CN100398579C

CN100398579C - Method for preparing colourless resol

Info

Publication number: CN100398579C
Application number: CNB2006100702033A
Authority: CN
Inventors: 王志玲; 王元秀; 任一萍
Original assignee: University of Jinan
Current assignee: Jinan University; University of Jinan
Priority date: 2006-11-15
Filing date: 2006-11-15
Publication date: 2008-07-02
Anticipated expiration: 2026-11-15
Also published as: CN1970596A

Abstract

The invention discloses a making method of leuco bakelite A in the chemical additive technical domain, which comprises the following steps: stirring phenol, metal chelant and sodium hydroxide; heating to 60-75deg.c; adding formaldehyde solution; heating to 90-95 deg.c; insulating 40-50min; cooling to 70-80 deg.c; adding residual phenol; adjusting pH value through 40% sodium hydroxide solution; insulating; acidifying; cooling; discharging.

Description

A kind of method for preparing colourless resol

Technical field

The present invention relates to a kind of method for preparing colourless resol, belong to chemical sizing agent technical field.

Background technology

The polycondensation product of phenols and aldehydes is commonly referred to as resol, resol generally is meant the resin that is obtained through polycondensation by phenol and formaldehyde, because the resol raw material is inexpensive relatively, synthesis technique is simple, and have outstanding instantaneous high temperature resistant ablative behind the curable adhesive layer, glue interface cohesive strength height, glue-line is water-fast, heat-resisting, wear-resisting, chemical stability is good, resin itself has the leeway of extensive modification again, so resol is widely used in the manufacturing of matrix materials such as wood-processing industry, glass filament reinforced plastics and carbon fiber reinforced plastics.

The synthetic need of resol carry out under the condition of acid or base catalysis, under the condition of acid or base catalysis, phenol at first generates hydroxymethyl phenol with formaldehyde generation addition reaction, the hydroxymethyl phenol that generates continues and other phenol or the phenyl ring effect in the hydroxymethyl phenol molecule, borrows methene key and methylene ether link, and further polycondensation generates linear structure, the ratio of control phenol and formaldehyde, can generate the line style resin that contains the methylol active group, promptly thermoset resol claims resole again.The synthetic rule of following the three-dimensional polycondensation reaction of resol, when the synthetic controlling factors such as temperature of the type of the ratio of phenol and formaldehyde, catalyzer and reaction not at that time, the resin that contains the methylol active group then continues further polycondensation, forms not molten, insoluble build cured resin with three-dimensional net structure.

With phenol and formaldehyde is raw material, the synthetic resole of base catalysis is normal the employing, many mineral alkalis, as sodium hydroxide, potassium hydroxide, hydrated barta, ammoniacal liquor etc. all can be used as this catalyst for reaction, sodium hydroxide is inexpensive, and catalysis institute synthetic resol good water solubility, therefore, the research of sodium hydroxide catalytic preparation resole and application are at most, sodium hydroxide belongs to one of highly basic, with sodium hydroxide catalysis, the conventional resole of synthetic alkalescence under strong alkaline condition, outward appearance is the transparent even mucus of sorrel, with sodium hydroxide catalysis, the conventional resole of synthetic weakly alkaline under weak basic condition, outward appearance is the transparent even mucus of reddish-brown, no matter be sorrel or reddish-brown resol, often cause prepared matrix material color burn, this has limited the application of resol in the light decorative composite material of preparation.

Summary of the invention

The objective of the invention is to: remedy the deficiencies in the prior art, a kind of method for preparing colourless resol is provided.

Preparation colourless resol of the present invention may further comprise the steps:

1. in reactor, add the phenol of 25 weight parts while stirring, add the metal chelator of 0.055～0.065 weight part, the adding weight percent is 40% sodium hydroxide solution 3.3～4.5 weight parts;

2. be heated to 60～75 ℃, the adding weight percent is 37% formaldehyde solution 52～69 weight parts;

3. in 20～30min, temperature is risen to 90～95 ℃, insulation 40～50min;

4. be cooled to 70～80 ℃, add the phenol of 5 weight parts again;

5. be that the pH value of 40% sodium hydroxide solution regulator solution is 8～10 with weight percent, keep 70～80 ℃, be reduced to the level that needs up to formaldehyde content;

6. being acidified to pH value with organic acid is 4～6, is cooled to 35～45 ℃, discharging.

Described metal chelator is selected from one of following or combination: citric acid, EDTA, tartrate.

Described organic acid is selected from one of following: M-nitro benzoic acid, xitix, Whitfield's ointment, citric acid, p-methyl benzenesulfonic acid, Phenylsulfonic acid.

The resole of present invention is water white water soluble liq, and pH value is 4～6; Viscosity is 100～260mPa.s; Content of free aldehyde is 0.3% smaller or equal to the weight percentage ratio; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 600～950, and dispersion index is 2.0～2.8; Period of storage is 20～30 days; In period of storage, the viscosity of resol increases, but k value is less than 650mPa.s.

The resole of present invention exists with slightly acidic viscous fluid form, and compared with prior art, the resole of the present invention's preparation is water white, thereby this resole can be applicable in the preparation of light decorative composite material; Because of its viscosity is low, make spraying matrix material starting material carry out easily; Because of its pH value is 4～6, the slightly acidic of this resol has katalysis to the thermofixation of resin, during with composite wooden material starting material blend hot pressing, keeps conventional hot pressing temperature, and hot pressing time shortened than the conventional hot-press time.

Embodiment

Below in conjunction with embodiment the present invention is further described, but protection scope of the present invention is not limited to embodiment.

Embodiment 1:

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.055kg, the adding weight percent is 40% sodium hydroxide solution 3.9kg; Be heated to 65 ℃, the adding weight percent is 37% formaldehyde solution 55kg; In 20min, temperature is risen to 90 ℃, insulation 50min; Be cooled to 80 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 9, keeps 80 ℃, when formaldehyde content is reduced to weight percent 0.3%; With xitix acidifying to the pH value of resin is 5.0, is cooled to 40 ℃, discharging.

The colourless resol of current preparation is transparent water soluble liq, and pH value is 5.0; Viscosity is 156mPa.s; The content of free aldehyde weight percent is 0.3%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 695, and dispersion index is 2.5; When period of storage was 21 days, the viscosity of resol increased to 583mPa.s.

Embodiment 2:

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.055kg, the adding weight percent is 40% sodium hydroxide solution 3.3kg; Be heated to 70 ℃, the adding weight percent is 37% formaldehyde solution 65kg; In 25min, temperature is risen to 94 ℃, insulation 43min; Be cooled to 70 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 8.5, keeps 75 ℃, when the content of formaldehyde is reduced to weight percent when being 0.2%, is 6 with citric acid acidifying to the pH value of resin, is cooled to 45 ℃, discharging.

The colourless resol of current preparation is transparent water soluble liq, and pH value is 6; Viscosity is 128mPa.s; The content of free aldehyde weight percent is 0.2%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 630, and dispersion index is 2.7; When period of storage was 25 days, the viscosity of resol increased to 642mPa.s.

Embodiment 3:

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.015kg, the tartrate of 0.040kg, the adding weight percent is 40% sodium hydroxide solution 4.5kg; Be heated to 75 ℃, the adding weight percent is 37% formaldehyde solution 65kg; In 28min, temperature is risen to 92 ℃, insulation 45min; Be cooled to 75 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 9, keeps 75 ℃, when the content of formaldehyde is reduced to weight percent when being 0.3%; With xitix acidifying to pH value is 4.5, is cooled to 40 ℃, discharging.

The colourless resol of current preparation is transparent water soluble liq, pH value 4.5; Viscosity is 243mPa.s; The content of free aldehyde weight percent is 0.3%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 920, and dispersion index is 2.2; When period of storage was 29 days, the viscosity of resol increased to 648mPa.s.

Embodiment 4:

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.005kg, the citric acid of 0.060kg, the adding weight percent is 40% sodium hydroxide solution 4.5kg; Be heated to 75 ℃, the adding weight percent is 37% formaldehyde solution 65kg; In 28min, temperature is risen to 92 ℃, insulation 45min; Be cooled to 75 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 9, keeps 75 ℃, when the content of formaldehyde is reduced to weight percent 0.25%; Being acidified to pH value with M-nitro benzoic acid is 4.5, is cooled to 40 ℃, discharging.

The resole of current preparation is water white water soluble liq, and pH value is 4.5; Viscosity is 180mPa.s; The content of free aldehyde weight percentage is 0.25%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 744, and dispersion index is 2.1; When period of storage was 28 days, the viscosity of resol increased to 582mPa.s.

Embodiment 5

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.020kg, the tartrate of 0.035kg, the adding weight percent is 40% sodium hydroxide solution 4.5kg; Be heated to 60～75 ℃, the adding weight percent is 37% formaldehyde solution 68kg; In 24min, temperature is risen to 93 ℃, insulation 45min; Be cooled to 80 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 10, keeps 80 ℃, and when formaldehyde content was reduced to weight percent 0.3%, being acidified to pH value with Whitfield's ointment was 5, was cooled to 40 ℃, discharging.

The colourless resol of current preparation is transparent water soluble liq, and pH value is 5; Viscosity is 163mPa.s; The content of free aldehyde weight percent is 0.3%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 825, and dispersion index is 2.6; When period of storage was 26 days, the viscosity of resol increased to 645mPa.s.

Embodiment 6

In reactor, add the phenol of 25kg while stirring, add the EDTA of 0.055kg, the adding weight percent is 40% sodium hydroxide solution 3.5kg; Be heated to 65 ℃, the adding weight percent is 37% formaldehyde solution 65kg; In 26min, temperature is risen to 93 ℃, insulation 45min; Be cooled to 75 ℃, add the phenol of 5kg again; The pH value that with weight percent is 40% sodium hydroxide solution regulator solution is 9.5, keeps 78 ℃, and when formaldehyde content was reduced to weight percent 0.25%, being acidified to pH value with p-methyl benzenesulfonic acid was 6, was cooled to 40 ℃, discharging.

The colourless resol of current preparation is transparent water soluble liq, and pH value is 6; Viscosity is 106mPa.s; The content of free aldehyde weight percent is 0.25%; The number-average molecular weight that adopts gel permeation chromatography (GPC) to record resin is 707, and dispersion index is 2.3; When period of storage was 30 days, the viscosity of resol increased to 596mPa.s.

Claims

1. method for preparing colourless resol is characterized in that being undertaken by following step:

1. in reactor, add the phenol of 25 weight parts while stirring, add the EDTA of 0.055～0.065 weight part, the adding weight percent is 40% sodium hydroxide solution 3.3～4.5 weight parts;

3. in 20～30min, temperature is risen to 90～95 ℃, insulation 40～50min;

4. be cooled to 70～80 ℃, add the phenol of 5 weight parts again;

2. a kind of method for preparing colourless resol according to claim 1 is characterized in that described organic acid, is selected from one of following: M-nitro benzoic acid, xitix, Whitfield's ointment, citric acid, p-methyl benzenesulfonic acid, Phenylsulfonic acid.