CN105199312A - Neutral phenolic foam plastic and preparation method thereof - Google Patents

Abstract

The invention relates to a neutral phenolic foamed plastic and a preparation method thereof. The raw material composition includes 100 parts of expandable phenolic resin, 10-25 parts of compound alkali metal salt, 3-8 parts of surfactant, 4-10 parts of foam Foaming agent and 15 to 25 parts of organic acid curing agent. The formula is reasonable, the preparation process is simple, the cost is low, the reaction between the composite alkali metal salt and the organic acid curing agent is slow, and in the foaming and curing stage, the curing effect of the acid curing agent will not be hindered, and the preparation of the composite alkali metal salt is simple and convenient. No complicated processing is required; the prepared phenolic foam not only retains the low thermal conductivity and high flame retardancy properties of traditional acidic phenolic foam, but also the prepared phenolic foam is neutral and will not damage the Corrosion of building surfaces or metals in contact with it.

Description

A kind of neutral phenolic foam plastic and preparation method thereof

technical field

The invention relates to a phenolic foamed plastic, in particular to a neutral phenolic foamed plastic and a preparation method thereof.

Background technique

Phenolic foam is widely used in the field of building insulation because of its excellent thermal insulation and flame retardancy. In the preparation process of phenolic foam, the phenolic resin, surfactant, foaming agent and filler are generally mixed uniformly first, and then the inorganic acid or organic acid is used as the resin curing agent to foam and cure at a certain temperature. The acid is strong, and it is corrosive to the metal in contact with it or some acid-resistant surfaces during use. After long-term use, it is easy to cause damage to the contact surface of the material.

In the patent whose publication number is CN1566206A, an alkaline foaming agent, including sodium carbonate, sodium bicarbonate, magnesium carbonate or sodium phosphate, is used to replace the traditional organic foaming agent, and the acid-base neutralization reaction is used to make the prepared phenolic foam close to Neutral, but in the actual preparation process, after the acid curing agent is added, it is too late to fully stir, the alkaline foaming agent will react with the acid immediately, release heat and generate bubbles, and the foaming process is difficult to control.

In the patent with the publication number CN102558757A, alkaline slow-release microcapsules are added, and the alkali metal salt released from the capsules is used to neutralize the residual acid in the phenolic foam to obtain a neutral phenolic foam. A layer of capsules is wrapped on the surface of the alkali metal particles. In order to fully disperse in the phenolic foam, the particle size of the alkaline slow-release microcapsules must be small enough, the process is complicated, and the preparation cost of the phenolic foam is also increased.

In the patent with the publication number CN102286188A, a thermoplastic phenolic resin is mixed with a thermosetting phenolic resin, the thermoplastic phenolic resin is cured with hexamethylenetetramine, a small amount of acid is added to cure the thermosetting phenolic resin, and aluminum hydroxide is added to slowly neutralize the residual acid. Obtain neutral phenolic foam. It takes a long time to use hexamethylenetetramine to cure thermoplastic phenolic resin at normal temperature and pressure, and hexamethylenetetramine is easy to react with acid curing agent.

To sum up, there is an urgent need for a new type of neutral phenolic foam with easy control of the operation process, excellent physical properties, easy scale production and low cost.

Contents of the invention

The purpose of the present invention is to provide a kind of neutral phenolic foamed plastics and preparation method thereof, solve the problem that the acidity of the foam itself causes corrosion to the metal or alkaline cement building surface that contacts with it during the use of traditional phenolic foam, overcome the prior art In order to prepare neutral phenolic foam plastics, use alkaline foaming agent instead of traditional foaming agent or add alkaline slow-release microcapsules to the formula or use hexamethylenetetramine to cure thermoplastic phenolic resin. Difficult to control the process, high cost and long time-consuming and other technical problems.

In order to realize the above-mentioned technical purpose, the present invention adopts following technical scheme:

A kind of neutral phenolic foamed plastics, it is characterized in that, contained component and the weight ratio of each component are:

100 parts of expandable phenolic resin;

10-25 parts of compound alkali metal salt;

3-8 parts of surfactant;

Foaming agent 4 to 10 parts;

15-25 parts of organic acid curing agent.

Among them, as a preferred technical solution of the present invention, the molar ratio of phenol to formaldehyde in the expandable phenolic resin is 1.5-2.0, the resin viscosity is 3000-5000 cps at 25°C, and the resin activation temperature is 80-100°C.

Preferably, the composite alkali metal salt is formed by mixing at least two of barium carbonate, trisodium phosphate, anhydrous sodium acetate or sodium lactate pentahydrate, wherein when barium carbonate is used, its mass accounts for 60% to 80% of the total mass. %.

Further preferably, the surfactant is one or a mixture of Tween-80, Tween-60 or PEG-25.

More preferably, the blowing agent is one or a mixture of cyclohexane, petroleum ether or n-pentane.

Further preferably, the organic acid curing agent is one or a mixture of p-toluenesulfonic acid, benzenesulfonyl chloride or phenolsulfonic acid.

The present invention also provides the preparation method of above-mentioned neutral phenolic foam: it is characterized in that, the steps are:

Step 1. Add all the expandable phenolic resin, surfactant and foaming agent into the reaction vessel according to the formula composition and mix them evenly;

Step 2, adding a compound alkali metal salt and an organic acid curing agent into the reaction vessel according to the formula composition, and stirring at a high speed to form a mixture;

Step 3, inject the evenly stirred mixture into the foaming mold;

Step 4: Put the mold in an environment of 60°C-80°C to react for 15-60 minutes, and then the neutral phenolic foam plastic is produced.

Compared with prior art, the technical advantage of the present invention is:

1. The phenolic foam prepared by the present invention not only retains the low thermal conductivity and high flame-retardant performance of the traditional acidic phenolic foam, but also the prepared phenolic foam is neutral, and will not be harmful to the contact with it during use. Corrosion of building surfaces or metals;

2. The compound alkali metal salt added in the preparation process of the phenolic foam in the present invention reacts slowly with the organic acid curing agent, and in the foaming and curing stage, it will not hinder the curing of the acid curing agent, and the compound alkali The metal salt is easy to make and does not require complicated processing;

3. The preparation process is simple, easy to operate, short in time and low in cost.

Detailed ways

The principles and features of the present invention will be described below in conjunction with specific embodiments, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Wherein the raw material ratio of the expandable phenolic resin in the embodiment is: 100 parts of phenol, 62 parts of solid formaldehyde, 0.2 part of sodium hydroxide, 10 parts of 1,4-butanediol, and 5 parts of urea.

The preparation method of expandable phenolic resin: at room temperature, add phenol, solid formaldehyde and sodium hydroxide to a three-necked flask with a condenser and a thermometer according to the formula, heat up to 80°C, keep it warm for 30 minutes, and then heat up to 90°C , keep warm for 1 hour, cool down to 70°C, add 1,4-butanediol and urea, use p-toluenesulfonic acid to neutralize to a pH value of 6.5-7.0, cool down to room temperature, and refrigerate for later use.

Example 1:

The weight proportion of each component of neutral phenolic foam plastics is:

Expandable phenolic resin: 100 parts;

Surfactant: Tween-80, 5 parts;

Foaming agent: n-pentane, 6 parts;

Composite alkali metal salt: 15 parts, including 12 parts of barium carbonate and 3 parts of anhydrous sodium acetate;

Curing agent: p-toluenesulfonic acid, 18 parts.

Preparation process: at room temperature, mix expandable phenolic resin, surfactant and foaming agent according to the composition of the formula, stir evenly, then add complex alkali metal salt and curing agent, stir evenly at high speed, and immediately pour the mixture into the mold , put the mold into an oven at 75°C, keep it for 25 minutes, and take out the phenolic foam from the mold to obtain a foam density of 45kg/m ³ .

Example 2:

The weight proportion of each component of neutral phenolic foam plastics is:

Expandable phenolic resin: 100g;

Surfactant: Tween-60, 6g;

Foaming agent: petroleum ether, 6.5g;

Compound alkali metal salt: 18g, including 15g of barium carbonate and 3g of sodium lactate pentahydrate;

Curing agent: phenolsulfonic acid, 18g.

The preparation process is the same as that in Example 1. After testing, a phenolic foam with a density of 48kg/ ^m3 was obtained.

Example 3:

The weight ratio of each component of the phenolic foam plastic is:

Expandable phenolic resin: 100g;

Surfactant: PEG-25, 4g;

Foaming agent: cyclohexane, 4.5g;

Compound alkali metal salt: 20g, including 15g of barium carbonate, 3g of anhydrous sodium acetate, and 2g of trisodium phosphate;

Curing agent: phenolsulfonic acid, 20g.

The preparation process is the same as that in Example 1. After testing, a phenolic foam with a density of 47kg/ ^m3 was obtained.

Example 4:

The weight proportion of each component of neutral phenolic foam plastics is:

Expandable phenolic resin: 100g;

Surfactant: Tween-80, 4g;

Foaming agent: n-pentane, 6g;

Compound alkali metal salt: 15g, including 10g of barium carbonate, 4g of sodium lactate pentahydrate, and 1g of trisodium phosphate;

Curing agent: 10g of toluenesulfonic acid, 10g of phenolsulfonic acid.

The preparation process is the same as in Example 1, after testing, the obtained density is 46kg/m ³ phenolic foam

Comparative example:

At room temperature, use 100g of expandable phenolic resin and 4g of surfactant Tween-80 to mix, add 6g of pentane and mix evenly, add 20g of curing agent, 10g of toluenesulfonic acid and phenolsulfonic acid in the curing agent . After stirring evenly, pour it into the mold immediately, put the mold into an oven, bake at 70°C for 25 minutes, take out the phenolic foam from the mold, and test the density, pH value, thermal conductivity, compressive strength and oxygen index of the phenolic foam. Contrast Table 1 is the detection result of embodiment and comparative example.

The performance contrast table of table 1 embodiment phenolic foamed plastics and comparative example common phenolic foamed plastics

Analysis table 1, the physical property of the phenolic foam plastic prepared by the method of the present invention is excellent, and the acidity of foam is obviously improved, is conducive to the bonding of phenolic foam with other material surfaces during use, and can not cause other material surfaces corrosion.

Among them, the test method for testing the performance of phenolic foam plastics is as follows:

(1) Density

The present invention uses the method specified in GB/T6343-2009 Determination of the apparent density of foamed plastics and rubber for testing.

(2) PH value

Take some phenolic foam boards, grind them through a 60-mesh sieve, weigh 2 g of the sieved phenolic foam powder, put them into 100 g of distilled water (the pH value of distilled water is 7.0), stir at 20°C for 24 hours, and then filter the powder , Test the pH of the filtrate with a pH meter.

(3) Thermal conductivity

The present invention adopts the method specified in GB/T10294-2008 Determination of Steady-state Thermal Resistance of Thermal Insulation Materials and Its Relevant Properties by Protective Plate Method.

(4) Oxygen index

The present invention adopts the method specified in GB/T2406.2 Determination of Combustion Behavior by Oxygen Index Method for Plastics Part 2: Room Temperature Test.

(5) Compressive strength

The present invention adopts the determination of GB/T8813-2008 compression properties of rigid foamed plastics.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (7)

1. a neutral phenol formaldehyde foam plastic, is characterized in that, the weight proportion of contained component and each component is:

Expandable phenolic resin 100 parts;

Composite alkali metal salt 10 ~ 25 parts;

3 ~ 8 parts, tensio-active agent;

Whipping agent 4 ~ 10 parts;

15 ~ 25 parts, organic acid solidifying agent.

2. neutral phenol formaldehyde foam plastic according to claim 1, is characterized in that: in described expandable phenolic resin, the mol ratio of phenol and formaldehyde is 1.5 ~ 2.0, and resin viscosity is 3000 ~ 5000cps(25 DEG C), resin activity temperature is 80 ~ 100 DEG C.

3. neutral phenol formaldehyde foam plastic according to claim 1, is characterized in that: described composite alkali metal salt is mixed by least two kinds in barium carbonate, tertiary sodium phosphate, anhydrous sodium acetate or five hydration Sodium.alpha.-hydroxypropionates.

4. neutral phenol formaldehyde foam plastic according to claim 1, is characterized in that: described tensio-active agent is one or more the mixture in tween-80, Tween-60 or PEG-25.

5. neutral phenol formaldehyde foam plastic according to claim 1, is characterized in that: described whipping agent is one or more the mixture in hexanaphthene, sherwood oil or Skellysolve A.

6. neutral phenol formaldehyde foam plastic according to claim 1, is characterized in that: described organic acid solidifying agent is one or more the mixture in p-methyl benzenesulfonic acid, benzene sulfonyl chloride or phenol sulfonic acid.

7. the preparation method of the neutral phenol formaldehyde foam plastic according to claim 1 ~ 6 any one: it is characterized in that, concrete steps are:

Step one, whole expandable phenolic resins, tensio-active agent and whipping agent added reaction vessel mixing according to formula composition, stir;

Step 2, in reaction vessel, add composite alkali metal salt and organic acid solidifying agent according to formula composition, high-speed stirring is even, forms compound;

Step 3, the compound injection foaming mould that will stir;

Step 4, mould inserted in 60 ~ 80 DEG C of environment and react 15 ~ 60min, be i.e. obtained neutral phenol formaldehyde foam plastic.