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CN-122029238-A - Curable composition and cured product

CN122029238ACN 122029238 ACN122029238 ACN 122029238ACN-122029238-A

Abstract

The present invention provides a curable composition which provides a cured product having good handleability and sufficient elongation and strength, and a cured product of the curable composition. The curable composition contains a polymer (A) having a number average molecular weight of 3000 or more and 100000 or less and a reactive silicon group, a compound (B) having a number average molecular weight of 50 or more and less than 3000 and a reactive silicon group, and a reaction catalyst (C), wherein the number of hydrolyzable silyl groups at each 1 end of the polymer (A) is 0.85 or more on average, and the ratio of the number of moles of 2-functional compounds (B2) having 2 hydrolyzable groups and/or hydroxyl groups on a silicon atom to the number of moles of the compound (B) is 50mol% or more.

Inventors

  • OHNISHI Yoshinobu
  • MORIMOTO TAKASHI
  • Haramoto Takahiro
  • WAKABAYASHI KATSUYU

Assignees

  • 株式会社钟化

Dates

Publication Date
20260512
Application Date
20241015
Priority Date
20231012

Claims (9)

  1. 1. A curable composition comprising a polymer (A), a compound (B) and a reaction catalyst (C), wherein, The polymer (A) and the compound (B) have a hydrolyzable silyl group as a reactive silicon group, The number average molecular weight of the polymer (A) is 3000 to 100000, The number average molecular weight of the compound (B) is 50 or more and less than 3000, The number of hydrolyzable silyl groups per 1 end of the polymer (A) is 0.85 or more on average, The ratio of the number of moles of the 2-functional compound (B2) having 2 hydrolyzable groups and/or hydroxyl groups on the silicon atom to the number of moles of the compound (B) is 50mol% or more, The reaction catalyst (C) catalyzes the condensation reaction between the hydrolyzable silyl groups.
  2. 2. The curable composition according to claim 1, wherein, The polymer (a) has a group represented by the following formula (2) as the hydrolyzable silyl group: -OCH 2 CH 2 CH 2 SiR 1 3-a X a (2) In the formula (2), R 1 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms or a triorganosiloxy group represented by R 0 3 SiO-, 3R 0 are hydrocarbon groups having 1 to 20 carbon atoms, 3R 0 may be the same or different, X represents a hydroxyl group or a hydrolyzable group, a is 1, 2 or 3, and when a plurality of R 1 or X exist, a plurality of R 1 or a plurality of X may be the same or different.
  3. 3. The curable composition according to claim 1 or 2, wherein, The reactive silicon group in the polymer (a) has 2 hydrolyzable groups on a silicon atom.
  4. 4. The curable composition according to claim 1 or 2, wherein, The polymer (A) is 1 or more selected from the group consisting of a polyoxyalkylene polymer, a poly (meth) acrylate polymer and a polyisobutylene polymer.
  5. 5. The curable composition according to claim 1 or 2, wherein, The ratio of the mol number of the compound (B2) to the mol number of the compound (B) is 80mol% or more.
  6. 6. The curable composition according to claim 1 or 2, wherein, The number of reactive silicon groups in 1 molecule of the 2-functional compound (b 2) is 1.
  7. 7. The curable composition according to claim 1 or 2, wherein, The ratio of the number of moles of the reactive silicon groups contained in the compound (B) to the number of moles of the reactive silicon groups contained in the polymer (A) is 0.6 or more and less than 4.0.
  8. 8. The curable composition according to claim 1 or 2, wherein, The reaction catalyst (C) comprises a carboxylic acid or a metal salt of a carboxylic acid.
  9. 9. A cured product of the curable composition according to claim 1 or 2.

Description

Curable composition and cured product Technical Field The present invention relates to a curable composition containing a polymer having a reactive silicon group and a cured product thereof. Background Polymers having a silyl group having a hydroxyl group or a hydrolyzable group (hereinafter referred to as "reactive silicon group") on a silicon atom and being in a liquid state at room temperature and use temperature are known as moisture-reactive polymers. The polymer reacts with moisture such as air in the presence of a curing catalyst to form a rubbery cured product having flexibility. Therefore, a polymer having a reactive silicon group is used in many industrial products such as a sealing material, an adhesive, a coating material, a paint, and an adhesive. Organic polymers having reactive silicon groups and a main chain skeleton of polyoxyalkylene, polyacrylate or polyisobutylene have been industrially produced. Such organic polymers are widely used for sealing materials, adhesives, paints, waterproof materials, and the like. Curable compositions such as sealing materials, adhesives, paints, and waterproof materials containing a polymer having a reactive silicon group are required to have various properties such as curability, adhesiveness, handleability, and mechanical properties and waterproof properties of the cured product. Generally, in a curable composition containing a polymer having a reactive silicon group as a main component, a compound having a reactive silicon group is used for the purpose of adjusting the above-described properties. The compound having a reactive silicon group can impart various properties to the curable composition depending on the number of hydrolyzable groups and the type of substituents. For example, vinyltrimethoxysilane is used as a dehydrating agent for suppressing an increase in viscosity that occurs when the curable composition is stored for a long period of time. As the adhesion promoter for improving the adhesion strength to the cured substrate, aminopropyl trimethoxysilane was used. Further, as a physical property improver for improving the hardness of the cured product, phenyltrimethoxysilane is used. In order to react the reactive silicon groups, hydrolysis and formation of siloxane bonds are performed, so-called silanol condensation catalysts are used. As silanol condensation catalysts, organotin compounds having a carbon-tin bond such as dibutyltin bis (acetylacetonate), metal carboxylates such as tin carboxylates, organic salts obtained by combining carboxylic acids with amine compounds, metal complexes such as titanium compounds, and the like have been proposed. Disclosure of Invention Problems to be solved by the invention In the above curable composition containing the reactive silicon group-containing polymer, the reactive silicon group-containing compound, and the silanol condensation catalyst, the structure and composition of each component are adjusted to control the physical properties such as hardness, elongation, and strength of the obtained cured product, thereby providing a curable composition satisfying various required physical properties. In general, in a curable composition containing a polymer having a reactive silicon group as a main component, it is effective to increase the molecular weight of the polymer in order to obtain a soft and sufficiently elongated cured product. However, if a polymer having a large molecular weight is used, the viscosity of the curable composition may be high, and the handleability of the curable composition may be reduced. In addition, a method of reducing the hardness of a cured product while maintaining a low viscosity by using a 2-functional water-containing silicon-based compound in combination with a polymer having a reactive silicon group is also known. However, in this case, the hardness of the cured product may extremely decrease, and the strength of the cured product may decrease. The purpose of the present invention is to provide a curable composition which has good handleability and which can form a cured product having sufficient elongation and strength, and a cured product of the curable composition. Means for solving the problems As a result of intensive studies to solve the above problems, the present inventors have found that a curable composition having good handleability and having both elongation and strength of a cured product can be obtained by combining a polymer having a reactive silicon group and a specific structure, a compound having a reactive silicon group and a specific structure, and a silanol condensation catalyst, and have completed the present invention. Specifically disclosed is a curable composition which contains a polymer (A) having a reactive silicon group and a number average molecular weight of 3000 or more and 100000 or less, a compound (B) having a number average molecular weight of 50 or more and less than 3000 and a reactive silicon group, and a reaction catalyst (C)