阅读说明：本技术 一种耐黄变的聚乙烯醇缩丁醛树脂及其制备方法和应用 (Yellowing-resistant polyvinyl butyral resin and preparation method and application thereof ) 是由 林家宝 于 2020-04-09 设计创作，主要内容包括：本发明公开了一种耐黄变的聚乙烯醇缩丁醛树脂及其制备方法和应用。这种聚乙烯醇缩丁醛树脂的制备原料包括聚乙烯醇、丁醛和式(Ⅰ)所示结构的化合物：<Image he="438" wi="404" file="DDA0002443922410000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image><Image he="62" wi="130" file="DDA0002443922410000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>这种耐黄变的聚乙烯醇缩丁醛树脂可以应用制备聚乙烯醇缩丁醛胶片或夹层玻璃。本发明制备的聚乙烯醇缩丁醛树脂,在受一定高温后不会发黄,具有抗老化性能和热稳定性能好的优点,可应用于制备PVB胶片以及建筑或汽车的夹层玻璃,市场前景广阔。(The invention discloses a yellowing-resistant polyvinyl butyral resin, and a preparation method and application thereof. The raw materials for preparing the polyvinyl butyral resin comprise polyvinyl alcohol, butyraldehyde and a compound with a structure shown in a formula (I):)

1. A polyvinyl butyral resin resistant to yellowing, characterized in that: the raw materials for preparing the polyvinyl butyral resin comprise polyvinyl alcohol, butyraldehyde and a compound with a structure shown in a formula (I):

in the formula (I), R₁is-C (CH)₃)₃OrR₂Selected from C1-C4 alkyl orR₃Selected from C1-C18 alkyl,m＝1～6，n＝1～19。

2. The yellowing-resistant polyvinyl butyral resin as claimed in claim 1, wherein: the compound with the structure shown in the formula (I) is firstly dissolved in butyraldehyde and then is used for preparing the polyvinyl butyral resin.

3. The yellowing-resistant polyvinyl butyral resin according to claim 1 or 2, wherein: the preparation raw materials of the yellowing-resistant polyvinyl butyral resin comprise, by mass: 50-55 parts of polyvinyl alcohol, 28-35 parts of butyraldehyde and 0.2-1 part of compound with a structure shown in a formula (I).

4. The yellowing-resistant polyvinyl butyral resin as claimed in claim 3, wherein: the raw materials for preparing the polyvinyl butyral resin also comprise 5-8 parts by mass of an acid catalyst and 5-10 parts by mass of alkali.

5. The yellowing-resistant polyvinyl butyral resin as claimed in claim 4, wherein: the acid catalyst is at least one selected from hydrochloric acid, sulfuric acid and phosphoric acid.

6. The yellowing-resistant polyvinyl butyral resin as claimed in claim 4, wherein: the alkali is at least one selected from potassium hydroxide solution, sodium hydroxide solution, potassium carbonate solution, sodium carbonate solution, potassium bicarbonate solution and sodium bicarbonate solution.

7. A method of preparing the yellowing-resistant polyvinyl butyral resin of any one of claims 4 to 6, comprising: the method comprises the following steps:

1) dissolving a compound with a structure shown in a formula (I) in butyraldehyde;

2) adding polyvinyl alcohol into water, heating and dissolving to obtain a PVA solution;

3) cooling the PVA solution, adding an acid catalyst, and then adding the solution prepared in the step 1) to perform condensation reaction;

4) and (3) stabilizing the acetal reaction product, adding alkali for neutralization, washing with water, dehydrating, and drying to obtain the yellowing-resistant polyvinyl butyral resin.

8. The method of claim 7, wherein: the step 3) is specifically as follows: cooling the PVA solution to 7-12 ℃, adding an acid catalyst, and then adding the solution prepared in the step 1) at 10-15 ℃ for condensation reaction.

9. The method of claim 7, wherein: the step 4) specifically comprises the following steps:

keeping the temperature of the acetal reaction product at 10-15 ℃ for 0.5-1.5 hours;

heating to 66-70 deg.c and maintaining for 1-2.5 hr;

adding alkali to adjust the pH value to 3.8-4.5, and keeping the temperature for 0.5-1.5 hours;

washing with water, adding alkali to adjust the pH value to 10-15, and keeping the temperature for 20-40 minutes;

and then washing with water until the pH value is 9-14, dehydrating, and drying to obtain the yellowing-resistant polyvinyl butyral resin.

10. Use of the yellowing-resistant polyvinyl butyral resin according to any one of claims 1 to 6 for producing a polyvinyl butyral sheet or laminated glass.

Technical Field

The invention relates to the technical field of high polymer materials, in particular to anti-yellowing polyvinyl butyral resin and a preparation method and application thereof.

Background

Although the research on polyvinyl butyral (PVB) in China has been started in the last 60 th century, the development speed is slow, the product quality grade is not high, and the research is mainly focused on the fields of coatings, adhesives and the like. With the development of the automobile industry, the building industry and the photovoltaic industry, the demand for high-grade PVB resin is huge, but no factory can produce the PVB resin at home, and the PVB resin is imported. One of the main causes of this is yellowing of PVB. The aging and degradation of PVB, the self-polymerization and oxidation of residual butyraldehyde and the like are reasons for the yellowing of PVB. The PVB resin produced in China can be yellowed in a yellowing experiment.

In recent years, with the rapid development of the building and automobile industry, PVB film is also called PVB film or PVB interlayer. It is the best material for manufacturing laminated safety glass in the world today. The PVB film is made of PVB resin, and the resin is nontoxic, odorless, non-corrosive and non-flammable, has good functions of light transmission, insulativity, weather resistance, wear resistance, water resistance, oil resistance and aging resistance, and has special cohesiveness and light transmission performance for inorganic and organic glass.

The key point of the PVB resin powder is used as a middle film for side-wall laminated glass, the PVB resin powder is required to be developed at a higher environmental temperature (150-200 ℃), particularly, the PVB resin powder is required to be maintained at a high temperature for a longer time period when video interlayer laminated glass is manufactured, and the refining temperature of the epoxy resin is lower (230 ℃), so that the adverse effect of thermal embrittlement on the characteristics of the film in the production process is great, and the phenomena of yellowing, stickiness, hardening and the like can occur when the plastic film is heated for a longer time period.

Disclosure of Invention

In order to overcome the problems of poor aging resistance and thermal stability, yellowing and the like of polyvinyl butyral in the prior art, one aim of the invention is to provide a polyvinyl butyral resin with yellowing resistance, the other aim of the invention is to provide a preparation method of the polyvinyl butyral resin with yellowing resistance, and the other aim of the invention is to provide application of the polyvinyl butyral resin with yellowing resistance. The polyvinyl butyral resin provided by the invention can be baked at 180 ℃ for 60 minutes without yellowing.

The present inventors have surprisingly found, through extensive experimental studies, that yellowing of a polyvinyl butyral resin can be suppressed by adding a phenol derivative having a specific structure.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a yellowing-resistant polyvinyl butyral resin, which is prepared from polyvinyl alcohol (PVA), butyraldehyde and a compound with a structure shown in a formula (I):

in the formula (I), R₁is-C (CH)₃)₃OrR₂Selected from C1-C4 alkyl orR₃Selected from C1-C18 alkyl,m＝1～6，n＝1～19。

Preferably, in the compound of formula (I), R₁is-C (CH)₃)₃OrR₂is-C (CH)₃)₃OrR₃Selected from methyl,Orm is 2, n is 7 or 17.

Further preferably, the compound of formula (i) is selected from the group consisting of:

in the formula (I), R₁Is composed ofR₂Is composed ofR₃Is composed of

In the formula (I), R₁is-C (CH)₃)₃，R₂is-C (CH)₃)₃，R₃Is composed of

In the formula (I), R₁is-C (CH)₃)₃，R₂is-C (CH)₃)₃，R₃Is methyl;

in the formula (I), R₁is-C (CH)₃)₃，R₂is-C (CH)₃)₃，R₃Is composed ofm＝2，n＝7；

In the formula (I), R₁is-C (CH)₃)₃，R₂is-C (CH)₃)₃，R₃Is composed ofm＝2，n＝17。

The compound with the structure shown in the formula (I) adopted by the invention can react with chain-growth free radicals in autoxidation to eliminate the free radicals so as to interrupt the chain reaction, and the compound can be used as a hydrogen donor and a free radical trapping agent. Because 2 strong electron-pushing groups are arranged on the 2 and 6 positions, the compound with the structure shown in the formula (I) also has strong antioxidation effect and can prevent the PVB resin from yellowing due to heating.

Preferably, in the yellowing-resistant polyvinyl butyral resin, the compound with the structure shown in the formula (I) is dissolved in butyraldehyde and then is used for preparing the polyvinyl butyral resin. Further, a solution of a compound having a structure represented by the formula (I) in butylaldehyde is added at the stage of the condensation step for producing a polyvinyl butyral resin.

Preferably, in the yellowing-resistant polyvinyl butyral resin, the polymerization degree of polyvinyl alcohol is 1500 to 2000.

Preferably, in the yellowing-resistant polyvinyl butyral resin, the alcoholysis degree of polyvinyl alcohol is not less than 98%.

Preferably, the preparation raw materials of the yellowing-resistant polyvinyl butyral resin comprise, by mass: 50-55 parts of polyvinyl alcohol, 28-35 parts of butyraldehyde and 0.2-1 part of compound with a structure shown in a formula (I).

Preferably, in the raw materials for preparing the yellowing-resistant polyvinyl butyral resin, the amount of the structural compound represented by formula (i) may be selected from 0.2 parts by mass, 0.5 parts by mass, or 1 part by mass.

Preferably, the raw materials for preparing the yellowing-resistant polyvinyl butyral resin further comprise 5-8 parts by mass of an acid catalyst and 5-10 parts by mass of an alkali.

Preferably, in the yellowing-resistant polyvinyl butyral resin, the acid catalyst is at least one selected from hydrochloric acid, sulfuric acid, and phosphoric acid. In some preferred embodiments of the invention, the acid catalyst is hydrochloric acid. The hydrochloric acid can be diluted hydrochloric acid, and the concentration can be adjusted according to actual needs, for example, diluted hydrochloric acid with the mass concentration of 30-31% (HCl) is adopted, which belongs to the conventional method.

Preferably, in the yellowing-resistant polyvinyl butyral resin, the base is at least one selected from the group consisting of a potassium hydroxide solution, a sodium hydroxide solution, a potassium carbonate solution, a sodium carbonate solution, a potassium hydrogen carbonate solution, and a sodium hydrogen carbonate solution; further preferably, the alkali is at least one selected from a potassium hydroxide solution and a sodium hydroxide solution. In some preferred embodiments of the invention, the base is sodium hydroxide solution (liquid base). The concentration of the sodium hydroxide solution can be adjusted according to actual needs, for example, a sodium hydroxide solution with a mass concentration of 30-32% is adopted, which belongs to the conventional method.

Preferably, the preparation raw materials of the yellowing-resistant polyvinyl butyral resin comprise the following components in parts by mass: 50-55 parts of polyvinyl alcohol, 30-35 parts of butyraldehyde, 7-8 parts of acid catalyst, 8-10 parts of alkali and 0.2-1 part of compound with a structure shown in a formula (I).

In the raw materials for preparing the yellowing-resistant polyvinyl butyral resin, butyraldehyde is n-butyraldehyde.

The invention also provides a preparation method of the yellowing-resistant polyvinyl butyral resin.

A preparation method of the yellowing-resistant polyvinyl butyral resin comprises the following steps:

1) dissolving a compound with a structure shown in a formula (I) in butyraldehyde;

2) adding polyvinyl alcohol into water, heating and dissolving to obtain a PVA solution;

3) cooling the PVA solution, adding an acid catalyst, and then adding the solution prepared in the step 1) to perform condensation reaction;

4) and (3) stabilizing the acetal reaction product, adding alkali for neutralization, washing with water, dehydrating, and drying to obtain the yellowing-resistant polyvinyl butyral resin.

Preferably, in the step 2) of the preparation method, the temperature for heating and dissolving is 95-99 ℃; further preferably, the temperature for heating and dissolving is 97 to 98 ℃.

In step 2) of the method for producing a polyvinyl butyral resin, the concentration of the PVA solution can be adjusted according to the actual circumstances. In some preferred embodiments of the present invention, the PVA solution has a PVA mass concentration of 8% to 9%.

Preferably, the preparation method step 3) is specifically as follows: cooling the PVA solution to 7-12 ℃, adding acid, and then adding the solution prepared in the step 1) at 10-15 ℃ for condensation reaction.

Preferably, the preparation method, step 4), specifically comprises the following steps:

keeping the temperature of the acetal reaction product at 10-15 ℃ for 0.5-1.5 hours;

heating to 66-70 deg.c and maintaining for 1-2.5 hr;

adding alkali to adjust the pH value to 3.8-4.5, and keeping the temperature for 0.5-1.5 hours;

washing with water, adding alkali to adjust the pH value to 10-15, and keeping the temperature for 20-40 minutes;

and then washing with water until the pH value is 9-14, dehydrating, and drying to obtain the yellowing-resistant polyvinyl butyral resin.

Preferably, in the step 4) of the preparation method, the washing is performed by using hot water, the washing frequency can be adjusted according to actual conditions, and the preferable frequency is 9-14 times.

Preferably, in the step 4) of the preparation method, the polyvinyl butyral resin with yellowing resistance is obtained by washing with water until the pH value is 9-14, dehydrating and drying.

Preferably, in step 4) of the preparation method, the dewatering is performed by spin-drying with a centrifuge.

Preferably, in step 4) of the preparation method, the resin is dried until the water content of the resin is 5 wt% or less; further preferably, the drying is carried out until the water content of the resin is 2 wt% or less.

The invention also provides application of the yellowing-resistant polyvinyl butyral resin.

The application of the anti-yellowing polyvinyl butyral resin in preparing a polyvinyl butyral film (PVB film) or laminated glass. The laminated glass can be applied to the fields of buildings or automobiles.

The invention has the beneficial effects that:

the polyvinyl butyral resin prepared by the invention can not yellow after being subjected to a certain high temperature, has the advantages of good ageing resistance and thermal stability, can be applied to preparation of PVB films and laminated glass of buildings or automobiles, and has wide market prospect.

Drawings

FIG. 1 is a graph showing the results of a baking test;

FIG. 2 is a graph showing the results of the inspection of the light transmittance of laminated glass.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials, reagents or apparatus used in the examples and comparative examples were obtained from conventional commercial sources or can be obtained by a method of the prior art, unless otherwise specified. Unless otherwise indicated, the testing or testing methods are conventional in the art.