CN100503690C - A kind of two-component catalyst that can be used for cyanate ester curing reaction and preparation method thereof - Google Patents

Abstract

The invention discloses a bi-component organic tin compound catalyst and making method, which is applied to fix cyanate resin, wherein the catalyst consists of organic tin compound and reacting micromolecular compound; the molecular formula of organic tin compound is (H9C4)2Sn(NCO-R-OCN)2, which displays active diluent to form polymer at solidifying time of cyanate resin; two components are stirred under 40-80 deg. c for 15-25min, which are cooled to indoor temperature.

Description

A kind of two-component catalyst that can be used for cyanate ester curing reaction and preparation method thereof

technical field

The invention belongs to the field of chemical industry and relates to a catalyst, especially a catalyst which can be used for curing reaction of cyanate resin.

Background technique

Cyanate resin is a kind of thermosetting resin, which has good heat resistance, mechanical properties, dielectric properties and moisture and heat stability. As a matrix resin for the preparation of high-performance resin-based composite materials, cyanate esters and their composite materials can be used as structural materials, wave-transmitting materials, adhesive materials, dielectric functional materials, etc. in aerospace, electronic information and other fields.

However, pure cyanate ester is difficult to heat-cure, that is, without an external catalyst, its heat-curing reaction is slow and difficult. Therefore, in order to make the cyanate resin easy to heat-cure, a catalyst must be added to the resin system to promote its curing reaction.

The currently known compounds that can catalyze the thermal curing reaction of cyanate esters mainly include the following categories: compound catalysts containing active hydrogen (such as phenol, amine, imidazole, etc.), transition metal salt/nonylphenol mixed catalysts, UV-activated catalysts and organotin compound catalysts, etc. In practical application, it is found that the catalyst has a great influence on the properties of cyanate ester cured resin and its composite materials.

Although the compound containing active hydrogen can catalyze the thermal curing reaction of cyanate ester, its dosage is large, and it can also react with cyanate ester monomer to form imine by-products with poor heat resistance, which reduces the heat resistance of cured resin. Stability, generally not used alone.

In US 4,608,434, it is reported that the mixed catalyst system of transition metal salt (zinc, tin, copper, cobalt, etc. octoate, naphthenate, acetylacetonate, etc.) and nonylphenol has a certain effect on the curing reaction of cyanate High catalytic activity. The addition of nonylphenol, on the one hand, plays a solubilizing role for transition metal salts, and on the other hand, it is also a co-catalyst. However, the catalytic selectivity of this type of catalyst is poor. While catalyzing the curing reaction of cyanate ester, the transition metal salt can catalyze the thermal decomposition reaction and hydrolysis reaction of polycyanate ester at a higher temperature, which will affect the curing reaction of cyanate ester cured resin. and adversely affect the performance of its composite materials.

In US 5,215,860, a class of organic transition metal complex catalysts with UV light activity was reported. It is mainly cyclopentadiene carbonyl metal complex, which is firstly mixed with cyanate monomer and reacts with cyanate functional group to replace carbonyl under ultraviolet light irradiation, and generates a catalyst active component, and then uses this catalyst activity The component catalyzes the curing reaction of the cyanate ester. This type of catalyst has good catalytic activity and selectivity, but its catalytic activity is greatly affected by the preparation process, that is, the catalytic activity varies greatly depending on the intensity and time of ultraviolet radiation, and the degree of reaction is difficult to control. At the same time, the cyclopentadienyl carbonyl metal complex is expensive, which is not conducive to its popularization and application.

An organotin compound catalyst (H ₉ C ₄ ) ₂ Sn(NCO-R-OCN) ₂ , which can be prepared by a simple and controllable reaction from commercially available reagents at an affordable price, has high catalytic activity and Selectivity, at the same time, it has good miscibility with cyanate ester monomers, and does not need to add co-solvents or stabilizers. Its characteristic structure can be expressed as:

(H ₉ C ₄ ) ₂ Sn(NCO-R-OCN) ₂ (NCO-R-OCN is a cyanate monomer, and the R group depends on the structure of the cyanate monomer used)

The component can be prepared according to the method described in the literature (Wenfeng Li, Guozheng Liang, Wenli Xin, Trizane Reactionof Cyanate Ester Resin Systems Catalyzed by Organic Tin Compound: Kinetics and Mechanism, Polymer International, 2004, 53:869-876). The raw materials used are dibutyltin dilaurate (DBTDL) and cyanate monomers (such as bisphenol A cyanate, bisphenol L cyanate, etc.), and the basic process of its preparation is: 1:2 (mol) Weigh DBTDL and cyanate ester monomers and react at 60-80°C for 20-30 minutes to obtain an organotin compound catalyst.

However, since the amount of the organotin catalyst used is very small, about 50-500*10 ^-6 g of the organotin catalyst [Sn] needs to be added per 1 g of cyanate ester monomer, it is difficult to control its addition amount, which makes it difficult to control in actual use. limit.

Contents of the invention

The purpose of the present invention is to provide a kind of two-component organotin catalyst suitable for curing reaction of cyanate resin. It has high catalytic activity and selectivity, and at the same time, it can be well dissolved and dispersed in cyanate monomer.

Another object of the present invention is to provide a method for preparing a two-component organotin catalyst suitable for curing reaction of cyanate resin.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A two-component catalyst for the curing reaction of cyanate esters, containing an organotin compound and a reactive small molecule compound.

Further, the molecular formula of the organic tin compound is: (H ₉ C ₄ ) ₂ Sn(NCO-R-OCN) ₂ .

The small molecular compound can self-polymerize or copolymerize with cyanate ester to form a high polymer while the cyanate ester monomer is curing.

The small molecular compound is liquid epoxy resin or vinyl compound.

The concentration of the organotin compound in the catalyst is 1-5% by weight.

The concentration of the small molecule compound in the catalyst is 99-95% by weight.

It is used in an amount of 2-5% by weight when catalyzing the curing reaction of cyanate ester.

The organotin compound catalyst and the active small molecular compound are heated and stirred at 40-80° C. for 15-25 minutes.

The composition of two-component organotin compound catalyst, comprises A and B two components:

Component A is an organic tin compound with the molecular formula:

(H ₉ C ₄ ) ₂ Sn(NCO-R-OCN) ₂

Among them, R is a substituent containing a benzene ring, and the specific structure depends on the structure of the cyanate monomer used, usually the easily available bisphenol A (diphenylpropane) type or bisphenol L (diphenylethane) type etc.

Component B is a reactive small molecule compound, including epoxy, vinyl compound, etc. The selection principle of component B is that it is a liquid substance at room temperature, can dissolve component A, can also dissolve itself into cyanate monomer, and can form a macromolecular polymer through polymerization reaction under heating.

Epoxy resins that can be used as component B, such as: E-51 epoxy resin, TDE-85 epoxy resin, etc.

Vinyl compounds that can be used as component B, such as: styrene, divinylbenzene, diallyl phthalate, diallyl isophthalate, etc.

Component B itself does not react chemically with component A, it is added as a diluent for component A, and its purpose is to make component A easy to weigh accurately. During the thermal curing reaction of the cyanate ester monomer, the B component can also undergo a chemical reaction and generate a high molecular polymer, so it is called a reactive diluent in the present invention. For example, epoxy can generate polyether structure through ring-opening polymerization, or react with cyanate ester to generate oxazolone structure, and vinyl compound can generate linear macromolecular polymer through free radical polymerization. In this way, after the cyanate is completely cured, there are no small molecular compounds in the system, and the mechanical and heat resistance properties of the cured product will not be affected.

Calculate the mass of component A by adding [Sn]=50～500*10 ^-6 g to 1 g of catalytic cyanate monomer, and the calculation formula of [Sn] is

Wherein M is the molecular weight of the organotin compound, and the value of M is different according to the difference of the cyanate monomer used in the preparation; 118.7 is the atomic weight of Sn, and W _A is the quality of the A component.

According to 100g of catalytic cyanate ester monomers, 5g of two-component catalyst needs to be added, and the concentration of [Sn]' in the two-component catalyst is:

$<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; sn</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 50</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 500</span>}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 5</span>}}\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; g</span>}$

The addition amount of component B is calculated according to the following formula:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; g</span>}\\ \frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}}{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; sn</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; g</span>}\end{array}\right.$

Where W _A is the mass of component A, and W _B is the mass of component B.

Stir component A (1-5% by weight) and component B (95-99% by weight) under heating conditions of 40-80°C for 15-25 minutes to dissolve and disperse evenly, then naturally cool to room temperature to prepare Two-component organotin compound catalyst.

Temperature and time have no effect on the preparation of the two-component catalyst, as long as the uniform dispersion is achieved. Similarly, the mass ratio of component A and component B only has an effect on the concentration of [Sn], which is finally shown as the difference in the quality of the two-component catalyst added in the "application example".

The two-component organotin catalyst suitable for the curing reaction of cyanate ester resins of the present invention has high catalytic activity and selectivity, can be well dissolved and dispersed in cyanate ester monomers, and is easy to weigh so as to control the dosage .

Description of drawings

Fig. 1 is the DSC collection of illustrative plates of cyanate ester resin (a) is the DSC (differential scanning calorimetry) curve of the cyanate ester monomer that adds two-component organotin compound catalyst, (b) is the cyanate ester monomer that does not add catalyst The DSC (differential scanning calorimetry) curve of the body. After the addition of the catalyst, the maximum exothermic peak of the curing reaction of the cyanate ester monomer decreased from 290°C to 209°C, a decrease of about 80°C, indicating that the catalyst of the present invention has good catalytic activity.

Detailed ways

The present invention uses reactive small molecule compounds as reactive diluents to dilute organotin compounds, making it easier to accurately quantify and weigh. ester copolymerization, so that the mixed catalyst system can play a catalytic role without reducing the performance of the cyanate polymer (introducing a second phase into a high-performance cyanate usually improves the heat resistance, mechanical properties, dielectric properties, etc. electrical performance, etc.). Therefore, the B component as the active diluent does not need to consider its molecular weight, but only calculates its mass (for the convenience of weighing and calculation, for example, 5g can be taken). The temperature (40-80° C.) used in the preparation is only for dissolving and dispersing the organotin compound, and has no influence on its performance. For example, when vinyl compounds are used (low-viscosity liquids at room temperature), the temperature should be lower (40-60°C), and when epoxy (high viscosity) is used, the temperature should be higher (60-80°C).

Preparation of organotin compound (bisphenol A type):

Weigh 11.4g of dibutyltin dilaurate (DBTDL, 0.018mol) and 10.0g of bisphenol A cyanate (BADCy, 0.036mol) in a beaker, and react at 60-80°C for 20-30min to obtain organotin Compound catalyst, [Sn]=0.1g per 1g of organotin compound.

Preparation of organotin compound (bisphenol L type):

Weigh 10.1g of dibutyltin dilaurate (DBTDL, 0.016mol) and 8.5g of 4,4'-dicyanato-diphenylpropane (BEDCy, 0.036mol) in a beaker, and react at 40-70°C for 20 ~30min, the organotin compound catalyst is prepared, [Sn]=0.1g in every 1g of organotin compound.

Example 1:

Weigh 268g of epoxy E-51 resin and place it in a beaker, heat it to 60-80°C in an oil bath, add 10.7g of organotin compound (bisphenol A type), keep the temperature at 60-80°C, and stir for 15min. Heating was stopped, and it was naturally cooled to room temperature to obtain a two-component organotin compound catalyst in the form of light brown viscous liquid. Tin content [Sn]=0.003845g per 1g of two-component catalyst.

Example 2:

Except that epoxy E-51 resin takes by weighing 536g, other is identical with embodiment 1. Tin content [Sn]=0.001922g per 1g of two-component catalyst.

Example 3:

Weigh 245g of diallyl isophthalate and place it in a beaker, heat it to 40-60°C in an oil bath, add 5.5g of organotin compound (bisphenol L type), continue to maintain the temperature at 40-60°C, and Stir for 15 minutes, stop heating, and naturally cool to room temperature to obtain a light brown, low-viscosity liquid two-component organotin compound catalyst. Tin content [Sn]=0.00221g per 1g of two-component catalyst.

Application example:

Weigh 100g of bisphenol A type cyanate monomer and place it in a beaker, heat it in an oil bath at 100°C until it melts, add 5g of the two-component organotin compound catalyst prepared in Example 1, stir evenly, and pour it into the pre- In the treated glass mold, vacuum degassing for 10 minutes, then put it into an electronic oven, cure according to the process of 180°C/1h+200°C/2h, and finally cure at 220°C for 2 hours to obtain organotin-catalyzed cyanate Cured resin. The glass transition temperature (Tg) of the cured resin measured by the DMA method was 276°C.

Claims (2)

1, a kind of bicomponent catalyst that is used for the cyanate curing reaction is characterized in that: be made up of organo-tin compound and reactive thinner;

The molecular formula of this organo-tin compound is: (H ₉C ₄) ₂Sn (NCO-R-OCN) ₂, wherein, R is the substituting group that contains phenyl ring, the described substituting group that contains phenyl ring is bisphenol A-type or bis-phenol L type;

This reactive thinner is liquid Resins, epoxy or vinyl compound, and it can autohemagglutination or form superpolymer with the cyanate copolymerization in the cyanate ester monomer curing reaction;

The concentration of this organo-tin compound in catalyzer is 1～5% weight.

2, the described using method that is used for the bicomponent catalyst of cyanate curing reaction of claim 1 is characterized in that: its consumption when the curing reaction of catalysis cyanate is 2～5% weight.