Chinese name: 1.2 pentadiol

CAS login number: 5343-92-0

Product Specifications:

Appearance: Colorless transparent liquid, soluble in alcohol, ether and ethyl acetate and other organic solvents

Chemical formula: C5H12O2

Molecular weight: 104.15

InChI: InChI=1/C5H12O2/c1-2-3-5(7)4-6/h5-7H,2-4H2,1H3/t5-/m1/s1

InChIKey: WCVRQHFDJLLWFE-UHFFFAOYSA-N

Density: 0.971 g/mL at 25 °C (lit.)

Melting point: 50.86°C (estimate)

Boiling point: 206 °C (lit.)

Flash point: 104 °C

Water soluble: miscible

Steam pressure: 1.5Pa at 20℃

Refractive index: n20/D 1.439(lit.)

Acidity coefficient: 14.49±0.20(Predicted)

Storage conditions: Keep in dark place,Sealed in dry, and Room Temperature

Appearance: Liquid

Color: Clear colorless to light yellow

BRN: 1732199

Physical and chemical properties: 1, 2-pentanediol is a colorless transparent liquid, b.p.206℃, n20D 1.4400, relative density 0.971, soluble in alcohol, ether, ethyl acetate and other organic solvents.

Risk term: 36/38 - eye and skin irritation.

Safety term: 24/25 - Avoid contact with skin and eyes.

WGK Germany: 1

RTECS: SA0455000

Source: Petroleum and natural

1, 2-pentanediol is a naturally-derived humectant with antiseptic properties. Another source of 1, 2-pentanediol is petroleum, which needs to be treated and also has anti-corrosion and moisturizing properties.

Introduction to 1, 2-pentanediol

1, 2-pentanediol is a diol (* 1) with refreshing feeling and excellent antibacterial properties, and also alkanediol, a polyol with high antibacterial properties.

* 1 polyols have extremely high hygroscopic and water-retaining properties, so they are the most commonly used moisturizers in cosmetics. The name "alcohol" is misleading, but ordinary alcohol (ethanol) is a mono alcohol, and polyols and mono alcohols (ethanol) are different substances.

1, 2-pentanediol action

1, 2-pentanediol is an excellent humectant with antibacterial effects, and has a synergistic effect with traditional preservatives and helps to reduce the amount of traditional preservatives in the formula. In sunscreen products, it is more helpful to improve the water resistance of the product and the dissolution ability of some ingredients. 1, 2-pentanediol contributes to the stability of the formula and also reduces the stickiness caused by the addition of polymers to the formula.

1, 2-pentanediol is an important intermediate of propiconazole.

Excellent performance of moisturizing agent, while having anti-corrosion effect, can be prepared preservative-free products, reduce the allergy caused by preservatives;

Can improve the water resistance of sunscreen product formulation;

Dissolve insoluble active ingredients. Used in skin care cream, eye cream, skin care lotion, baby care products, sunscreen products and other skin care products.

The role of 1, 2-pentanediol in skin care products

1, 2-pentadiol has broad-spectrum antibacterial activity, and can also play a role in moisturizing and conditioning skin. It is often added to skin care products, suitable for sensitive skin, infants and other delicate skin, as well as aging and dry skin care, and can also be used for hair care. 1, 2-pentanediol products for personal care products have high purity, colorless, odorless, and no irritating impurities.

1, antibacterial: 1, 2-pentanediol has a good inhibitory effect on Gram positive bacteria, negative bacteria, mold, can be added to the bactericide propionazole, made into cream can be applied on the skin, can play a certain antibacterial effect, conducive to inhibiting the growth of pathogenic bacteria;

2, moisturizing and moisturizing: 1, 2-pentanediol is a relatively good moisturizing agent, added to cosmetics can achieve the moisturizing effect, can play a role in nourishing the skin, but also can quickly supplement the moisture needed by the skin, improve the dry state of the skin, relieve skin peeling, dandruff situation, but also can improve the water resistance of sunscreen products;

3, skin conditioning: 1, 2-pentanediol can be added in skin care products, such as water, cream, essence, etc., and can also be added in eye cream. Using these skin care products can nourish the skin, make the skin more tender and elastic, and also play the effect of skin conditioning, improve the dry skin and enlarged pores, but it needs to be applied continuously to achieve the effect.

About skin irritation

Review safety test data against safety components

·[Human trial] When 0.2g of a semi-closed patch containing 0.112% pentadiol was applied to the back of 101 subjects for 24 hours, it was concluded that there was no skin irritation.

[Human trials] extracted seven highly sensitive skin irritants from 70 healthy subjects and applied products containing glutarglycol and parabens to the cheeks of these seven subjects. However, when skin irritation was assessed with its own skin irritation score (determined to be 1.0 strong irritation), products containing parabens were 1.3, while products containing pentanol were 0.4. Judged no skin irritation.

Based on test data, almost no skin irritation is usually reported because no skin irritation is usually reported.

About eye irritation

Review safety test data against safety components

·[Animal tests] When a gel containing 3.0% pentanediol was applied to the eyes of domestic rabbits, there was slight eye irritation.

Based on test data, minor eye irritation has been reported, so minor eye irritation may occur.

About Skin allergies

Review safety test data against safety components

·[Human trial] After applying 0.2 grams of foundation semi-closed patch with 101 grams of pentadiol to 101 back subjects for 24 hours, it was concluded that there was no skin allergy.

- Individual cases -

Review safety test data against safety components

A 68-year-old non-atopic woman developed dermatitis on her face after using an eye cream containing pentadiol, so the patch test was positive for both 0.5% and 5% pentadiol. But in 29 subjects, reactions to 0.5% and 5% pentanediol were negative

According to test data, skin is generally considered to be almost non-allergenic, and there are few reports of skin allergies.

1, 2-pentanediol is divided into basic components, moisturizing components and preservative components.

preparation

The molar ratio of 1-pentene, hydrogen peroxide and formic acid is 1∶1.5∶4. The reaction equilibrium mixture is formed by the following procedure: 1-pentene and hydrogen peroxide (70%) are slowly added to formic acid at the same time at 40 ~ 55℃. After addition, the mixture is stirred at 55℃ for 1 hour and transferred to a circulating reactor with a circulating pump and overflow siphon, heated to 55℃ and circulated, and then 1-pentene and formic acid are added by an adding tube. Hydrogen peroxide is added from the other addition tube, and exothermic reaction occurs at this time, and the temperature is allowed to rise to 62 ~ 63℃. These components are added according to a certain proportion and speed, and the balanced operation is controlled by a cyclic constant temperature device. After about 8h, the reaction stops, and a large amount of 1, 2-pentanediol formates are obtained. The residue was hydrolyzed with 25%NaOH solution and then extracted by solvent extraction and dissolvation distillation to obtain 1, 2-pentanediol with a yield of 91% at MP.96-98 ℃/1.3kPa.

cost

1, 2-pentanediol is the key raw material for the synthesis of the bactericide propiconazole, and the global consumption is more than 2000 tons/year. At present, the quotation of 1, 2-pentanediol imported from China is about 100,000 yuan/ton.

The synthesis processes reported in the existing literature mainly include the following methods:

N-valerate method: n-valerate bromide -- > 2-bromo-n-valerate -- > 2-hydroxy-n-valerate -- >1, 2-pentanediol. The production cost is over 100,000 yuan/ton

Amyl alcohol method: just 1 - pentene - amyl alcohol dehydration - > > epoxy pentane - > 1, 2-1 - butyl glycol production costs more than 60000 yuan/ton [2]

improvement

Using formic acid solution of 1, 2-epoxy-pentane and calcium hydroxide as starting materials, 1, 2-pentoglycol and calcium formate with high purity and high yield were obtained through neutralization, hydrolysis, filtration drying, concentration, extraction, filtration drying, concentration and rectification. The total yield of 1, 2-pentanediol was 92.8% and the content was 99.5%. The yield of calcium formate was 95% and the content was ≥98%. This method has mild reaction conditions, simple operation and is suitable for industrial production. [2]

Upstream and downstream products

Upstream raw materials: formate, 1-pentene

Downstream product: Propiconazole