JP2005281576A5

JP2005281576A5 -

Info

Publication number: JP2005281576A5
Application number: JP2004099305A
Authority: JP
Filing date: 2004-03-30
Publication date: 2006-06-15
Anticipated expiration: 2024-03-30

Description

（Ａ）重量平均分子量２０，０００〜２５０，０００の共重合体であって、そのガラス転移温度が−３０〜０℃のアクリル系エマルション重合体粒子５０〜７０質量％ならびに
（Ｂ）重量平均分子量２０，０００〜２５０，０００の共重合体であって、そのガラス
転移温度が５〜５０℃のアクリル系エマルション重合体粒子５０〜３０質量％。 (A) A copolymer having a weight average molecular weight of 20,000 to 250,000, and 50 to 70% by mass of acrylic emulsion polymer particles having a glass transition temperature of −30 to 0 ° C. and (B) a weight average molecular weight. 50-30 mass% acrylic emulsion polymer particles having a glass transition temperature of 5-50 ° C., which are 20,000-250,000 copolymers.

まず、（Ａ）低いガラス転移温度の共重合体のアクリル系エマルションとしては、重量平均分子量２０，０００〜２５０，０００の共重合体、好ましくは４０，０００〜２２０，０００、より好ましくは６０，０００〜２００，０００のものであって、そのガラス転移温度は−３０〜０℃、好ましくは−２５〜−５℃のものである。すなわち、重量平均分子量が２０，０００未満では低い制振性を示す状態であり、一方、２５０，０００を越えると相溶性が低下する状態だからである。また、水系制振材は１０〜７０℃の温度範囲にて制振性能を発現するタイプが用いられる。（Ａ）は、おおむね低温側（１０〜４０℃）での制振性能を期待されるが、ガラス転移点が−３０℃未満では、制振性が低く、一方、０℃を越えると、造膜性が低下するからである。 First, the acrylic emulsion copolymer of (A) a low glass transition temperature, the copolymer of Weight average molecular weight 20,000～250,000, preferably 40,000～220,000, more preferably 60 The glass transition temperature is -30 to 0 ° C, preferably -25 to -5 ° C. That is, if the weight average molecular weight is less than 20,000, it is in a state of low vibration damping, whereas if it exceeds 250,000, the compatibility is lowered. Moreover, the type which expresses a damping performance in the temperature range of 10-70 degreeC is used for a water-system damping material. (A) is generally expected to have damping performance on the low temperature side (10 to 40 ° C). However, if the glass transition point is less than -30 ° C, the damping performance is low. This is because the film property is lowered.

（Ｂ）高いガラス転移温度の共重合体のアクリル系エマルションとしては、重量平均分
子量２０，０００〜２５０，０００、好ましくは４０，０００〜２２０，０００、より好ましくは６０，０００〜２００，０００のものであって、そのガラス転移温度は５〜５０℃、好ましくは１０〜４０℃のものである。エマルション（Ａ）および（Ｂ）におけるガラス転移温度の差は５〜８０℃が好ましく、より好ましくは１０〜４０℃である。すなわち、重量平均分子量が２０，０００未満では低い制振性を示す状態であり、一方、２５０，０００を越えると相溶性が低下する状態だからである。また、（Ｂ）は、おおむね４０〜７０℃での制振性能を期待されるが、ガラス転移点が５℃未満では、４０〜７０℃での制振性がカバーできないからであり、一方、５０℃を越えると、造膜性が低下するからである。また、ガラス転移の差が５℃未満では、１０〜７０℃の温度幅をカバーできないからであり、一方、８０℃を越えると、１０〜７０℃の温度幅をカバーできないからである。 The acrylic emulsion (B) high glass transition temperature of the copolymer, Weight average molecular weight 20,000～250,000, preferably 40,000～220,000, more preferably 60,000～200,000 The glass transition temperature is 5 to 50 ° C, preferably 10 to 40 ° C. The difference between the glass transition temperatures of the emulsions (A) and (B) is preferably 5 to 80 ° C, more preferably 10 to 40 ° C. That is, if the weight average molecular weight is less than 20,000, it is in a state of low vibration damping, whereas if it exceeds 250,000, the compatibility is lowered. In addition, (B) is generally expected to have a damping performance at 40 to 70 ° C., but if the glass transition point is less than 5 ° C., the damping performance at 40 to 70 ° C. cannot be covered, It is because film forming property will fall when it exceeds 50 degreeC. Moreover, it is because the temperature range of 10-70 degreeC cannot be covered if the difference of glass transition is less than 5 degreeC, and it is because the temperature range of 10-70 degreeC cannot be covered when it exceeds 80 degreeC.

Claims

A polymer aqueous dispersion comprising two or more polymers having different glass transition temperatures,
The aqueous polymer dispersion is at least the following (A) a polymer having a low glass transition temperature and (B)
An emulsion for an aqueous vibration damping material, comprising a polymer having a high glass transition temperature.
(A) Weight A copolymer of average molecular weight 20,000～250,000, the glass transition temperature of -30 to 0 ° C. acrylic emulsion polymer particles from 50 to 70 wt%
And (B) Weight A copolymer of average molecular weight 20,000～250,000, acrylic emulsion polymer particles 50-30 wt% of the glass transition temperature of 5 to 50 ° C..

The acrylic emulsion (A) has a weight average molecular weight of 40,000 to 220,000, a glass transition temperature of −25 to −5 ° C., and the acrylic emulsion (B) has a weight average molecular weight of 40,000. ~ 220,000 and a glass transition temperature of 10-4
The emulsion for aqueous vibration damping materials according to claim 1, which is at 0 ° C.

The emulsion for aqueous vibration damping materials according to claim 1 or 2, wherein the difference in glass transition temperature between the acrylic emulsions (A) and (B) is 5 to 80 ° C.