2 minutes on a tabletop kneader and then mixed for 4 minutes on a rubber roll machine with a pair of roll rotation ratios set to 1: 1.2. The dough-shaped mixture wound on the roll by this mixing was taken out into a sheet of about 3 mm to prepare a molding material. After passing the molding material several times between rolls having a rotation ratio of 1: 1 and rolling and molding to about 1.5 mm,
Heat treatment was carried out at 200 ° C. for 15 hours to produce a sheet-shaped molded product.

The molded product has a width of 25 mm and a length of 100 mm.
It was cut out into 10 pieces to prepare 10 test pieces, and the same test as in Examples 1 and 2 was performed. The results obtained are shown in Table 3.

[0035]

[Table 3]

Example 12 and Comparative Example In order to evaluate the heat resistance of the molded product, the molded product obtained by the same operation as in Example 9 was heated at 300 ° C. for 6 hours, and then the bending strength was measured.
For comparison, a commercially available product of Company A having a high bending strength and a thickness of about 4 mm was cut into a width of 25 mm and a length of 75 mm, heated at the same temperature, and then the bending strength was measured. The strengths before and after heating are shown in Table 4.

[0037]

[Table 4]

Claims (24)

[Claims] 1. A composition containing a formaldehyde-based resin precursor and a hydraulic cement, which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. Molding material consisting of. 2. A powder containing a composition containing a formaldehyde-based resin precursor and a hydraulic cement which are substantially free of water but produce water upon curing, and optionally an additive and / or a filler. A molding material obtained by mixing in the state of. 3. A composition containing a formaldehyde-based resin precursor and a hydraulic cement that does not substantially contain water but produces water upon curing, and a composition containing an additive and / or a filler, if necessary, by heat. A molding material obtained by mixing the precursor in a molten state. 4. A composition containing a formaldehyde-based resin precursor and a hydraulic cement that does not substantially contain water but produces water upon curing, and a composition containing an additive and / or a filler, if necessary, by heat. A molding material obtained by mixing the precursor in a molten state, and then pulverizing and classifying the obtained material. 5. A composition containing a formaldehyde resin precursor and a hydraulic cement which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. A molding material in which the body is mixed in an alcohol solution. 6. A composition containing a formaldehyde resin precursor and a hydraulic cement which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. A molding material obtained by crushing and classifying the product obtained by mixing the body in the state of an alcohol solution and then evaporating the alcohol. 7. The molding material according to claim 1, wherein the formaldehyde resin precursor is a phenol resin precursor. 8. The molding material according to claim 1, wherein the formaldehyde resin precursor is a melamine resin precursor. 9. The molding material according to claim 1, wherein the formaldehyde resin precursor is a urea resin precursor. 10. The molding material according to claim 1, wherein the additive is a polymer having an acid amide bond. 11. The molding material according to claim 1, wherein the additive is polyamide. 12. The molding material according to claim 1, wherein the additive is an aliphatic alcohol-soluble polyamide. 13. The molding material according to claim 1, wherein the additive is polyacrylamide. 14. A powder containing a composition containing a formaldehyde resin precursor and a hydraulic cement which are substantially free of water but generate water upon curing, and optionally an additive and / or a filler. The method for producing a molding material obtained by mixing in the state of. 15. A composition containing a formaldehyde-based resin precursor and a hydraulic cement that does not substantially contain water but produces water upon curing, and a composition containing an additive and / or a filler, if necessary, by heat. A method for producing a molding material obtained by mixing the precursor in a molten state. 16. A composition containing a formaldehyde-based resin precursor and a hydraulic cement, which are substantially free of water but produce water upon curing, and a composition containing an additive and / or a filler, if necessary, by heat. A method for producing a molding material obtained by mixing the precursor in a molten state, and then pulverizing and classifying the obtained material. 17. A precursor containing a formaldehyde resin precursor and a hydraulic cement which are substantially free of water but produce water upon curing, and a composition containing an additive and / or a filler if necessary. A method for producing a molding material obtained by mixing a body in an alcohol solution. 18. A composition containing a formaldehyde-based resin precursor and a hydraulic cement, which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. A method for producing a molding material, which is obtained by mixing a body in an alcohol solution state, then evaporating alcohol and crushing and classifying the obtained material. 19. A mixture of a formaldehyde-based resin precursor and a hydraulic cement, which is substantially free of water but produces water upon curing, and a composition containing an additive and / or a filler if necessary. A molded product obtained by molding, heat treating, and curing the following molding material. 20. A powder containing a composition containing a formaldehyde resin precursor and a hydraulic cement, which are substantially free of water but generate water upon curing, and optionally an additive and / or a filler. A molded product obtained by molding, heating and curing a molding material that is mixed in the state. 21. A composition containing a formaldehyde-based resin precursor and a hydraulic cement, which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler, if necessary, is heated. A molded article obtained by molding, heating and curing a molding material obtained by mixing the precursors in a molten state. 22. A composition containing a formaldehyde-based resin precursor and a hydraulic cement that does not substantially contain water but produces water upon curing, and optionally a composition containing an additive and / or a filler is heated. A molded product obtained by mixing the precursor in a molten state, crushing the obtained product, and classifying the obtained molding material, followed by heat treatment to cure the molding material. 23. A precursor containing a formaldehyde-based resin precursor and a hydraulic cement which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. A molded product obtained by molding, heat treating and hardening a molding material composed of a body mixed in an alcohol solution. 24. A composition containing a formaldehyde-based resin precursor and a hydraulic cement which are substantially free of water but generate water upon curing, and a composition containing an additive and / or a filler if necessary. A molded product obtained by molding, heating and curing a molding material obtained by crushing and classifying the product obtained by mixing the body in the state of an alcohol solution and then evaporating the alcohol.