JPH0711221A - Adhesive - Google Patents

Abstract

PURPOSE:To obtain an amino resin-synthetic resin emulsion adhesive having long pot life, free from the separation of phase and the formation of solid material and useful for the bonding of plywood, decorative plywood or paper tube. CONSTITUTION:This adhesive is composed of (A) an amino resin (urea-formaldehyde resin) having a condensation degree to cause the clouding at 5-30 deg.C in the form of a 10wt.% aqueous solution and (B) a synthetic resin emulsion (vinyl acetate resin emulsion). Since the adhesive has long pot life, it has high flexibility in use and enables uniform bonding.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、突き板合板、合板、紙
管等の製造に使用する接着剤に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive used for manufacturing veneer plywood, plywood, paper tubes and the like.

【０００２】[0002]

【従来の技術】突き板合板、合板、紙管等を製造する際
に用いる接着剤として、酢酸ビニル樹脂エマルジョン、
エチレン・酢酸ビニル樹脂エマルジョン、スチレン・ブ
タジエン共重合エマルジョン等の合成樹脂エマルジョン
に、尿素・ホルムアルデヒド縮合樹脂、メラミン・ホル
ムアルデヒド縮合樹脂等のアミノ樹脂を使用直前に配合
混合したものが、合成樹脂エマルジョンの良好な仮接着
性およびアミノ樹脂の耐水性がうまく発揮できることか
ら広く使用されている。2. Description of the Related Art Vinyl acetate resin emulsions are used as adhesives when manufacturing veneer plywood, plywood, paper tubes, etc.
Synthetic resin emulsions such as ethylene / vinyl acetate resin emulsions and styrene / butadiene copolymer emulsions, and amino resins such as urea / formaldehyde condensation resin and melamine / formaldehyde condensation resin mixed and mixed immediately before use are good synthetic resin emulsions. It is widely used because of its good temporary adhesion and good water resistance of amino resin.

【０００３】[0003]

【発明が解決しようとする課題】しかしこの混合方法
は、両者の最適混合条件が確立されておらず、相溶性不
良の場合は、分離・増粘する事がしばしば起き、接着力
が十分に得られないので、通常は使用直前に混合使用さ
れている。そのため、使用に際しては均一に混合するた
めに少量を頻繁に配合する必要がある。また、貯蔵安定
性に優れる一液混合型の接着剤を得ることは困難であっ
た。However, in this mixing method, the optimum mixing conditions for the two have not been established, and when compatibility is poor, separation and thickening often occur, and sufficient adhesive strength is obtained. Therefore, it is usually used as a mixture just before use. Therefore, in use, it is necessary to frequently mix a small amount in order to mix uniformly. Further, it has been difficult to obtain a one-component mixed type adhesive having excellent storage stability.

【０００４】[0004]

【課題を解決するための手段】本発明者らは、これらの
問題点を解決するため鋭意研究した結果、アミノ樹脂の
縮合度（樹脂濃度１０重量％の水溶液の白濁温度で判定
する。後述）が合成樹脂エマルジョンとの相溶性におい
て重要な影響を及ぼすことを見出し、本発明を完成し
た。Means for Solving the Problems As a result of intensive studies for solving these problems, the present inventors have determined the degree of condensation of amino resin (determined by the cloudiness temperature of an aqueous solution having a resin concentration of 10% by weight, which will be described later). The present invention has been completed based on the finding that is important for compatibility with synthetic resin emulsions.

【０００５】即ち、本発明は、縮合度が５〜３０℃であ
るアミノ樹脂と合成樹脂エマルジョンからなることを特
徴とするエマルジョン−アミノ樹脂系接着剤である。That is, the present invention is an emulsion-amino resin type adhesive characterized in that it comprises an amino resin having a condensation degree of 5 to 30 ° C. and a synthetic resin emulsion.

【０００６】以下本発明について詳述する。合成樹脂エ
マルジョンとして、酢酸ビニル樹脂エマルジョン、エチ
レン・酢酸ビニル樹脂エマルジョン、スチレン・ブタジ
エン共重合エマルジョン、アクリルエステル樹脂系エマ
ルジョン、塩化ビニル樹脂系マルジョン、塩化ビニリデ
ン樹脂系エマルジョン、ポリスチレンエマルジョン、ポ
リエチレンエマルジョン、ポリブテンエマルジョンなど
が挙げられる。The present invention will be described in detail below. Synthetic resin emulsions include vinyl acetate resin emulsion, ethylene / vinyl acetate resin emulsion, styrene / butadiene copolymer emulsion, acrylic ester resin emulsion, vinyl chloride resin emulsion, vinylidene chloride resin emulsion, polystyrene emulsion, polyethylene emulsion, polybutene emulsion. And so on.

【０００７】アミノ樹脂としては、一般的に、尿素・ホ
ルムアルデヒド縮合樹脂、メラミン・ホルムアルデヒド
縮合樹脂、アニリンアルデヒド縮合樹脂などが挙げられ
る。アミノ樹脂の製造方法としては、尿素・ホルムアル
デヒド縮合樹脂の場合を例に挙げると、ホルムアルデヒ
ドと尿素のモル比を２〜３：１比としｐＨをＮａＯＨに
より約８. ０に調整し、温度を８０〜９５℃に保ち３０
分程度反応させたのち蟻酸にてｐＨを約４. ５にして約
１０分間反応を行い、次いでＮａＯＨでｐＨを４．８〜
６．０とした後、ホルムアルデヒドと尿素のモル比を１
〜２：１比になるように尿素を追加し、溶解させ、さら
に反応を縮合度が所定の温度になるまで行い、さらにＮ
ａＯＨでｐＨを約８としたのちに常温になるまで冷却を
行うのが一般的である。Examples of the amino resin generally include urea / formaldehyde condensation resin, melamine / formaldehyde condensation resin, aniline aldehyde condensation resin and the like. As a method for producing the amino resin, taking the case of a urea-formaldehyde condensation resin as an example, the molar ratio of formaldehyde and urea is 2-3: 1, the pH is adjusted to about 8.0 with NaOH, and the temperature is adjusted to 80%. Keep at ~ 95 ℃ 30
After reacting for about a minute, the pH is adjusted to about 4.5 with formic acid and the reaction is performed for about 10 minutes, and then the pH is adjusted to 4.8 to about 4 with NaOH.
After setting to 6.0, the molar ratio of formaldehyde to urea is 1
Urea is added and dissolved in a ratio of up to 2: 1 and the reaction is further carried out until the condensation degree reaches a predetermined temperature.
It is common to adjust the pH to about 8 with aOH and then cool to room temperature.

【０００８】メラミン・ホルムアルデヒド縮合樹脂の場
合は、ホルムアルデヒドとメタノールとメラミンのモル
比を１. ５〜４. ５：１〜５：１比とし、ｐＨをＮａＯ
Ｈにより１０〜１３に調整し、温度を８０〜９０℃に保
ち、この時の縮合度を所定の程度になる迄反応を進めた
のち速やかに常温になるまで冷却を行うのが一般的であ
る。In the case of the melamine-formaldehyde condensation resin, the molar ratio of formaldehyde, methanol and melamine is 1.5 to 4.5: 1 to 5: 1 and the pH is NaO.
It is common to adjust to 10 to 13 with H, maintain the temperature at 80 to 90 ° C., proceed the reaction until the degree of condensation at this time reaches a predetermined degree, and then quickly cool to room temperature. .

【０００９】アミノ樹脂の縮合度を測定することは種々
の縮合程度のものの混合物であるため困難であり、平均
的な縮合度の尺度として、水溶液での白濁温度を用いる
ことが便利である。本発明では、後述する測定方法で測
定した樹脂濃度１０重量％の水溶液の白濁温度を縮合度
とする。It is difficult to measure the degree of condensation of the amino resin because it is a mixture of various degrees of condensation, and it is convenient to use the cloudiness temperature in an aqueous solution as a measure of the average degree of condensation. In the present invention, the degree of condensation is defined as the cloudiness temperature of an aqueous solution having a resin concentration of 10% by weight measured by the measuring method described later.

【００１０】本発明で用いるアミノ樹脂は縮合度が３０
℃以下のものが好ましく、通常５〜３０℃のものであ
る。なお、上記のように製造したアミノ樹脂では通常ア
ミノ基１モルに対するホルムアルデヒドの量は０．５〜
１．５モルの条件で得られるものである。The amino resin used in the present invention has a condensation degree of 30.
It is preferably not higher than 0 ° C, usually 5 to 30 ° C. In addition, in the amino resin produced as described above, the amount of formaldehyde is usually 0.5 to 1 mol of amino group.
It is obtained under the condition of 1.5 mol.

【００１１】合成樹脂エマルジョンとの相溶性は、上記
条件にあるアミノ樹脂ではいずれの割合においても良好
であり、配合時に混合しても良いし、あらかじめアミノ
樹脂と合成樹脂エマルジョンとを混合しても良い。あら
かじめ混合する場合は、アミノ樹脂の反応を防止するた
め、一般的な酸又は、アルカリでｐＨを７〜１０に調整
することにより長期間にわたり分離、増粘を起こさず安
定性に優れる接着剤を得ることができる。アミノ樹脂の
縮合度が３０℃を越えると合成樹脂エマルジョンとのい
ずれの混合割合においても相溶性が悪くなり、接着され
た突き板合板、合板、紙管、等の接着力が不安定とな
り、実用的でなくなる。また、アミノ樹脂の縮合度が４
℃以下である場合は、合成樹脂エマルジョンとの相溶性
は良いが接着力が十分でなくなり実用的でなくなる。The compatibility with the synthetic resin emulsion is good in any proportion of the amino resin under the above conditions, and they may be mixed at the time of compounding, or the amino resin and the synthetic resin emulsion may be mixed in advance. good. In case of pre-mixing, in order to prevent the reaction of amino resin, by adjusting the pH to 7 to 10 with a general acid or alkali, an adhesive with excellent stability that does not cause separation or thickening over a long period of time is prepared. Obtainable. If the degree of condensation of the amino resin exceeds 30 ° C, the compatibility will be poor at any mixing ratio with the synthetic resin emulsion, and the adhesive strength of the bonded veneer plywood, plywood, paper tube, etc. will become unstable, making it practical. It becomes untargetable. Also, the condensation degree of the amino resin is 4
When the temperature is lower than 0 ° C, the compatibility with the synthetic resin emulsion is good, but the adhesive strength is insufficient and it becomes unpractical.

【００１２】[0012]

【実施例】以下、実施例、比較例によりさらに詳細に説
明するが本発明は、これらに限定されるものではない。EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

【００１３】評価方法 （Ａ）アミノ樹脂の縮合度の測定方法 １００ｍｌのメスシリンダーに樹脂重量濃度が１０％に
なるように樹脂と蒸留水を加え、約１００ｍｌとする。
速やかに温度計で水と樹脂が良く混和するようにかき混
ぜる。この液の色相が、白濁した場合は加温水槽、透明
の場合は冷却水槽で、メスシリンダー内の液がわずかに
濁りを生じるように温度を調整する。この時の温度を読
みとり縮合度とする。Evaluation Method (A) Method for Measuring Condensation Degree of Amino Resin Resin and distilled water are added to a 100 ml graduated cylinder so that the weight concentration of the resin is 10%, and the volume is set to about 100 ml.
Immediately stir with a thermometer so that the water and resin mix well. When the hue of this liquid becomes cloudy, the temperature is adjusted so that the liquid in the graduated cylinder becomes slightly turbid by using a warm water tank or a transparent water tank. The temperature at this time is read and used as the condensation degree.

【００１４】（Ｂ）相溶性およびポットライフ（ＰＬ）
のテスト方法 ユリア樹脂木材接着剤ＪＩＳ Ｋ ６８０１−1987 に
規定される３．酢ビ混和性試験に準じて測定した。相溶
性の判定は、分離、増粘等が無く優れており、実用範囲
にあるものを○、実用的でないものを×と示した。ま
た、２５℃で１４日間保存し、分離、増粘等の有無を調
べた。ポットライフの判定は、分離、増粘が無く優れて
おり、実用範囲にあるものを○、実用的でないものを×
と示した。(B) Compatibility and pot life (PL)
2. Test method of urea resin wood adhesive specified in JIS K 6801-1987. It was measured according to the vinyl acetate compatibility test. The compatibility was judged to be excellent without separation, thickening, etc., and those within the practical range were marked with ◯, and those not practical were marked with x. Further, it was stored at 25 ° C. for 14 days, and the presence or absence of separation or thickening was examined. Judgment of pot life is excellent without separation and thickening, and is in the practical range ○, unpractical ×
Was shown.

【００１５】（Ｃ）合板接着力の測定方法 ユリア樹脂木材接着剤ＪＩＳ Ｋ ６８０１−1987 に
規定される６．７．２木材引張せん断接着強さに準じて
測定した。(C) Plywood adhesive strength measurement method Uria resin wood adhesive It was measured according to 6.7.2 wood tensile shear adhesive strength specified in JIS K 6801-1987.

【００１６】（Ｄ）総合評価の方法 どの混合比条件においても相溶性、合板接着力が優れて
おり、ポットライフも良好で、実用範囲にあるものを
○、実用的でないものを×と示した。(D) Method of Comprehensive Evaluation Excellent compatibility, plywood adhesiveness, and good pot life under any mixing ratio condition, and those in the practical range were marked with ◯, and those not practical were marked with x. .

【００１７】実施例１ ２リットルのフラスコに３７％ホルムアルデヒド７２０
ｇと尿素２６６. ４ｇを入れ、２０％ＮａＯＨ水溶液に
よりｐＨを約８に調整し、温水浴により８０〜９５℃で
３０分間反応させたのち、蟻酸にてｐＨを約４. ５にし
て約１０分間反応を行い、次いで２０％ＮａＯＨ水溶液
によりｐＨを約５．２としてから尿素１８．５ｇを追加
し、溶解し、さらに、縮合度が５℃迄になるまで反応を
進め、次いで２０％ＮａＯＨ水溶液によりｐＨを約８と
したのち徐々に常温になるまで冷却を行った。このアミ
ノ樹脂液の固形分は５０重量％であり、縮合度は５℃で
あった。ここで得られたアミノ樹脂液と三井東圧化学
（株）製の酢酸ビニル樹脂エマルジョン「ストラクトボ
ンドＶ−２２２」（商品名、固形分約４０％、ｐＨ約
４、粘度約３００００ＣＰ／２５℃）とを混合し、相溶
性とＰＬと合板接着力を調べた。エマルジョンはあらか
じめ２０％ＮａＯＨ水溶液によりｐＨを約８に調整した
後アミノ樹脂液と混合した。なお、アミノ樹脂／エマル
ジョンの混合割合は重量比で２５／７５、５０／５０お
よび７５／２５である。測定結果を表１に示す。Example 1 37% formaldehyde 720 in a 2 liter flask
g and urea (266.4 g) were added, the pH was adjusted to about 8 with a 20% aqueous NaOH solution, the mixture was reacted in a warm water bath at 80 to 95 ° C. for 30 minutes, and then the pH was adjusted to about 4.5 with formic acid to about 10 After reacting for 20 minutes, the pH was adjusted to about 5.2 with a 20% NaOH aqueous solution, 18.5 g of urea was added and dissolved, and the reaction was allowed to proceed until the degree of condensation reached 5 ° C., then a 20% NaOH aqueous solution. The pH was adjusted to about 8 and then gradually cooled to room temperature. The solid content of this amino resin solution was 50% by weight, and the degree of condensation was 5 ° C. The amino resin solution obtained here and a vinyl acetate resin emulsion "Structobond V-222" manufactured by Mitsui Toatsu Chemicals, Inc. (trade name, solid content about 40%, pH about 4, viscosity about 30,000 CP / 25 ° C) Were mixed, and compatibility, PL and plywood adhesion were examined. The emulsion was previously adjusted to a pH of about 8 with a 20% NaOH aqueous solution and then mixed with the amino resin solution. The mixing ratio of the amino resin / emulsion is 25/75, 50/50 and 75/25 by weight. The measurement results are shown in Table 1.

【００１８】実施例２〜４ 縮合度をそれぞれ１０℃、２０℃、３０℃なるまで反応
を進めた以外は、実施例１と同様にしてアミノ樹脂液を
製造した。得られたアミノ樹脂の固形分は実施例１と同
じであったが、縮合度はそれぞれ１０℃、２０℃、３０
℃であった。以下、実施例１と同様に相溶性とＰＬと合
板接着力を調べた。その結果を表１に示す。Examples 2 to 4 Amino resin solutions were produced in the same manner as in Example 1 except that the reaction was allowed to proceed until the condensation degree reached 10 ° C, 20 ° C and 30 ° C, respectively. The solid content of the obtained amino resin was the same as in Example 1, but the condensation degrees were 10 ° C., 20 ° C. and 30 ° C., respectively.
It was ℃. Hereinafter, the compatibility, PL and plywood adhesive strength were examined in the same manner as in Example 1. The results are shown in Table 1.

【００１９】比較例１〜４ 実施例１において、反応の縮合度をそれぞれ２℃、４０
℃、５０℃、６０℃になるまで反応を進めた以外は、実
施例１と同様にして、アミノ樹脂液を得た。各樹脂の固
形分、縮合度はそれぞれ５０重量％・２℃、５０重量％
・４０℃、５０重量％・５０℃、５０重量％・６０℃で
あった。以下、実施例１と同様に評価をし、表２に示し
た。Comparative Examples 1 to 4 In Example 1, the degree of condensation of the reaction was 2 ° C. and 40, respectively.
An amino resin solution was obtained in the same manner as in Example 1 except that the reaction was allowed to proceed to 50 ° C, 50 ° C, and 60 ° C. The solid content and condensation degree of each resin are 50% by weight, 2 ° C and 50% by weight, respectively.
-It was 40 degreeC, 50 weight% -50 degreeC, 50 weight% -60 degreeC. Hereinafter, the evaluation was performed in the same manner as in Example 1 and shown in Table 2.

【００２０】[0020]

【表１】 (注) ＰＬ：ポットライフ。 ＵＦ：尿素・ホルムアル
デヒド樹脂。ＰＶＡｃ：酢酸ビニル樹脂エマルジョン。
縮合度：単位 ℃。 強度：単位 kgf/cm²。[Table 1] (Note) PL: Pot life. UF: Urea / formaldehyde resin. PVAc: Vinyl acetate resin emulsion.
Degree of condensation: Unit: ° C. Strength: Unit kgf / cm ² .

【００２１】[0021]

【表２】 [Table 2]

【００２２】実施例５ ２リットルのフラスコに、３７％ホルムアルデヒド７２
０ｇ、メタノール１９８. ９ｇとメラミン５５９ｇを入
れ、２０％ＮａＯＨ水溶液によりｐＨを１０〜１３に調
整し、温水浴にて８０〜９０℃に保ち、縮合度が２０℃
になったところで速やかに常温になるまで冷却した。こ
のアミノ樹脂液の固形分は５８重量％であり、縮合度は
２０℃であった。以下、実施例１と同様に相溶性ＳとＰ
Ｌと合板接着力を調べた。その結果を表３に示す。Example 5 A 2 liter flask was charged with 72% 37% formaldehyde.
0 g, 198.9 g of methanol and 559 g of melamine were added, the pH was adjusted to 10 to 13 with a 20% aqueous NaOH solution, the temperature was maintained at 80 to 90 ° C in a warm water bath, and the degree of condensation was 20 ° C.
When it became, it was quickly cooled to room temperature. The solid content of this amino resin liquid was 58% by weight, and the degree of condensation was 20 ° C. Hereinafter, as in Example 1, the compatibility S and P
The adhesive force between L and plywood was examined. The results are shown in Table 3.

【００２３】実施例６、７ 実施例３において、合成樹脂エマルジョンを住友化学
（株）製エチレン酢酸ビニル樹脂エマルジョン「Ｓ−４
６０」（商品名、固形分約６０％、ｐＨ約４、粘度約６
５００ＣＰ／２５℃）または三井東圧化学（株）製のス
チレン・ブタジエン共重合樹脂エマルジョン「ストラク
トボンドＳＢ−１０２１」（商品名、固形分約４９％、
ｐＨ約４、粘度約７０ＣＰ／２５℃）を使用した以外
は、同様の評価を行った。その結果を表３に示す。Examples 6 and 7 In Example 3, the synthetic resin emulsion was replaced by Sumitomo Chemical Co., Ltd. ethylene vinyl acetate resin emulsion "S-4".
60 "(brand name, solid content about 60%, pH about 4, viscosity about 6
500 CP / 25 ° C.) or a styrene-butadiene copolymer resin emulsion “Structobond SB-1021” manufactured by Mitsui Toatsu Chemicals, Inc. (trade name, solid content about 49%,
The same evaluation was performed except that a pH of about 4 and a viscosity of about 70 CP / 25 ° C.) were used. The results are shown in Table 3.

【００２４】[0024]

【表３】 (注) ＭＦ：メラミン・ホルムアルデヒド樹脂。ＥＶ
Ａ：エチレン・酢酸ビニル樹脂エマルジョン。ＳＢＲ：
スチレン・ブタジエン共重合樹脂エマルジョン。[Table 3] (Note) MF: Melamine / formaldehyde resin. EV
A: Ethylene / vinyl acetate resin emulsion. SBR:
Styrene / butadiene copolymer emulsion.

【００２５】[0025]

【発明の効果】以上に明らかなように、本発明の接着剤
はアミノ樹脂と合成樹脂エマルジョンとが均一に混合し
ており、ポットライフも十分であり、むらのない良好な
接着力が得られる。As is apparent from the above, the adhesive of the present invention is obtained by uniformly mixing the amino resin and the synthetic resin emulsion, has a sufficient pot life, and can obtain good adhesive strength without unevenness. .

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 縮合度が５〜３０℃であるアミノ樹脂
と合成樹脂エマルジョンからなることを特徴とするエマ
ルジョン−アミノ樹脂系接着剤。1. An emulsion-amino resin adhesive, comprising an amino resin having a degree of condensation of 5 to 30 ° C. and a synthetic resin emulsion.