What is rosin

When it comes to what rosin is, I believe many people find it very unfamiliar. In fact, rosin is a natural resin made from pine resin through a certain processing method. In addition, rosin is also an important chemical raw material, widely used in various industries, including soap, paint and so on. So what are the effects and functions of rosin?

Rosin is a transparent solid substance that is generally insoluble in water. It is one of the important chemical raw materials for making soap, paper and other industrial industries. It can also be used to make fixatives, etc. Below I will give you a detailed answer to the question of what rosin is.

What is rosin?

Rosin is a non-volatile natural resin obtained from pine resin through different processing methods. Rosin is an important chemical raw material and is widely used in soap, papermaking, paint, rubber and other industries.

Interpretation

Basic explanation: A transparent solid substance made from the volatile turpentine oil evaporated from the oleoresin of pine trees. It is hard and brittle, yellow or brown, and is used as an industrial raw material.

Detailed explanation: 1. The unique fragrance in the pine forest. 2. Another name for rosin. 3. Refers to the substance obtained by distilling rosin. Solid, transparent, insoluble in water, hard and brittle, light yellow or brown. It is an industrial raw material for making paint, soap, paper, matches, etc. 4. Amorphous.

definition

1. The unique fragrance of the pine forest. 2.Also known as pine paste, pine fat, and pine glue. 3. Refers to the substance obtained by distilling rosin. Solid, transparent, insoluble in water, soluble in alcohol, hard and brittle, light yellow or brown. It is an industrial raw material for making paint, soap, paper, matches, etc. 4. Rosin is the oil that flows out from the inside of the pine trunk and melts into water at high temperature. After drying, it becomes a block solid (without a fixed melting point). Its color is dark yellow and deep red. It is an important chemical raw material. In daily life, it is mainly used as a flux when welding circuit boards. In terms of musical instruments, rosin is applied to the bow hair of string instruments such as the erhu, violin, and horse-head fiddle to increase the friction of the bow hair on the strings.

Basic performance

Rosin can be divided into three types according to its source: gum rosin, wood rosin and tall oil rosin. Gum rosin is also called loose rosin, which has a light color, high acid value and high softening point; wood rosin is also called extracted rosin, which is not as good as gum rosin, has a dark color, low acid value, and is easy to crystallize from certain solvents; floating oil rosin is also called tall oil rosin. Rosin is a kind of transparent, brittle solid natural resin. It is a relatively complex mixture composed of resin acids (abietic acid, pimaric acid), a small amount of fatty acids, rosin anhydride and neutral substances. It is soluble in ethanol, ether, acetone, toluene, carbon disulfide, ethylene dichloride, turpentine, petroleum ether, gasoline, oils and alkaline solutions. The solubility in gasoline is reduced. Insoluble in cold water, slightly soluble in hot water. Rosin has excellent properties such as viscosity increasing, emulsification, softening, moisture resistance, corrosion resistance, and insulation. Its disadvantage is that it has a strong tendency to crystallize in solvents. The crystallinity of rosin is due to the different solubility of isomers in rosin in certain solvents and the different water content in rosin. Rosin crystallization is one of the important issues affecting rosin quality. It will cause flocs or small precipitated particles to appear in the adhesive and also make the adhesive liquid opaque. The quality of rosin is determined by color, acid value, softening point, transparency, etc. Generally, the lighter the color, the better the quality; the more rosin acid content, the greater the acid value, and the higher the softening point. Rosin has excellent viscosity, especially pressure sensitivity, quick viscosity, and low temperature viscosity, but its cohesive force is poor.

application

Rosin is often used as a tackifying resin in hot melt, pressure sensitive and solvent-based adhesives to increase initial tack and improve bonding strength. Rosin can also improve the drying properties and peel strength of water-based acrylic laminating adhesive, and the optimal dosage is 6% of the total monomer amount. Rosin is a weakly acidic substance. If it is used in excessive amounts in SBS-type all-purpose glue or spray glue, it will cause corrosion to the iron packaging, causing the glue to quickly turn brown-black. Although it does not affect the bonding performance, the appearance is questionable. Rosin is very sensitive to light, heat, and oxygen, especially in powder form, which is very easy to oxidize. Therefore, it should be stored in a whole block to prevent oxidation from darkening the color and changing the properties. When the surface of block rosin is oxidized, an oxide film is formed, which can prevent the internal rosin from further oxidation. Moisture can accelerate the oxidation process of rosin, and acetic acid is released during deep oxidation.

Source Processing

Gum rosin: The rosin obtained by collecting rosin through harvesting and then processing and refining is called gum rosin. Its characteristic is that pine trees can be harvested continuously, which is conducive to the full utilization of resources. Wood rosin: pine roots or trunks are chopped up, the resin is extracted with solvents, and then processed and refined. Mainly produced in the United States, the raw materials rely on the original pine forests in the southeast of the country. Now due to the reduction of forest resources, there is a shortage of wood rosin raw materials. Tall rosin: It comes from the wood pulping and papermaking industry. It is processed from the black liquor returned from kraft pulping. Originally, its performance was inferior to that of gum rosin. Later, due to the continuous improvement of quality, its performance is now similar to that of gum rosin. As the proportion of pine wood used in papermaking decreased, the rosin yield obtained from the fractionation of floating oil was reduced (from 27% to 21%).

Industrial Application

Rosin is a very important chemical raw material and is widely used in various industrial sectors. Its main uses are as follows: Soap industry: Rosin is cooked with pure alkali or alkali to form rosin soap. Rosin soap has great detergency, is easily soluble in water, can dissolve grease, and is easy to foam. Rosin has a sticky property that prevents the soap from cracking and becoming rancid. Papermaking industry: Rosin is used as papermaking sizing agent in the papermaking industry. Rosin and caustic soda are made into rosin sodium soap, that is, sizing. The sizing is mixed with pulp and alum is added to make the rosin into water-insoluble free resin acid particles that attach to small fibers. When the pulp is rolled and heated on a drying cylinder, the rosin softens and fills between the fibers. This effect is called "sizing" or "applying sizing". After the paper is "glued", it can enhance water resistance, prevent ink penetration, improve strength and smoothness, and reduce stretching. Paint and coating industry: Rosin is easily soluble in various organic solvents, easy to form a film, and has gloss. It is one of the basic raw materials for paint and coating. The role of rosin in paint is to make the paint bright in color, dry quickly, and make the paint film smooth and not easy to fall off. Ink industry: Rosin is mainly used as a color carrier in printing ink and enhances the adhesion of ink to paper. If rosin is not used in the ink, the printed ink will be dull and unclear. Adhesive industry: Adhesives based on rosin esters and hydrogenated rosin esters are often used as hot melt adhesives, pressure sensitive adhesives and rubber tackifiers. Rubber Industry: Rosin is used as a softener in the rubber industry to increase its elasticity. Disproportionate rosin potassium soap can be used in the synthetic food industry: hydrogenated rosin glycerol ester is heated and melted with natural sugar gum, wax, vinyl acetate, etc., and then spices, sugar and pigments are added to mix well to make chewing gum. When slaughtering pigs, cattle and sheep in a slaughterhouse, the hair left on the animal's body and head after the depilatory machine can be removed with a depilatory composed of 88-94% molten rosin and 6-12% cottonseed oil.

Electrical industry: 35% rosin and 65% bright oil are mixed into insulating oil and used as a protective film on cables to provide insulation and heat resistance. Rosin is mixed with Bakelite and other artificial resins and used as insulating varnish. Building materials industry: Rosin is mainly used as a concrete foaming agent and floor tile adhesive in the building materials industry. Rosin is also used as an adhesive for vinyl chloride asbestos tiles. Rosin is mixed with linseed oil, calcium carbonate, charcoal, pigments, etc. to make carpet tiles. Making fixative: Due to the solubility and volatility of rosin, and the principle that it can quickly condense into a "solid and transparent film" after volatilization, painters usually make their own "fixative" liquid to protect the painting and prevent the "sketch" from being rubbed off. That is: one part rosin powder, nine parts alcohol, or xylene solvent. First put the rosin in a well-sealed glass container, then pour in the alcohol or xylene, cover the lid, and it will dissolve by itself after two days. When using, shake well and pour into a spray bottle, hold it 20 cm away from the picture, and spray it evenly on the picture. You can spray it at any time and it will evaporate at any time. It will be dry after a few minutes, and you don’t have to worry about it being rubbed off in the future.

After reading the detailed answer to the question of what rosin is above, I believe that you all have a general understanding of this chemical substance called rosin. The application of rosin is very wide. Generally speaking, this material is used in many industries, such as the building materials industry, ink industry, papermaking industry, etc. It can be seen that rosin is a substance that is very useful for our industrial industry.