Four formula ingredients and selection guide for sunscreen

Sunscreen is indispensable in summer, whether you go out daily or travel long distances. In fact, it has been more than 70 years since the first sunscreen was introduced, and there are more and more types of sunscreen formulas. Today, I will take you to learn about the four formula ingredients and ingredients of sunscreen. Selection of sunscreen types:

1. The four formula raw materials of sunscreen:

Stearic acid:

Stearic acid, also known as stearic acid, is a fatty acid widely found in nature and is found in almost all oils. There are stearic acids in varying amounts. The content in animal fats is relatively high. For example, the content in butter can reach 24%. The content in vegetable oils is less. Camellia oil is 0.8% and palm oil is 6%. However, in cocoa butter, the content is 0.8%. The content is as high as 34%. There are two main production methods for industrial stearic acid: fractionation method and pressing method. A decomposing agent is added to the hardened oil, and then it is hydrolyzed to obtain crude fatty acids, which are then washed, distilled, and decolorized to obtain the finished product, while glycerol is produced as a by-product.

In the cosmetics industry, it is an indispensable raw material for the manufacture of general emulsified products, and is used to prepare creams, cold creams, foundation creams, shaving creams, hair lotions and skin care lotions, etc. Among them, it plays an emulsifying role in two types of skin care products: snow cream and cold cream, turning it into a stable and white paste.

Stearyl alcohol:

Stearyl alcohol appears as white flake or granular solid, with Fragrance, insoluble in water, soluble in ethanol, ether, benzene and chloroform. It can be obtained by hydrolysis of pilot whale oil, hydrogenation of stearic acid under the catalysis of copper chromate, or reduction of ethyl stearate with saturated ethanol. It can also be obtained by controlling the polymerization reaction of ethylene under the action of alkyl aluminum, and then obtain the heptadecene fraction through oxo synthesis.

Vaseline:

Vaseline is a semi-liquid mixture of alkanes or saturated hydrocarbons. Also called petrolatum, it is produced by fractionation of petroleum. Its state is between solid and liquid at normal temperature. It has three colors: brown, yellow and white due to different uses. Natural petroleum jelly is derived from petroleum residual oil concentrates such as paraffin heavy oil; artificial petroleum jelly is derived from a mixture of mineral oil thickened with pure ozokerite or paraffin wax and paraffin grease. Vaseline has a mineral oil smell, not kerosene smell. It can be used as raw material for pharmaceuticals and cosmetics, as well as for machine lubrication.

Vaseline is an important component of sunscreen. It is often used in waterless sunscreen products, including sunscreens and after-sun insulation products. Vaseline protects the skin from damage and reduces sun-spot cells.

Propylene glycol:

Propylene glycol is an organic compound (diol), usually slightly Sweet, odorless, colorless and transparent oily liquid, hygroscopic and easily mixed with water, acetone, and chloroform. Propylene glycol is produced by the hydration of propylene oxide. It can be used as a wetting agent in combination with glycerin or sorbitol in toothpaste and cosmetics.

2. Should I choose the right sunscreen for different skin types?

Sunscreen can be divided into physical sunscreen and chemical sunscreen. But chemical sunscreens have better skin feel and visual effects, while people with sensitive or extremely dry skin are more suitable for physical sunscreens.

Oily skin should choose foam cleansers with strong cleansing power and water-based sunscreen products with strong penetration; dry skin should choose milk cleansers Products and cream sunscreen products; a wide range of options for normal skin. Lotion and spray sunscreens are basically suitable for all skin types.

Acne-prone skin:

Sunscreen can prevent acne. For acne-prone skin, sunscreen can not only prevent acne and acne marks, but also prevent skin aging. For acne-prone skin, SPF30 sunscreen is a must every day, and you can also add some VC to reduce free radicals in the body.

For acne-prone skin, try to choose products that do not contain acne-causing ingredients. Try to avoid sunscreens containing the following ingredients: butyl stearate, cocoa butter, cinnamon oil, coconut oil, and decyl oleate. Esters, isopropyl isostearate, isopropyl myristate, isopropyl pivalate, isopropyl palmitate, myristyl myristate, myristyl myristate, octyl palmitate, stearin octyl acid ester, peppermint oil, or propylene glycol-2 (PPG-2). Sunscreen can control skin oiliness. Sun exposure can dehydrate your skin and damage its barrier. The skin will produce oil to resist moisture loss. The more oil the face produces, the more likely it is to get acne. For acne-prone skin, it is best to choose a product that combines physical sunscreen and chemical sunscreen. Chemical sunscreen can ensure freshness and non-stickiness, while physical sunscreen can absorb oil.

Dry skin, sensitive skin:

Dry skin should choose sunscreen rich in moisturizing ingredients , such as glycerin, propylene glycol, butylene glycol, hyaluronic acid, etc., products containing jojoba oil can also provide additional protection to the skin.

As for sensitive skin, avoid some irritating ingredients, such as avobenzone, benzophenone, oxybenzone, methoxycinnamic acid and para-aminobenzoic acid (PABA).