JP4554092B2 - Phenolic resin moldings and laminates - Google Patents

Description

（ 測定方法 ）
＊ 寸法変化率 ＪＩＳＫ ６９０２に準じ、伸び＋縮みの合計として表す。
（伸び） ４０±２℃ 、相対湿度９０〜９５％の恒温恒湿装置中に９６時間放置して測定。
（縮み） ７０±２℃の恒温乾燥機に２４時間放置して測定。
＊ 色差 成形した成形品及び４０±２℃、相対湿度９０〜９５％の恒温恒湿装置中に９６時間放置した成形品のＬａｂを分光測色計にて測定し、ハンター色差式に基づき色差ΔＥを求める。
＊ 耐煮沸性 ＪＩＳＫ６９０２に準じる。 ５０ｍｍ角の試験片を２時間煮沸したのち、試験片の層間剥離、充填材の脱落がないかどうかを判定する。
＊ 曲げ強度 ＪＩＳＫ ６９０２に準ずる。
＊ 曲げ弾性率 ＪＩＳＫ ６９０２に準ずる。
【００１７】
本発明になる成形物は硬化したフェノール樹脂中に変性剤が分離し、分散した状態を形成しているため、環境変化により引き起こされるフェノール樹脂層の収縮、膨張の応力が全体に波及することがない。
このため寸法安定性が大幅に改善される。従って本発明に係わる成形物、例えば積層板が他の基材例えばモルタル下地等に接着剤で一体に接合された場合、環境変化に基づく積層板の寸法変化より引き起こされる接着層の剥離、基材の反り並びにクラックの発生が少なくなるなどの効果が得られる。このため各種の基材等との複合化した場合において度々問題となる剥離、そり、クラック等の問題がなくなり安心して利用できる。
また、電気絶縁材等の成形材料として使用されれば、寸法安定性の改善、狂い等の問題がなく品質向上を図ることができる。
更に、フェノール樹脂の周囲に変性剤が分離、分散した構造であるため色差のブレが少なくなり外観も改善される。[0001]
[Industrial application fields]
The present invention relates to a phenolic resin-based molding material, and more particularly to a phenolic resin molding using a resol-based phenolic resin and excellent in dimensional stability and a molding method thereof.
[0002]
[Prior art]
Conventionally, phenolic resins are excellent in performance such as heat resistance, toughness, hardness, and electrical insulation, and are therefore used in a wide range of fields such as insulating plates, decorative plates, molded parts, and adhesives.
[0003]
[Problems to be solved by the invention]
However, molded products using phenolic resin have the disadvantage that the dimensional stability is inferior compared to inorganic materials such as glass and metals, etc., resulting in molding warping, twisting, cracking, peeling of the adhesive part, etc. Defects were potentially left behind. In particular, when the composite material is used in combination with other materials, the above-mentioned defects become prominent, and improvement has been demanded.
Conventionally, there is means such as blending a large amount of an inorganic filler as one method for reducing the dimensional change, but there is a difficulty in reducing the strength of the molded product, and improvement by other methods has been demanded.
[0004]
[Means for Solving the Problems]
In the present invention, as a result of intensive studies to solve the above-mentioned problems, by adding a certain modifier to the phenol resin, not only the dimensional stability is improved, but the color tone of the molding material is reduced. At the same time, it has been found that the effect of reducing the change in color tone over time can be obtained.
[0005]
As a result of a wide range of investigations on modifiers that may be able to achieve these characteristics, by incorporating an alkylene oxide derivative having a hydroxyl group into a resole phenolic resin as a modifier, it dissolves in the state of the blended resin composition. Thus, it has been confirmed that a modifier that forms a structure that is separated from the resin and that is uniformly dispersed in the cured product as the curing proceeds, has led to the present invention. .
Examples of the alkylene oxide derivative include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyethylene glycol glyceryl ether, and polypropylene glycol glyceryl ether.
Further, the alkylene oxide derivative can be phase-separated and uniformly dispersed by adding a compound having polymerizability in the molecule to the resol phenol resin, polymerizing it in the curing process, and increasing the molecular weight.
Examples of these include polyalkylene glycol (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate, and allylated polyethers such as polyethylene glycol allyl ether and polypropylene glycol allyl ether. .
[0006]
As the compound which is separated and dispersed in the curing process of the resole phenolic resin, the higher the molecular weight is, the easier it is to separate the phases. However, if the hydrophobicity and molecular weight are higher than a certain level, they may become insoluble in the resol-based phenol resin solution, or may be separated in the curing process but may not be uniformly dispersed but may ooze out in liquid form.
These phenomena vary depending on the reaction ratio of phenol and formaldehyde, reaction catalysts such as co-condensing compounds such as alkylphenols and amino compounds, modifiers such as added plasticizers, and molding conditions. Depending on the characteristics, it is necessary to adjust and select the type, molecular weight and addition amount of the alkylene oxide derivative.
[0007]
In order to realize the object of the present invention, it is necessary that the resin and the modifier are dissolved in the resin liquid state, and that the modifier is separated and uniformly dispersed in the cured resin. . The objective cannot be achieved if the resin is uniformly dissolved in the cured resin.
In the present invention, whether or not the modifier is separated and dispersed in the cured resin depends on whether it is in a transparent uniform state, a milky turbid state, or if the modifier is exuded at the time of curing. I can judge. If it is in a transparent and uniform state, it is determined that the resin and the modifier are uniformly dissolved and cured. If it is milky, it is determined that the resin and the modifier are separated and dispersed. When the modifier is exuded, it is determined that the modifier is separated without being uniformly dispersed in the cured resin.
[0008]
In the present invention, the molar ratio of formaldehyde / phenol is preferably 1 to 3, and the addition ratio of the modifier to the phenol resin solid content is 5 to 80%.
If the addition rate is 5% or less, the separation and dispersion state cannot be obtained sufficiently and the purpose cannot be achieved. If it is 80% or more, the toughness, heat resistance, etc. of the phenol resin are impaired, which is not preferable.
The modifier may be blended at the beginning of the reaction, but it may be blended after the initial condensate of phenol and formaldehyde is synthesized.
In addition, the phenol resin can be used alone, but can also be applied to a modified resin to which a cocondensate with an alkylphenol, an amino compound or the like, paratoluenesulfonamide, caprolactam, or the like is added.
[0009]
An example of a laminate as a molded article according to the present invention will be described. Papers, nonwoven fabrics, sheets, woven fabrics, etc., which are obtained by processing the resin material thus prepared from fibers such as glass fibers, cellulose fibers, and synthetic fibers. A plurality of impregnated sheets impregnated into a base material are laminated, and hot-press molded to finish a laminated plate. Moreover, it may be finished by pasting a decorative layer on the surface of the laminated plate or by applying a coating or the like.
Alternatively, on the impregnated sheet prepared in this manner, another resin-impregnated sheet such as decorative paper impregnated with a resin such as a melamine resin or an unsaturated polyester resin can be molded, It can also be finished as a decorative laminate by laminating decorative sheets.
[0010]
Example Synthesis of resol phenolic resin A flask equipped with a stirrer, thermometer, and cooling condenser was charged with 1 mol of phenol and 1.3 mol of a 47% formalin aqueous solution (in terms of formaldehyde), and adjusted to pH 8.0 with sodium hydroxide. . The temperature of the reaction solution was raised and the reaction solution was maintained at 95 ° C., and the reaction was continued until the cloudiness start temperature of the reaction solution reached 40 ° C. Thereafter, the mixture was cooled and diluted with methanol to obtain a resol type phenol resin (hereinafter referred to as Resin A) having a solid content of 50%.
[0011]
Example 1
Resin composition in which 20 parts of polypropylene glycol having an average molecular weight of 4000 and a hydroxyl value of 26 (KOHmg / g) and 20 parts of methanol are added to 100 parts by weight (hereinafter referred to simply as “parts”) of Resin A obtained in Examples 1 I got ▼.
The resin solid material obtained by dripping the resin composition (1) on a hot plate at 140 ° C. and curing was a uniform milky brown color, and there was no bleeding of polypropylene glycol.
[0012]
Example 2
100 parts of the resin A obtained in the examples, 20 parts of polypropylene glycol monoallyl ether having an average molecular weight of 1500 and a hydroxyl value of 39 (KOHmg / g), and t-butylperoxy-2-ethylhexano as a radical polymerization initiator A transparent brown resin composition (2) to which 0.75 parts of ate and 20 parts of methanol were added was obtained.
The resin composition (2) was dropped on a hot plate at 140 ° C., and the cured resin solid was a uniform milky brown color, and there was no bleeding of polypropylene glycol monoallyl ether.
[0013]
Comparative Example 1
Resin A obtained in the examples was used as Comparative Example 1 as it was. The resin of Comparative Example 1 was dropped on a hot plate at 140 ° C., and the cured resin solid had a uniform transparent dull color.
[0014]
Comparative Example 2
Transparent brown resin composition of Comparative Example 2 in which 20 parts of polypropylene glycol having an average molecular weight of 400 and a hydroxyl value of 279 (KOHmg / g) and 20 parts of methanol were added to 100 parts of the resin A obtained in the examples (3) I got ▼. The resin solid material obtained by dripping the resin composition (3) on a hot plate at 140 ° C. and curing was uniform and transparent, and there was no bleeding.
[0015]
A molded product was molded according to the following using each of the resin compositions of the above Examples and Comparative Examples.
(Composition)
Resin A and (1) to (3) Composition 100 parts by weight Calcium carbonate 200 parts by weight This blend was diluted with methanol to obtain a slurry for impregnation coating.
The slurry was impregnated and coated on a glass fiber nonwoven fabric having a basis weight of 75 g / m 2 and a density of 0.15 g / m 3 and then dried to obtain a prepreg sheet for lamination having a basis weight of 900 g / m 2.
Seven prepreg sheets were laminated and molded at 150 ° C. and 9.8 MPa (100 kg / cm 2) for 30 minutes to obtain a laminated plate having a thickness of 3 mm. Table 1 shows the rate of dimensional change and the degree of color tone change of the laminate.
[0016]
[Table 1]

( Measuring method )
* Dimensional change rate Expressed as the sum of elongation + shrinkage in accordance with JISK 6902.
(Elongation) Measured by leaving it in a constant temperature and humidity apparatus of 40 ± 2 ° C. and a relative humidity of 90 to 95% for 96 hours.
(Shrinkage) Measured by leaving in a constant temperature dryer at 70 ± 2 ° C. for 24 hours.
* Color difference The Lab of the molded product and the molded product left for 96 hours in a constant temperature and humidity device with a temperature of 40 ± 2 ° C and relative humidity of 90 to 95% was measured with a spectrocolorimeter, and the color difference ΔE based on the Hunter color difference equation. Ask for.
* Boiling resistance Conforms to JISK6902. After boiling a test piece of 50 mm square for 2 hours, it is determined whether there is no delamination of the test piece or dropping of the filler.
* Bending strength Conforms to JISK 6902.
* Flexural modulus According to JISK 6902.
[0017]
In the molded product according to the present invention, since the modifier is separated and dispersed in the cured phenol resin, the shrinkage and expansion stress of the phenol resin layer caused by the environmental change may be spread over the whole. Absent.
For this reason, dimensional stability is greatly improved. Therefore, when the molded product according to the present invention, for example, a laminate is integrally bonded to another substrate such as a mortar substrate with an adhesive, peeling of the adhesive layer caused by a change in the size of the laminate due to environmental changes, the substrate Such effects as less warpage and occurrence of cracks can be obtained. For this reason, problems such as peeling, warping and cracks, which are often problematic when combined with various base materials, are eliminated and can be used safely.
Further, if used as a molding material such as an electrical insulating material, it is possible to improve quality without problems such as improvement in dimensional stability and deviation.
Furthermore, since the modifier is separated and dispersed around the phenol resin, the color difference blur is reduced and the appearance is improved.

Claims (2)

A phenolic resin-based molded product formed by using a condensation product of phenol and formaldehyde as a cured resin component, wherein the cured resin component is blended in a state where polypropylene glycol or polypropylene glycol monoallyl ether is dissolved, In the cured resin product, the polypropylene glycol or polypropylene glycol monoallyl ether is separated and dispersed, and the cured resin product is milky white, and is a phenol resin-based molded product. A laminate obtained by impregnating a base material with the cured resin component according to claim 1 and hot-pressing it .