JP3204960B2 - Melamine resin molding material composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides excellent heat fluidity during molding, and
Melamine-based resin molding material composition having excellent appearance and extremely excellent crack resistance and impact resistance in a molded article, particularly, the composition is preferably a granular molding material composition in terms of automatic metering suitability and the like. The present invention also relates to a melamine-based resin molding material composition which is extremely excellent in suitability for forming a preheated tablet, suitability for preventing dusting, and collapse resistance, in addition to having less occurrence of spots on the surface of the molded product even when the molding is performed. Specifically, a heat-extruded product of (A) a melamine-based resin molding material pre-dried product, (B) a powdered melamine-based resin, and (C) a melamine-based resin molding material powder containing a specific amount of powder pulp is used. It relates to a melamine-based resin molding material composition characterized by being re-crushed.

[Conventional technology]

Melamine-based resin molding materials have been conventionally produced by a so-called wet method or dry method.

To produce a melamine resin molding material by a wet method, a formaldehyde such as formalin or paraformaldehyde and a melamine and, if necessary, a co-condensation component such as urea, benzoguanamine or phenol are subjected to a condensation reaction in a solution to form a syrup-like initial material. A condensate is obtained, which is impregnated with a filler such as pulp and wood flour, and then dried to form a popcorn,
Next, this is pulverized and colored, and further granulated as necessary to obtain a melamine resin molding material.

Further, in order to produce a melamine resin molding material by a dry method, the syrup-shaped melamine resin precondensate obtained above is dried by a spray drying method or the like into a powdery resin,
Fillers, pigments and other additives are dry-mixed with the powdered resin, and if necessary, granulated to obtain a melamine resin molding material.

However, the melamine-based resin molding material obtained by the wet method is not sufficient in terms of the crack resistance and impact resistance of the molded product. However, there is a problem that the heat fluidity of the molded product is lowered and the molded product is easily caused to be blurred. Melamine-based resin molding materials obtained by the dry method have the problem that the melamine-based resin and the filler are easily separated from each other by the heat flow during molding, resulting in unevenness on the surface of the molded product and a decrease in gloss. Tends to occur.

Several methods have been proposed to improve various disadvantages of the melamine-based resin molding material by the wet method and the dry method.

For example, JP-A-56-57834 discloses "1) a solid resin obtained by drying a melamine resin syrup, a pre-impregnated filler obtained by impregnating a filler with the melamine resin syrup and then drying. A method for producing a melamine resin molding material, comprising mixing an inorganic filler and an additive to be added as required. ] Has been disclosed. This proposal is a so-called compromise between the wet method and the dry method.Specifically, a melamine solid resin powder, a pre-impregnated filer, an inorganic filer, and additives to be blended as required are crushed and mixed by, for example, a ball mill. To obtain a melamine resin molding material. However, molded articles obtained from this molding material are still insufficient in terms of crack resistance and impact resistance.

For example, JP-A-59-129248 discloses "(1) solid amino compound, solid formaldehyde,
A method for producing an amino resin molding material, comprising granulating a kneaded product obtained by kneading powder pulp, a catalyst and a release agent. In the examples, Hencier mixer was added by adding specific amounts of powdered pulp, zinc stearate and hexamethylenetetramine to an amino resin obtained by reacting urea and paraform under heat and dissolving. And a method for producing a granular amino resin molding material by kneading and extruding the mixture with an extruder. However, this proposal basically belongs to the above-mentioned dry method, and cannot avoid the drawbacks of the dry method.

[Problems to be solved by the invention]

The present inventors have solved the above-mentioned problems of the melamine-based resin molding material by a wet method or a dry method, and have excellent heat fluidity during molding, and the appearance, crack resistance, and crack resistance of the obtained molded product. As a result of intensive research to obtain a melamine-based resin molding material with excellent impact properties, etc., (A)
A pre-dried product obtained by heating and kneading a melamine-based resin molding material pre-dried product, (B) a powdered melamine-based resin, and (C) a melamine-based resin molding material powder containing a specific amount of powder pulp is re-used. It has been found that these problems can be solved at once by crushing, and the present invention has been completed.

[Means for solving the problem]

The present invention provides (A) to (C), (A) a melamine-based resin molding material pre-dried product, (B) a powdered melamine-based resin, and (C) a melamine-based resin containing powdered pulp. Molding material powder,
The amount of the component (A) in 100% by weight of the molding material powder is 2%.
0-60% by weight, the amount of component (B) is 25-60% by weight, (C)
The melamine-based resin molding material powder in which the amount of the components is 5 to 30% by weight and the total amount of (A) to (C) is 85 to 100% by weight is obtained by re-crushing the preliminarily heated and kneaded preform. It is an object of the present invention to provide a melamine-based resin molding material composition characterized by the following.

 Hereinafter, the present invention will be described in detail.

The melamine resin molding agent material powder used in the present invention includes the following (A) to (C), (A) a melamine resin molding material pre-dried product, (B) a powdered melamine resin, and (C) a powdery material. It contains pulp.

The (A) melamine-based resin molding material pre-dried product (hereinafter, may be simply referred to as a pre-dried product) is obtained by drying a wet kneaded product containing melamine resin and pulp as main components. Means a popcorn-like product obtained by

Examples of the melamine-based resin include a melamine resin obtained by reacting melamine and formaldehyde; a melamine-based co-condensation resin obtained by reacting melamine, formaldehyde, and a melamine co-condensation component co-condensable therewith; And / or a melamine-based co-condensation resin, and a melamine-based blended resin obtained by blending a blending resin component made of a thermosetting or thermoplastic resin other than these.

As the melamine co-condensation component, for example, urea,
Ureas such as thiourea and ethylene urea; guanamines such as benzoguanamine, acetoguanamine, formguanamine, phenylacetoguanamine and CTU guanamine; other amino compounds such as guanidine, dicyandiamide, paratoluenesulfonamide; phenol, cresol, xylenol Phenols such as ethyl phenol, butyl phenol and bisphenol A; other melamine cocondensation compounds such as xylene and sucrose; and the like. These components may be used in combination.

Examples of the resin component for blending include thermosetting resins such as urea-based resins, guanamine-based resins, phenol-based resins (novolak type, resol type), xylene resins, epoxy resins, alkyd resins, and unsaturated polyester resins; Examples thereof include thermoplastic resins such as vinyl resins, vinyl acetate resins, acrylic resins, and polyethylene terephthalate resins.

In the melamine-based co-condensation resin, the ratio of the melamine co-condensation component to melamine is about a molar ratio from the viewpoints of surface hardness, light (weather) resistance, heat resistance, and stain resistance of the obtained molded article. It is preferably not more than 0.7 and not more than about 1 by weight, more preferably not more than about 0.5 by mole, and particularly preferably not more than about 0.2 by mole. Further, the weight ratio of the blending resin component to the melamine resin and / or the melamine-based co-condensation resin in the melamine-based blended resin is preferably about 1 or less from the same viewpoint, more preferably about 0.5 or less, About 0.2
It is particularly preferred that:

The melamine resin or melamine-based co-condensation resin is preferably reacted with formaldehyde in an amount of about 1 to about 3 moles, based on 1 mole of melamine alone or a total of 1 mole of the melamine and the melamine co-condensation component, and about 1.4 to about 2.5 moles. It is particularly preferred to carry out the molar reaction. When the above molar ratio exceeds the upper limit of the above range, the molded article tends to become brittle, properties such as crack resistance may decrease, and when the above molar ratio is less than the lower limit of the above range, There is a tendency that the curing rate of the obtained melamine-based resin molding material composition tends to decrease, and the state of "soldering" of the melamine-based molded article may also deteriorate.

The term "formaldehyde" as used herein is intended to include a compound such as paraformaldehyde that substantially acts as formaldehyde when reacting with the melamine and the melamine co-condensation component.

Further, the formaldehyde may partially react with aldehyde components other than formaldehyde, for example, aliphatic aldehydes such as acetaldehyde; aromatic aldehydes such as benzaldehyde; furfural; and other aldehyde compounds capable of reacting with the melamine and the melamine co-condensation component. Can be replaced by

The amount of the aldehyde component other than the above-mentioned formaldehyde is about 0.5 mol or less based on 1 mol of formaldehyde from the viewpoint of the reactivity with melamine and the melamine co-condensation component and the curing rate of the obtained melamine-based resin molding material composition. It is preferred that

Among such melamine-based resins, resins used in the present invention include melamine resins, melamine-phenol co-condensation resins, melamine-urea co-condensation resins, blend resins obtained by blending novolak phenol resins with melamine resins, and melamine resins. A blend resin obtained by blending a urea resin with a resin is preferable, and a melamine resin is most preferable.

As a method for producing the melamine resin used in the present invention, for example, a carbide method, a so-called melamine crystal powder that can be produced by a method known per se such as a urea method, and a so-called melamine crystal powder used as necessary, for example, urea, guanamine, phenol, etc. A melamine co-condensation component and formaldehyde in the form of, for example, a 36% by weight aqueous solution of formalin are reacted in an aqueous solvent at a pH of about 7 to 9, and then, if necessary, further, for example, a urea resin, a phenol resin or the like. Can be blended in the form of, for example, an aqueous solution or an aqueous dispersion to obtain an aqueous solution or an aqueous dispersion.

The pre-dried product (A), which is a component of the present invention, is obtained by drying a wet kneaded product containing the melamine-based resin and pulp described above as main components.

The pulp usually refers to a chain polymer mainly composed of α-cellulose derived from a cellulose raw material, which is a raw material of paper, chemical fiber, cellulosic plastic, or the like,
Generally, industrially, fibers produced from wood and cellulose raw materials treated with linter are used.

The content of the pulp in 100% by weight of the pre-dried product (A) is about 20 to about 40% by weight. It is preferable from the viewpoint of excellent properties such as cracking property and impact resistance.

The above-mentioned “comprising melamine resin and pulp as the main components” means that the pre-dried product (A) is 100% by weight.
Medium, the total of melamine resin and pulp is generally 60 to 10
0% by weight, preferably 80 to 100% by weight.

The pre-dried product (A) includes, in addition to the melamine resin and pulp, a melamine resin heat fluidity improver (hereinafter, may be simply referred to as a flowability improver), a filler other than pulp, It may contain a curing catalyst, a coloring pigment, a lubricant and the like.

As the fluidity improver, for example, polyethylene glycol, polypropylene glycol, polyalkylene glycols such as polyethylene glycol polypropylene glycol blow stick copolymer; for example, polyoxyalkylene and C _8, such as polyethylene glycol monooleate, polyethylene glycol distearate mono- and saturated or unsaturated higher fatty -C ₂₀ - or di -
Esters; for example, polyoxyethylene monolauryl ether, mono and saturated or unsaturated higher aliphatic monoalcohol polyoxyalkylene and C ₈ -C ₂₀ such as polyoxyethylene dioleyl ether - or di - ethers; e.g. , monoethers of alkylphenols polyoxyalkylene and C ₁₂ -C ₂₀ polyoxyethylene nonylphenol ether; for example, methyl oleate, ethyl oleate, n- propyl oleate, i- propyl oleate, n- butyl stearate , N-hexyl laurate, n-octyl oleate, 2-ethylhexyl oleate and the like, and C ₁ -C ₁₀ saturated aliphatic monoalcohols and C ₈ -C ₂₀ saturated or unsaturated higher fatty acids (preferably oleic acid) With esters; for example, trimethylolpropane triole DOO general formula _{C (CH 2 OH) 2+ n} (CH 2 R) , such as pentaerythrityl Chi tall trioleate _2-n [However,
n is 0, 1 or 2, R is hydrogen or an alkyl group of C ₁ -C _3]
And C _{6 to} C ₂₅ (preferably C _{10 to} C ₂₀ )
Esters with saturated or unsaturated higher fatty acids (preferably oleic acid); for example, amides of C ₈ -C ₂₀ saturated or unsaturated higher fatty acids such as stearamide, oleamide, linoleamide, etc .; Phthalic acid diesters of C _{4 to} C ₁₂ saturated alcohols such as dioctyl phthalate and dibutyl phthalate; other fluidity improvers such as ε-caprolactam and glycerin;
Can be exemplified. Among these, from the viewpoint of excellence in appearance of a molded article obtained, a polyethylene glycol-polypropylene glycol blow stick copolymer; mono- and saturated or unsaturated higher fatty acid polyoxyalkylene and C ₈ -C ₂₀ - or di - esters Esters of C _{1 to} C ₁₀ saturated aliphatic monoalcohols and C _{8 to} C ₂₀ saturated or unsaturated higher fatty acids; and a compound of the general formula C (CH ₂ OH) _{2 + n} (CH ₂ R)
Esters of the compound represented by _2-n and a C ₆ -C ₂₅ saturated or unsaturated higher fatty acid are preferred. The content of these fluidity improvers is preferably from 0 to 2.5% by weight, particularly preferably from 0.1 to 2% by weight, based on 100% by weight of the pre-dried product (A).

Examples of the filler include inorganic fillers such as rock wool, glass fiber, glass powder, calcium carbonate, gypsum, barium sulfate, talc, clay, and silica. The pre-dried product of the filler can be used. (A) The amount occupying in 100% by weight is preferably 0 to 40% by weight, particularly preferably 0 to 20% by weight.

Examples of the curing catalyst include phthalic anhydride, p
-Toluene sulfonic acid, dimethyl oxalate, dibenzyl oxalate, dimethyl phthalate, benzoyl peroxide, epichlorohydrin, p-toluenesulfonic acid triethanolamine salt, 2-aminoethylsulfonic acid, dimethylanilinesulfonic acid hydrochloride, melamine oxalate, Examples thereof include ammonium chloride, ammonium phosphate, trimethyl phosphate, acetamide, oxamide, and the like. The amount of the curing catalyst in 100% by weight of the pre-dried product (A) is 0 to 2% by weight, and in particular, It is preferably from 0 to 1% by weight.

Examples of the coloring pigments include titanium oxide, zinc oxide, zinc sulfide, red iron oxide, dark blue, iron black, ultramarine, carbon black, lithopone, titanium yellow, cobalt blue, Hansa yellow, benzidine yellow, lake red, aniline black, Examples thereof include inorganic or organic pigments such as oxazine biolet, quinacridone red, quinacridone biolet, naphthol yellow, phthalocyanine blue, and phthalocyanine green. The amount of the color pigments in 100% by weight of the pre-dried product (A) is preferably 0 to 8% by weight, particularly preferably 0 to 5% by weight.

Examples of the lubricant include zinc stearate, zinc myristate, aluminum stearate, and calcium stearate. The amount of the lubricant in 100% by weight of the pre-dried product (A) is 0 to 3% by weight. And particularly preferably 0 to 2% by weight.

The pre-dried product (A) used in the present invention can be suitably prepared, for example, by a so-called wet method as described below.

That is, for example, a resin solid content concentration of about 40 to about 60% by weight
The proportion of pulp in the aqueous solution of the melamine-based resin in about 100% by weight of the pre-dried product (A) is, for example, 2%.
0 to 30% by weight, and if necessary, the fluidity modifier such as, for example, methyl oleate, trimethylolpropane triolate, etc., in the pre-dried product (A).
For example, 0.1 to 2% by weight in 100% by weight is added, kneaded, and dried at a temperature of about 70 ° to about 100 ° C., for example, a popcorn having a diameter of about 3 cm to 0.5 cm. The above pre-dried product (A) is obtained.

As a kneading means at the time of the above-mentioned popcorn-like material formation,
A kneader, a co-kneader or the like can be used, and examples of the drying means include hot air drying, band dryer drying, fluidized drying and the like.

The pre-dried product (A) thus obtained is mixed with a powdered melamine-based resin (B) and powdered pulp (C), which will be described later, and pulverized by an appropriate means such as a ball mill to obtain melamine. Although it can be made into a resin-based molding material powder, it is preferable that the powder is preliminarily pulverized before being mixed with the powdered melamine resin (B) and the powdered pulp (C).

The above-mentioned pulverizing treatment can be performed by means such as an impact hammer mill, a ball mill, a vibration mill, and a tower mill. If desired, for example, after preliminarily pulverizing with an impact-type hammer mill, pulverization may be further performed by means such as a ball mill, vibration mill, or tower mill.

The melamine-based resin molding material powder used in the present invention contains the powdery melamine-based resin (B) and the powder pulp (C) together with the pre-dried product (A).

The powdery melamine-based resin (B) is the melamine-based resin used for producing the pre-dried product (A), that is,
It is obtained by subjecting a resin solution of a melamine resin, a melamine-based co-condensation resin or a melamine-based blended resin to drying treatment by an appropriate method such as hot air drying, drying under reduced pressure, spray drying and the like, and pulverizing as necessary. The above-mentioned curing catalyst, inorganic filler, coloring pigment and the like used in the production of the pre-dried product (A) may be added in advance to the resin liquid of the melamine resin.

As the melamine-based resin, it is preferable to use a melamine resin from the viewpoint of the surface hardness, light (weather) resistance, heat resistance, stain resistance and the like of the obtained molded article.

As the powder pulp (C), a commercially available powder pulp can be used as it is.

The amounts of the components (A), (B) and (C) in 100% by weight of the melamine resin molding material powder are as follows:
20-60% by weight (preferably 20-50% by weight), 25
-60% by weight (preferably 30-55% by weight) and 5-30% by weight (preferably 10-25% by weight).
The total of the component (C) is 85 to 100% by weight (preferably 90 to 100% by weight).
% By weight). When the amount of the component (A) is less than the lower limit,
The powder fluidity of the molding material powder tends to be insufficient, and the drawability from a mixer such as a super mixer described below and the workability at the time of pre-molding by heating and kneading are deteriorated, often resulting in a decrease in productivity. If the upper limit is exceeded, the resulting molded article tends to lack crack resistance and surface gloss, which is not preferred.

When the amount of the component (B) is less than the lower limit, the resulting molding material composition often has insufficient heat fluidity, and it is difficult to obtain a satisfactory molded product. It is not preferable because workability at the time of kneading preforming is deteriorated.

When the amount of the component (C) is less than the lower limit, crack resistance and impact resistance of the obtained molded article tend to decrease. When the amount exceeds the upper limit, the heat flow of the obtained molding material composition is reduced. This is not preferred because the properties tend to decrease, and poor molding and poor surface gloss of the molded product are likely to occur. When the total value of the components (A) to (C) is less than the lower limit, the appearance of the molded product such as skin, surface gloss, and uneven color is deteriorated, and the coloring property and toning stability of the molding material composition are deteriorated. Sex and the like tend to decrease, which is not desirable.

The melamine-based resin molding material powder used in the present invention includes, in addition to the pre-dried product (A), the powdered melamine-based resin (B) and the powdered pulp (C), an inorganic filler, a fluidity improver,
It may contain a curing catalyst, a coloring pigment, a lubricant and the like.

Examples of the inorganic filler include, for example, anhydrous gypsum, hemihydrate gypsum, barium sulfate, talc, clay, and the like, and the amount of the inorganic filler is 0 to 100% by weight of the total of the molding material powder. The amount is preferably 15% by weight, especially about 0 to 10% by weight. The use of the inorganic filler in the above range is preferable because the molded article obtained has a smooth skin and excellent crack resistance.

Examples of the fluidity improving agent, the used in the preliminary dried product (A), polyalkylene glycols, mono and saturated or unsaturated higher fatty acid polyoxyalkylene and C ₈ -C ₂₀ - or di - esters, or di - - mono and saturated or unsaturated higher monoalcohol polyoxyalkylene and C ₈ -C ₂₀ ethers, monoethers of alkylphenols polyoxyalkylene and _{C 12 ~C 20, C 1 ~C} 10 saturated aliphatic monoalcohols and C ₈ -C ₂₀
Esters of a saturated or unsaturated higher fatty acid of the general formula C (CH ₂ OH) ₂₊ n (CH ₂ R) ₂ -n [where n is 0, 1 or 2, R is hydrogen or C ₁ -C Esters of a compound represented by formula ( ₃ ) and a C ₆ -C ₂₅ saturated or unsaturated higher fatty acid, an amide of a C ₈ -C ₂₀ saturated or unsaturated higher fatty acid, a C ₄ -C ₁₂ saturated alcohol And other fluidity improvers such as phthalic acid diesters and ε-caprolactam. The amount of the fluidity improver used is 0 to 2% by weight, particularly 0 to 1% by weight, based on 100% by weight of the molding material powder, if necessary, including the amount incorporated in the component (A). %.

As the curing catalyst, the same curing catalyst as that used in the production of the preliminarily dried product (A) can be used, and the amount of the curing catalyst used is, if desired, in the component (A) and / or the component (B). It is preferable that the amount is about 0 to 0.5% by weight based on 100% by weight of the molding material powder, including the amount incorporated therein.

Regarding the coloring pigment, the lubricant and the like, the same ones as those used in the production of the pre-dried product (A) can be used. (B) Including 100% by weight of the molding material powder, including 0%
It is preferably 5% by weight, about 0.05 to 2% by weight.

The melamine-based resin molding material powder used in the present invention is mixed with the melamine-based resin molding material pre-dried product (A), the powdered melamine-based resin (B), the powdered pulp (C), and if necessary, as described above. It comprises an inorganic filler, a fluidity improver, a curing catalyst, a coloring pigment, a lubricant and the like.

The total amount of the pulp [the sum of the amount of the pulp in the pre-dried product (A) and the powdered pulp (C)] in 100% by weight of the molding material powder is determined by the good thermal fluidity of the obtained molding material composition. From the viewpoints of good appearance, excellent crack resistance, and excellent impact resistance of the obtained molded product, the content is preferably 15 to 40% by weight, particularly preferably 20 to 35% by weight.

The total amount of the melamine resin in 100% by weight of the molding material powder [the sum of the amount of the melamine resin in the pre-dried product (A) and the powdered melamine resin (B)] is the same as the above. 60-85% by weight, especially 65-80% by weight
It is preferred that

The melamine resin molding material powder is a popcorn-shaped pre-dried product (A), a powdered melamine resin (B),
The powdered pulp (C) and the above-mentioned various compounding agents to be compounded as required are manufactured by pulverizing and mixing using an appropriate pulverizing means such as an impact hammer mixer, a ball mill, a vibration mill, and a tower mill. You can do it,
As described above, the popcorn-shaped pre-dried product (A) is preliminarily pulverized by these appropriate pulverizing means to obtain a powder, and then the components (B) and (C) and, if necessary, are blended. With various compounding agents, for example, using a V-type mixer, super mixer, Nauter mixer, tumbler, omni mixer, Hensiel mixer, Ladyge mixer, ribbon blender, planetary mixer, etc. You can also.

The melamine-based resin molding material powder obtained as described above is once heated and kneaded with an extruder, a heating roll machine, or the like, and the obtained preliminary composition is re-ground to obtain the melamine-based resin molding material composition of the present invention. It can be. In addition,
In this re-pulverization step, it is preferable to re-pulverize to a particle size range so as to be suitable for handling during molding or the like to obtain a granular molding material composition.

At this time, in the heating and kneading, an extruder that is appropriately selected without particular limitation can be used, and examples thereof include a single screw extruder and a twin screw extruder. The compression ratio and the temperature can be appropriately selected, and examples thereof include a compression ratio of 1.1 to 3 and a temperature condition of about 50 to about 130 ° C. The extrusion end of the extruder may be of any type, such as an open type or a screen die type, and the twin-screw extruder may be of the same-direction biaxial type or of the opposite direction biaxial type. Further, the type of the heating roll machine can be appropriately selected.

The re-grinding of the preliminary composition obtained by the heat kneading can be performed by using any re-grinding means capable of forming a re-grinded product. If desired, sieving means may be used in combination. Examples of crushers used for such re-crushing include:
Examples include an impact mill, a hammer mill, an atomizer, a pin mill, a roll mill, and a pulperizer.

The granular melamine-based resin molding material composition thus obtained has a particle size particularly from the ease of handling at the time of molding and the like, preferably, those having passed through a 10 mesh sieve and not passed through a 100 mesh sieve with a JIS sieve, It is preferably at least 80% by weight, more preferably at least 85% by weight. In addition, the conditions of heating and kneading are
Those having a temperature of 80 to 120 ° C. for 10 to 30 seconds are preferable because they exhibit excellent performance as a melamine resin molding material composition. The granular molding material composition exhibits excellent automatic weighing suitability, preheating tableting suitability, dust prevention suitability, and collapse resistance.
It is excellent in molding suitability such as disk flow characteristics, and the obtained molded product is excellent in color unevenness and surface gloss.

The melamine-based resin molding material composition according to the present invention can be molded by a conventionally known method such as compression molding, transfer molding, or injection molding. Further, the molding material composition can be suitably used for multi-stage molding such as multicolor molding by compression molding or the like, patterning molding, surface coating molding or the like.

〔Example〕

Hereinafter, several embodiments of the present invention will be described in more detail with reference to Examples along with Comparative Examples and Reference Examples.

In the following, the automatic weighing suitability (powder flowability),
Test method for suitability for preheating tableting, suitability for preventing dusting, collapse resistance, bleed-out prevention, disk flow characteristics, color unevenness prevention, molded product surface gloss, molded product crack resistance and molded product impact resistance, and The evaluation is as follows.

(1) Suitability for automatic weighing A 3 kg sample was measured 200 mm in diameter x 125 mm in straight body and 175 m in cone height
m, Pour it gently into the center of the hopper with a discharge damper with a discharge opening of 15mmφ. 100mm below the center of the outlet, J
A metal measuring cylinder for measuring the apparent density specified in IS K6911-1979 is placed, and the damper is fully opened to see the material in the measuring cylinder. When the material is full and spills around, close the damper and weigh the sample in the graduated cylinder in the same manner as for the apparent density measurement.
By this method, 30 times (n) of weights are continuously measured,
The standard deviation S of these values is taken as the automatic weighing suitability value.

Where n = 30 i = 1 to 30 yi = measured value of each time (g) = arithmetic mean value of all yi data (g) (2) Suitability for preheating tableting Fuji Electric's high frequency preheater FDP320A, diameter 100 mmφ x height Sa
High-frequency preheating is performed using a 25 mm polyethylene preheater ring and a glass fiber reinforced epoxy laminate (140 × 140 × 2 mm). The preheating condition at this time is a distance between the electrodes of 30 mm and an output of 2 kW at a frequency of 62 MHz.

100 g of the sample is placed in a pre-heater ring placed on a laminate, flattened, and then subjected to high-frequency preheating. The preheated material obtained by such an operation is quickly taken out of the preheater while being placed on the laminate. With the laminate plate removed, the sample, which has been tabletted by preheating, is allowed to fall freely from the inside of the preheater ring. By repeating the above operation, the number of times of preheating at which the weight of the deposit on the preheater ring becomes 5 g or more is determined.

(3) Suitability for preventing dusting In accordance with JIS K6911-1979, a 100 g sample is randomly collected. Gently pour it into a glass cylindrical container with an inner diameter of 50 mm and a height of 500 mm. A No. 2 glass filter with a layer thickness of 5 mm is attached to the lower part of the cylindrical container, and is shaped so that dry air can be blown from the lower part of the container. Dry air is blown at a flow rate of 1 / min for 1 minute from the lower part of the container containing the 100 g sample. By this operation, the weight loss rate (%) spilled out is determined, and the dust loss prevention suitability is determined.

(4) Disintegration resistance A sample of about 100 g is sampled, and a rotary-top shaker, JIS.
The mixture is sieved on a 200φ 80 mesh standard sieve under the conditions of a rotary speed of 290 times / minute, a number of impacts of 156 times / minute, and a total amplitude of 28 mm for 10 minutes. Then, the weight of the sample on the sieve pan was measured,
Thereafter, the sieving operation is continued for 6 hours on the dish, the weight of the sample on the pan under the sieve is measured again, and the disintegration rate is calculated according to the following formula to obtain the value of the disintegration resistance.

Where W ₀ = total weight of the sample (g) W ₁₀ M = weight of the sieved sample after 10 minutes of sieving operation (g) W ₆ H = weight of the sieved sample after 6 hours of sieving operation (g) (5) Disk flow characteristics A 5 g sample was kept at a die temperature of 150 ± 3 ° C using a disk-type test die shown in Section 5.3.2 of JIS.K6911. Place the sample in a conical shape using a metal cylinder of about 10 mm, and apply a load of 2000 kgf within 15 seconds.
Then, compression molding is performed for 2 minutes under a pressure.

Measure the major axis and minor axis of the glossy part of the molded disc to 1 mm with a dimension measuring instrument, calculate the average value, and calculate the elongation (m
m).

(6) Bleed-out prevention A test piece with dimensions of 70 x 60 x 3 mm is molded at a mold temperature of 165 ° C / 165
Molding was performed under the conditions of ° C, a molding pressure of 200 kg / cm ² , and a curing time of 90 seconds. After taking out the molded product, the upper mold was removed and the specular gloss of the surface was measured. The glossiness is measured according to JIS Z8741. The percentage of the specular gloss after molding the material with respect to the specular gloss of the surface of the well-cleaned upper mold is evaluated as the bleed-out prevention property.

(7) Color unevenness prevention 150g molding material preheated to 115 ° C by high frequency preheater
Is supplied to a 9-inch flat mold at a mold temperature of 165 ° C with a 200T hydraulic press, and when the upper and lower mold gaps reach 5 mm or 10 mm, stand still for 0, 2, 4, 6, 8, and 10 seconds, respectively. Then, the pressure is increased immediately, the pressure is maintained at a gauge pressure of 40 kg / cm ² for 2 seconds, and then degassing is performed. Then pressurize again, gauge pressure 100k
After curing at g / cm ² for 65 seconds, the molded article is taken out and allowed to cool. The state of color unevenness on the surface of 12 molded articles of the same material formed in this way is visually evaluated, and the number of molded articles without color irregularity is used as the evaluation score.

(8) Surface gloss of molded product Compression molding of test pieces 70mm long, 60mm wide and 3mm high (115 ℃ high frequency preheating, molding temperature 160 ℃, molding pressure 21
0 kg / cm ² , curing time 90 seconds). The gloss of the molded article was measured using a gloss meter TG-P manufactured by Tokyo Denshoku Co., Ltd. The gloss is measured at an incident angle of 60 ° C., and the gloss is measured with the mirror gloss of the glass surface having a refractive index of 1.567 as 100%.

(9) Molded product crack resistance A bowl with a diameter of 6 inches and a weight of 120 g is compression-molded under the following conditions.

High frequency preheating 115 ° C Mold temperature 165 ° C (upper mold) 160 ° C (lower mold) Pressure 180kg / cm ² Preheating time 60 seconds Degassing time 0.5 seconds Molding time 60 seconds Assuming that one cycle is one cycle, four cycles are carried out a day, and the number of cycles and the number of days until a crack is entered are obtained.

The display of crack resistance is represented by (days)-(cycles). For example, if the number is 2-3, the occurrence of cracks is shown in the third cycle on the second day.

The crack resistance is preferably 4-1 or more.
One or more is particularly preferred.

(10) Molded article impact resistance A flat plate having a diameter of 9 inches and a weight of about 150 g is compression-molded under the same conditions as in (9) Molded article crack resistance.

An impact strength test is performed using the thus formed 9-inch flat plate.

First, a 95 g steel ball is dropped 50 times from a height of 30 cm to a substantially central portion of the flat plate in a prone state. If a crack occurs during that time, the number of steel ball drops until the crack occurs is recorded (for example, if the crack occurs 35 times, it is recorded as 30 cm-35 times). If the crack does not occur even after falling 50 times, increase the height by 10 cm (ie, from the height of 40 cm), repeat the above experiment, and record the height and number of times when the crack occurred (for example, Drop a steel ball from a height of 40 cm.If a crack occurs 25 times, 40
cm-25 times).

Reference Example 1 Melamine (manufactured by Yuka Melamine Co., Ltd .; Yuka Melamine) 12
60 g (10 mol), 1380 g of 37% aqueous formalin solution (17
Mol) and 900 g of water in a flask equipped with a reflux condenser,
The mixture was heated and reacted at 90 ° C. while stirring under the condition of F / M = 1.7. When the cloudiness point of the reaction mixture solution reached 60 ° C., 0.8 g of NaOH was added and cooled to obtain an aqueous solution of a melamine resin precondensate (melamine resin solution). The cloud point used as a measure of the end of the reaction is
Take 5 ml of the reaction mixture solution and add 45m of hot water to about 80 ° C.
The temperature at which white turbidity occurs when adding, stirring and cooling.

To 3,000 g of the melamine resin liquid (solid content: about 50% by weight) thus obtained, 500 g of pulp (about 25% by weight in 100% by weight of the obtained melamine resin molding material pre-dried product) was added. After adding 14 g of oleate (0.7% by weight to 100% by weight of the preliminarily dried melamine resin molding material) and kneading with a kneader, the kneaded material is heated at 90 ° C. for 90 minutes.
The mixture was dried with a hot air drier for minutes to obtain a pre-dried melamine resin molding material in a popcorn shape.

Next, 1500 g of the above pre-dried product was pulverized in a ball mill for about 8 hours to obtain a pre-dried melamine resin molding material powder.

Reference Examples 2 to 5 In Example 1, melamine resin molding material pre-dried powders were obtained in the same manner as in Reference Example 1 except that the type and amount of the fluidity improver were changed, or the flow improver was not used. Table 1 shows various compositions of the obtained pre-dried powder.

Reference Example 6 In Reference Example 1, 3000 g of melamine resin liquid and pulp 5
A melamine resin molding material pre-dried powder was obtained in the same manner except that 2800 g of the melamine resin liquid and 600 g of pulp were used instead of 00 g. Table 1 shows various compositions of the obtained pre-dried powder.

Reference Example A The same melamine resin liquid as used in Reference Example 1 was dried at about 200 ° C. by a spray dryer to obtain a powdery melamine resin.

Example 1 1200 g of the pre-dried product (A) powder of Reference Example 1, 1720 g of powdery melamine resin (B) of Reference Example A, and powder pulp (C) 7
00g, 320 g of hemihydrate gypsum, 40 g of titanium oxide, 2 g of phthalic anhydride and 22 g of zinc stearate were mixed for about 10 minutes using a super mixer to obtain a homogeneous melamine resin molding material powder. Next, this molding material powder was heated and kneaded with a twin-screw extruder. The kneading extruder uses a screw with a shaft diameter of 55 mmφ, L / D = 20 and a compression ratio of 2.0, the composition powder supply speed is 20 kg / min, the cylinder temperature is 100 ° C., and the screw rotation speed is 100 rp.
Under the conditions of m, a heat-extruded kneaded melt-molded product was obtained.

After coarsely crushing this kneaded molded product, screen diameter 2mmφ
To obtain a granular melamine resin molding material composition.

Table 2 shows various characteristics of the obtained molding material composition and various physical properties of a molded product obtained by molding the composition.

Example 2 and Comparative Examples 1-2 In Example 1, a granular melamine resin molding material composition was obtained in the same manner as in Example 1, except that the mixing ratio of the components (A) to (C) was changed. Were measured and various physical properties of a molded article obtained by molding the composition were measured. Table 2 shows the composition of the composition and various measurement results.

Examples 3-6 In Example 1, a granular melamine resin was molded in the same manner as in Example 1, except that the pre-dried powders of Reference Examples 2 to 5 were used instead of the pre-dried powder of Reference Example 1 as the component (A). A material composition was obtained, and various properties of the composition and various properties of a molded product obtained by molding the composition were measured in the same manner. Table 2 shows the composition of the composition and various measurement results.

Example 7 In Example 1, the pre-dried powder of Reference Example 6 was used instead of the pre-dried powder of Reference Example 1 as the component (A).
In addition, except that no hemihydrate gypsum is used, a granular melamine resin molding material composition is obtained in the same manner, and thereafter, various properties of the composition and various physical properties of a molded product obtained by molding the composition in the same manner. It was measured. Table 2 shows the composition of the composition and various measurement results.

Example 8 A granular melamine resin molding material composition was obtained in the same manner as in Example 7, except that the mixing ratio of the components (A) to (C) was changed. Various properties of the composition and the composition were similarly obtained. Various physical properties of a molded article obtained by molding the article were measured. Table 2 shows the composition of the composition and various measurement results.

Continuation of the front page (56) References JP-A-60-144357 (JP, A) JP-A-59-202215 (JP, A) JP-A-57-123247 (JP, A) JP-A-56-57834 (JP) JP-A-51-92859 (JP, A) JP-A-61-197651 (JP, A) JP-A-57-117533 (JP, A) JP-A-59-8749 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 61/20-61/32

Claims (1)

(57) [Claims] 1. A melamine resin comprising: (A) to (C); (A) a pre-dried melamine resin molding material; (B) a powdered melamine resin; and (C) a powdered pulp. A resin molding material powder,
The amount of the component (A) in 100% by weight of the molding material powder is 2%.
0-60% by weight, the amount of component (B) is 25-60% by weight, (C)
The melamine-based resin molding material powder in which the amount of the components is 5 to 30% by weight and the total amount of (A) to (C) is 85 to 100% by weight is obtained by re-crushing the preliminarily heated and kneaded preform. A melamine-based resin molding material composition characterized by the following.