JPS58179245A - Photodeterioration preventive for plastics - Google Patents

Abstract

PURPOSE:A photodetrioration preventive that is composed of beta-carboxyvinyl substituted 2,4-dinhydroxybenzophenone, thus sowing high compatibility to and dispersibility in plastics, converting into high molecules by sun light or the like on application to cause no evaporation off and no leaching out into rain water. CONSTITUTION:The objective photoderioration preventive contains a 2,4-dihydroxybenzophenone bearing beta-carboxyvinyl group as a substituent of formula I (one of R1 and R2 is H, and the other is beta-carboxyvinyl or both of them are beta-carboxyvinyl). The compound is obtained, e.g., by suspending zinc chloride in an ethereal solution of p-cyanosuccinic acid of formula II, as a starting compound, passing hydrogen chloride through the solution for 2-3hr and adding resorcin, adding water after the reaction, extracting with ether, then subjecting the product to column chromatography.

Description

[Detailed description of the invention] Akira Honcho! This invention relates to a photodegradation inhibitor for plastics that protects other plastics, such as starch, from the ultraviolet rays of sunlight.

Conventional plastic photodegradation inhibitors and so-called UV-obscuring agents such as L-oxybenzophenone d4 have been poorly developed. However, when plastics containing these UV absorbers are used outside the Kansen line, *outside I! Absorbents have the disadvantage that they escape from plastics and paints through volatilization or dissolution in rainwater, and cannot produce sufficient photodegradation prevention effects.

On the other hand, in order to improve these drawbacks, a 4-molecular-weight UV 11# absorber has been developed, but it has disadvantages in terms of economics. If the fraction LK is less than 5 when blending,
There were drawbacks.

The present invention aims to eliminate these drawbacks by using plastic or! ! When blended into family A, it is a low-molecular compound that has good compatibility with plastics, and when used, it becomes polymer mineralized by ultraviolet rays such as sunlight, and volatilizes during use.
- This is an attempt to prevent dissolution in water and maintain its photodeterioration prevention effect during the mourning period.

The invention has two formulas I. β-carboxyvinyl group i
2,4-dihydroxybenzophenone carboxyvinyl group or both are β-carbo-1'/hinyl groups).

The first step of the method for synthesizing the compound of formula (1) in which R, is -CH=CH-COOH and R, is H will be described below.

In the formula U/] ('Puff 7 Anokyskin powder is used as a starting material, and suspended in I11 lead chloride in the Ena/l bath solution. After passing a bottled water cable through it for 2 to 6 inches, , resorcinol is added. After the completion of the reaction, water is added and the product is extracted using a top-chill. When the product is separated using column I-+? Togelafy, 2.
．． 4-dihydro+no-c-7yL carboxyvinyl-benzophenone is preferred.

One of the β-carboxylic acids, 2,4-dihydroxybe/siphenon, is synthesized in a similar manner.

The 2.4-7 human dibenzophenone conductor of 2L et al. is kneaded by outside the system and becomes a single molecule. If you keep it, two β-ruboxyvinyl groups will meet 2#4-dihydroIffki7
The be/siphenon-conductor also undergoes trimerization and higher molecular weight.

Next time! 2,4-dihydroxy-4'-β of the present invention
-carboxyvinyl-benzophenone and conventionally known 2-
Oxy.

0.6 each of 4-octyloxybenzo-7dinone
It shows the residual elongation when low-modulus polyethylene containing wt% was irradiated with ultraviolet rays in a weather μ meter.

Table: Conventional low-molecular-weight benzophenone exhibits a decrease in elongation within 2000 hours, whereas 2,4-dihydroxybenzophenone d conductor, which is made to have a high molecular weight by ultraviolet light, has a
The decrease in elongation up to 0.000 makimono was small, indicating that this compound has a strong ability to prevent photodeterioration.

The difference in the photodegradation prevention function of 11191F is the ultraviolet #I of both.
Since the Alt yield is not large, it is understood that this is due to the slow residual properties of both of them in polyethylene.

As explained above, the photodegradation inhibitor of the present invention has ultraviolet-
It has the advantage of being able to prevent photodeterioration of plastics for a long period of time because it increases its molecular weight by irradiation and improves its retention in plastics.

Claims (1)

[Claims] The structure of the F1 formula is as follows. 2,4-dihydroxybenzophenone substituted with a β-carboxyvinyl group (l in A (□, R1 is H and the other is β-carboxy/vinyl group, or both are I- Carpoxyvinyl group) is a photodegradation inhibitor for plastics.