View source for Rosin

{{short description|Solid form of resin}}
{{other uses|Rosin (disambiguation)}}
[[File:Maison du patrimoine de Mimizan colophane 2.jpg|thumb|A piece of rosin at Mimizan Heritage House, France]]

'''Rosin''' ({{IPAc-en|'|r|ɒ|z|ɪ|n}}), also known as '''colophony''' or '''Greek pitch''' ({{langx|la|links=no|pix graeca}}), is a [[resin]]ous material obtained from [[pine]] trees and other [[plant]]s, mostly [[Pinophyta|conifers]].  The primary components of rosin are [[Diterpene|diterpenoids]], i.e., C<sub>20</sub> [[carboxylic acid]]s. Rosin consists mainly of [[resin acids]], especially [[abietic acid]].<ref name=Ullmann>{{cite book |doi=10.1002/14356007.a23_073 |chapter=Resins, Natural |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2000 |last1=Fiebach |first1=Klemens |last2=Grimm |first2=Dieter |isbn=978-3-527-30673-2}}</ref> Rosin often appears as a semi-transparent, brittle substance that ranges in color from yellow to black and melts at stove-top temperatures. 

In addition to industrial applications such as in varnishes, adhesives, and sealing wax, rosin is used with [[string instrument]]s on the [[Bow (music)|bow hair]] to enhance its ability to grip and sound the strings, and it provides grip in various sports and activities. Rosin also serves as an ingredient in medicinal and pharmaceutical formulations and can cause [[contact dermatitis]] or [[occupational asthma]] in sensitive individuals. It is an [[FDA]] approved food additive.<ref>{{Cite journal |last=Nutrition |first=Center for Food Safety and Applied |date=2022-08-25 |title=Food Additive Status List |url=https://www.hfpappexternal.fda.gov/scripts/fdcc/index.cfm?set=FoodSubstances |journal=FDA |language=en}}</ref>

The name "colophony" originates from {{lang|la|colophonia resina}}, Latin for "resin from [[Colophon (city)|Colophon]]" ({{langx|grc|Κολοφωνία ῥητίνη|Kolophōnía rhētínē}}),<ref>{{L&S|Colophon1|Colophon|ref}}</ref><ref>{{LSJ|*kolofw/nios|Κολοφώνιος|ref}}.</ref> an ancient [[Ionia|Ionic]] city.<ref>{{OED|colophony}} "{{abbr|ad.|adaptation of}} {{abbr|L.|Latin}} {{lang|la|colophōnia}} ([[Pliny the Elder|Pliny]]) for {{lang|la|Colophōnia rēsīna}} resin of [[Colophon (city)|Colophon]]".</ref>

==Properties==
[[Image:Kolophonium.jpg|thumb|Pharmaceutical rosin]]

Rosin is [[brittle]] and [[friable]], with a faint pine odor. It is typically a [[glass]]y solid, though some rosins will [[crystal]]lize, especially when brought into solution.<ref>{{cite journal |doi=10.1007/BF02639482 |title=A new non-crystallizing gum rosin |year=1938 |last1=Palkin |first1=S. |last2=Smith |first2=W. C. |journal=Oil & Soap |volume=15 |issue=5 |pages=120–122|s2cid=94421680 }}</ref> The practical melting point is variable, some being semi-fluid at the temperature of boiling water, others melting at {{convert|100|to|120|C|F}}. It is flammable, burning with a smoky flame. It is soluble in [[ethanol|alcohol]], [[diethyl ether|ether]], [[benzene]] and [[chloroform]].

Rosin, consisting mainly of [[abietic acid]], combines with caustic [[alkali]]s to form salts (rosinates or pinates) that are known as rosin soaps. They are used in [[soap making]].

==Uses==
[[Image:Abietic acid.svg|thumb|Structure of [[abietic acid]], a component of rosin]]
* It is rubbed on the hair of [[bow (music)|bows]] for [[bowed string instrument]]s to increase friction.

* It has been used for centuries for [[caulking]] [[ships]].<ref name=EB>{{cite encyclopedia |editor-first=Dale H. |editor-last=Hoiberg |encyclopedia=Encyclopædia Britannica |title=abietic acid |edition=15th |year=2010 |publisher=Encyclopædia Britannica Inc. |volume=I: A-ak Bayes |location=Chicago, Illinois |isbn=978-1-59339-837-8 |pages=[https://archive.org/details/newencyclopaedia2009ency/page/32 32] |url-access=registration |url=https://archive.org/details/newencyclopaedia2009ency/page/32 }}</ref> 

* It is approved by the US [[Food and Drug Administration|FDA]] as a miscellaneous food additive.<ref name=":0">{{Cite journal |last=Nutrition |first=Center for Food Safety and Applied |date=2022-08-25 |title=Food Additive Status List |url=https://www.hfpappexternal.fda.gov/scripts/fdcc/index.cfm?set=FoodSubstances |journal=FDA |language=en}}</ref> 

* It is an ingredient in [[printing]] [[ink]]s, photocopying and laser printing paper, [[varnish]]es, [[adhesive]]s (glues), [[soap]], [[sizing|paper sizing]], [[Soft drink|soda]], [[solder]]ing [[Flux (metallurgy)|fluxes]], and [[sealing wax]]. 

* It can be used as a [[glazing agent]] in [[medicine]]s and [[chewing gum]]. It is denoted by [[E number]] E915. A related [[Glycerol esters of wood rosins|glycerol ester (E445)]] can be used as an [[emulsifier]] in [[soft drink]]s. In [[pharmaceutical]]s, rosin forms an ingredient in several plasters and ointments.

* In industry, rosin is a [[flux (metallurgy)|flux]] used in [[soldering]]. The [[lead]]-[[tin]] [[solder]] commonly used in electronics has 1 to 2% rosin by weight as a flux core, helping the [[melting|molten]] [[metal]] flow and making a better connection by [[redox|reducing]] the refractory solid [[oxide]] layer formed at the surface back to metal. It is frequently seen as a burnt or clear residue around new soldering.

* Rosin is also sometimes used as internal reinforcement for very thin skinned metal objects - like silver, copper or tin plate candlesticks, or sculptures, where it is simply melted, poured into a hollow thin-skinned object, and left to harden.

* A mixture of [[pitch (resin)|pitch]] and rosin is used to make a surface against which [[glass]] is [[polishing|polish]]ed when making optical components such as [[lens]]es.

* Rosin is added in small quantities to traditional [[linseed oil]]/sand gap fillers ("mastic"), used in building work.

* When mixed with waxes and oils, rosin is the main ingredient of ''mystic smoke'', a gum which, when rubbed and suddenly stretched, appears to produce puffs of [[smoke]] from the fingertips.

Rosin is extensively used for its [[friction]]-increasing capacity in several fields:
*  [[Ballet]], [[flamenco]], and [[Irish dance]]rs are known to rub the tips and heels of their shoes in powdered rosin to reduce slippage on clean wooden dance floors or competition/performance stages. It was at one time used in the same way in [[fencing]] and is still used as such by [[boxing|boxers]].
* [[Team handball]] players use it to improve grip. [[Rock climbers]] have used it in some locations.
* [[Olympic weightlifting|Olympic weightlifters]] rub the soles of their weightlifting boots in rosin to improve [[Traction (engineering)|traction]] on the platform.
* It is applied to the [[race track|track]] surface at the starting line of [[drag racing]] courses to improve traction.{{citation needed|date=March 2022}}
* [[Bull riding|Bull riders]] rub rosin on their rope and glove for additional grip.
* [[Baseball pitcher]]s and [[Ten-pin bowling|ten-pin bowlers]] may use a small cloth bag of powdered rosin for better ball control. Baseball players sometimes combine rosin with sunscreen, creating a very sticky substance that allows far more grip on the ball than the rosin alone will; the use of such a substance is a violation of [[Major League Baseball]] rules.
* Rosin can be applied to the hands in aerial [[acrobatics]] such as [[aerial silks]] and [[pole dancing]] to increase grip.

[[File:Plaque et resine.JPG|thumb|An [[etching]] plate covered with powder resin]]

Other uses that are not based on friction:
* [[Fine art]] uses rosin for [[tempera]] [[emulsion]]s and as painting-medium component for [[oil painting]]s. It is soluble in oil of [[turpentine]] and turpentine substitute, and needs to be warmed.
* In a [[printmaking]] technique, [[aquatint]] rosin is used on the [[etching]] plate in order to create surfaces in gray tones.
* In [[archery]], when a new [[bowstring]] is being made or waxed for maintenance purposes, rosin may be present in the wax mixture. This provides an amount of tackiness to the string to hold its constituent strands together and reduce wear and fraying.{{citation needed|date=June 2015}}
* [[dog grooming|Dog groomers]] use powdered rosin to aid in removal of excess hair from deep in the ear canal by giving the groomer a better grip to grasp the hairs with. 
* Some brands of [[fly paper]] use a solution of rosin and rubber as the adhesive.
* Rosin is sometimes used as an ingredient in dubbing wax used in [[fly tying]].
* Rosin is used hot to de-encapsulate [[epoxy]] [[integrated circuit]]s.<ref>{{cite web |url=https://www.youtube.com/watch?v=pIpxawdUb4I  |archive-url=https://ghostarchive.org/varchive/youtube/20211221/pIpxawdUb4I |archive-date=2021-12-21 |url-status=live|title=Peter Laackmann, Marcus Janke: Uncaging Microchips (from 30:18-32:15)|author=Peter Laackmann, Marcus Janke |website=[[YouTube]]|date=Dec 28, 2014 |access-date=Feb 18, 2016}}{{cbignore}}</ref>
* Rosin can be mixed with beeswax and a small amount of linseed oil to affix reeds to reed blocks in accordions.

Rosin and its derivatives also exhibit wide-ranging pharmaceutical applications. Rosin derivatives show excellent film forming and coating properties.<ref>{{cite journal |first1=Prashant M. |last1=Satturwar |first2=Suniket V. |last2=Fulzele |first3=Avinash K. |last3=Dorle |doi=10.1208/pt060481 |title=Evaluation of polymerized rosin for the formulation and development of transdermal drug delivery system: A technical note |year=2005 |journal=AAPS PharmSciTech |volume=6 |issue=4 |pages=E649–E654 |pmid=16408867 |pmc=2750614}}</ref> They are also used for tablet film and enteric coating purpose. Rosins have also been used to formulate microcapsules and nanoparticles.<ref>{{cite journal |pages=1487–90 |doi=10.1007/s10529-005-1316-x |title=Rosin Nanoparticles as a Drug Delivery Carrier for the Controlled Release of Hydrocortisone |year=2005 |last1=Lee |first1=Chang-Moon |last2=Lim |first2=Seung |last3=Kim |first3=Gwang-Yun |last4=Kim |first4=Dong-Woon |last5=Rhee |first5=Joon Haeng |last6=Lee |first6=Ki-Young |journal=Biotechnology Letters |volume=27 |issue=19 |pmid=16231221|s2cid=24729281 }}</ref><ref>{{cite journal |doi=10.1080/02652040410001653768 |title=Preparation and evaluation of microcapsules using polymerized rosin as a novel wall forming material |year=2004 |last1=Fulzele |first1=S. V. |last2=Satturwar |first2=P. M. |last3=Kasliwal |first3=R. H. |last4=Dorle |first4=A. K. |journal=[[Journal of Microencapsulation]] |volume=21 |pages=83–89 |pmid=14718188 |issue=1|s2cid=24929166 }}</ref>

[[Glycerol]], [[sorbitol]], and [[mannitol]] esters of rosin are used as [[chewing gum]] bases for medicinal applications. The degradation and [[biocompatibility]] of rosin and rosin-based biomaterials has been examined [[in vitro]] and [[ex vivo]].

===Rosin soaps and esters===
Treatment of rosin with sodium hydroxide or sodium carbonate converts the abietic acid into its sodium salt, which is known as a soap.  Whereas most domestic soaps are sodium salts of straight-chain fatty acids, the rosin soaps have the branched and cyclic backbone associated with abietic acid.  Rosin soaps, also called rosinates, are used to "size" paper, a process that gives paper a desirable hydrophobic texture.<ref name=Ullmann/>

The conversion of abietic acid to esters is also practiced commercially.  Ester of glycerol and methanol are both of interest.  These materials are colorless syrups.  They are compounded with polymers as [[tackifier]]s.<ref name=Ullmann/>

===Violin rosin===
[[File:Rosin.jpg|thumb|A cake of rosin, made for use by violinists to rub on the violin bow.]]
[[Image:Rosins.JPG|thumb|left|Various types of rosin for violins, violas and cellos]]

Players of [[Bow (music)|bowed string instruments]] rub cakes or blocks of rosin on their bow hair so it can grip the strings and make them "speak", or vibrate clearly.<ref>{{cite book |title=Cello Technique: Principles and Forms of Movement |first=Gerhard |last=Mantel |chapter=Problems of Sound Production: How to Make a String Speak |chapter-url=https://books.google.com/books?id=LD9teSPY2Z0C&pg=PA135 |pages=[https://archive.org/details/cellotechniquepr00mant/page/135 135–41] |isbn=978-0-253-21005-0 |year=1995 |publisher=Indiana University Press |url-access=registration |url=https://archive.org/details/cellotechniquepr00mant/page/135 }}</ref> Occasionally, substances such as [[beeswax]], [[gold]], [[silver]], [[tin]], or [[meteoric iron]]<ref>{{cite web |url=http://www.larica.ch/en/ |title=Larica metal rosin |author=<!--Staff writer(s); no by-line.--> |date=2009 |access-date=Jun 15, 2014 |archive-date=June 27, 2015 |archive-url=https://web.archive.org/web/20150627180706/http://www.larica.ch/en/ |url-status=live }}</ref> are added to the rosin to modify its [[stiction]]/[[friction]] properties and the tone that can be produced.<ref>{{cite web|url=http://www.stringsmagazine.com/issues/strings115/yourinstrument.html|title=All Things Strings:Rosin|date=1 May 2010|url-status=bot: unknown|archive-url=https://web.archive.org/web/20100501151147/http://www.stringsmagazine.com/issues/strings115/yourinstrument.html|archive-date=1 May 2010}}</ref> Powdered rosin can be applied to new hair, for example with a felt pad or cloth, to reduce the time taken in getting sufficient rosin onto the hair. Rosin is often reapplied immediately before playing the instrument. Lighter rosin is generally preferred for violins and violas, and in high-humidity climates, while darker rosins are preferred for cellos, and for players in cool, dry areas.<ref>{{cite web |url=http://stringsmagazine.com/the-differences-between-dark-and-amber-rosin/ |title=The Differences Between Dark and Amber Rosin |author=Heather K. Scott |date=January 5, 2004 |access-date=Dec 27, 2016 |archive-date=November 26, 2016 |archive-url=https://web.archive.org/web/20161126012003/http://stringsmagazine.com/the-differences-between-dark-and-amber-rosin/ |url-status=live }}</ref> There are also specific, distinguishing types for [[Bass (instrument)|basses]].
* Violin rosin can be applied to the [[Bridge (instrument)|bridges]] in other musical instruments, such as the [[banjo]] and [[banjolele]], in order to prevent the bridge from moving during vigorous playing.

The type of rosin used with bowed string instruments is determined by the diameter of the strings. Generally this means that the larger the instrument is, the softer the rosin should be. For instance, [[double bass]] rosin is generally soft enough to be [[wikt:pliable|pliable]] with slow movements. A cake of bass rosin left in a single position for several months will show evidence of flow, especially in warmer weather.

== Production ==
Three methods are used to collect rosin.  Rosin exudates are collected from gashes in the bark of living pine trees.  Alternatively (see below) rosin is [[solvent extraction|extracted]] from stumps.  Yet another source is pulp mills that use the [[Kraft process]]. [[Tall oil]] rosin is produced during the distillation of crude tall oil, a by-product of the [[kraft paper]] making process. The collection and processing of rosin is called [[Naval Stores]].

The separation of the oleo-resin into the [[essential oil]] (spirit of turpentine) and common rosin is accomplished by [[distillation]] in large copper [[still]]s. The essential oil is carried off at a temperature of between {{convert|100|C|F}}° and {{convert|160|C|F}}, leaving fluid rosin, which is run off through a tap at the bottom of the still, and purified by passing through straining wadding. Rosin varies in color, according to the age of the tree from which the turpentine is drawn and the degree of heat applied in distillation, from an [[Opacity (optics)|opaque]], almost pitch-black substance through grades of brown and yellow to an almost perfectly transparent colorless glassy mass. The commercial grades are numerous, ranging by letters from A (the darkest) to N (extra pale), superior to which are W (window glass) and WW (water-white) varieties, the latter having about three times the value of the common qualities.

When pine trees are harvested "the resinous portions of fallen or felled trees like longleaf and slash pines, when allowed to remain upon the ground, resist decay indefinitely."<ref name=USFS>{{cite web | title = Distillation of Resinous Wood|id = 496 | author = Beglinger, E. | date = May 1958 | publisher = United States Department of Agriculture Forest Service | url-status = live| url = https://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/910/FPL_496ocr_rev.pdf?sequence=1 | archive-date = 2014-01-07 | archive-url = https://web.archive.org/web/20140107071114/https://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/910/FPL_496ocr_rev.pdf?sequence=1  }}</ref> This "stump waste", through the use of [[destructive distillation]] or solvent processes, can be used to obtain rosin. This type of rosin is typically called '''wood rosin'''.

[[Image:Rosin.JPG|thumb|Colophony (rosin) from the [[maritime pine]]]]

Because the turpentine and pine oil from destructive distillation "become somewhat contaminated with other distillation products",<ref name=USFS/> solvent processes are commonly used. In this process, stumps and roots are chipped and soaked in the light end of the heavy [[naphtha]] fraction (boiling between {{convert|90|and|115|C|F}}). Multi-stage counter-current [[solid phase extraction|extraction]] is commonly used. In this process, fresh naphtha first contacts wood leached in intermediate stages, and naphtha laden with rosin from intermediate stages contacts unleached wood before [[vacuum distillation]] to recover naphtha from the rosin, along with [[fatty acid]]s, turpentine, and other constituents separated through [[steam distillation]] or dry distillation<ref name="Tall Oil Distillation">{{cite web|title=Tall Oil Distillation|author=H. Kooijman|date=October 2025|url-status=live|access-date=2025-10-26|url=http://chemsep.org/downloads/data/Tall_Oil_Distillation.pdf|website=chemsep.org
}}</ref>. Leached wood is steamed for additional naphtha recovery prior to burning for energy recovery.<ref>Kent pp.571&572</ref> After the solvent has been recovered, "the terpene oils are separated by [[fractional distillation]] and recovered mainly as refined turpentine, dipentene, and pine oil. The nonvolatile residue from the extract is wood rosin of rather dark color. Upgrading of the rosin is carried out by clarification methods that generally may include bed-filtering or [[furfural]]-treatment of rosin-solvent solution."<ref name=USFS/>

On a large scale, rosin is treated by destructive distillation for the production of rosin spirit, pinoline and rosin oil. The last enters into the composition of some of the solid lubricating [[Grease (lubricant)|grease]]s, and is also used as an [[adulterant]] of other oils.

===Locales===
The chief region of [[Resin extraction|rosin production]] includes [[Indonesia]], southern [[China]] (such as [[Guangdong]], [[Guangxi]], [[Fujian]], [[Yunnan]] and [[Jiangxi]]), and the northern part of [[Vietnam]]. Chinese rosin is obtained mainly from the [[turpentine]] of [[Masson's pine]] ''Pinus massoniana'' and [[slash pine]] ''P. elliottii''.{{Citation needed| date=October 2008}} The latter species is native to the southeastern U.S., but is now widely planted in tree plantations in China.

The [[South Atlantic States|South Atlantic]] and eastern [[Gulf Coast of the United States|Gulf states]] of the [[United States]] is a second chief region of production. American rosin is obtained from the turpentine of [[longleaf pine]] ''Pinus palustris'' and [[loblolly pine]] ''P. taeda''. In [[Mexico]], most of the rosin is derived from live tapping of several species of [[pine]] trees, but mostly ''[[Pinus oocarpa]]'', ''[[Pinus leiophylla]]'', ''[[Pinus devoniana]]'' and ''[[Pinus montezumae]]''. Most production is concentrated in the west-central state of [[Michoacán]].{{Citation needed|date=October 2008}}

The main source of supply in [[Europe]] is the [[France|French]] district of [[Landes forest|Landes]], in the [[Departments of France|departments]] of [[Gironde]] and [[Landes (department)|Landes]], where the [[maritime pine]] ''P. pinaster'' is extensively cultivated. In the north of Europe, rosin is obtained from the [[Scots pine]] ''P. sylvestris'', and throughout European countries local supplies are obtained from other species of pine, with [[Aleppo pine]] ''P. halepensis'' being particularly important in the [[Mediterranean]] region.{{Citation needed|date=October 2008}}

== Health effects ==
Prolonged exposure to rosin fumes released during soldering can cause [[occupational asthma]] (formerly called ''colophony disease''<ref>{{Cite web |url=http://www.antiquusmorbus.com/English/Occupational.htm |title="colophony disease", ''Archaic Medical Terms List, Occupational'', on ''Antiquus Morbus'' website |access-date=2007-03-13 |archive-date=2011-09-03 |archive-url=https://web.archive.org/web/20110903212444/http://www.antiquusmorbus.com/English/Occupational.htm }}</ref> in this context) in sensitive individuals, although it is not known which component of the fumes causes the problem.<ref>{{Cite web |date=August 2015 |title=Controlling health risks from rosin (colophony)-based solder flux fume |url=http://www.hse.gov.uk/pubns/indg249.pdf |website=hse.gov.uk}}</ref> The symptoms also include [[desquamation]] of [[Bronchus|bronchial]] [[epithelium]].<ref>{{Cite journal|last1=Meehan-Atrash|first1=Jiries|last2=Strongin|first2=Robert M.|date=2020-07-01|title=Pine rosin identified as a toxic cannabis extract adulterant|journal=Forensic Science International|language=en|volume=312|article-number=110301|doi=10.1016/j.forsciint.2020.110301|issn=0379-0738|pmc=7426011|pmid=32460222}}</ref>

Prolonged exposure to rosin, by handling rosin-coated products, such as [[laser printer]] or photocopying paper, can give rise to a form of industrial [[contact dermatitis]].<ref>{{cite web|url=http://www.dermnet.org.nz/dermatitis/rosin-allergy.html|title=Rosin allergy - DermNet New Zealand|website=www.dermnet.org.nz|access-date=2010-02-13|archive-date=2013-02-09|archive-url=https://web.archive.org/web/20130209124844/http://dermnet.org.nz/dermatitis/rosin-allergy.html}}</ref>

==See also==
* [[Copal]]
* [[Amber]]

==Notes==
{{reflist}}

== References ==

{{refbegin}}
* Kent, James A. ''Riegel's Handbook of Industrial Chemistry'' (Eighth Edition). Van Nostrand Reinhold Company (1983). {{ISBN|0-442-20164-8}}.
{{refend}}

==External links==
* {{cite web |url=http://stringsmagazine.com/sticky-business-how-rosin-is-made/ |title=Sticky Business: How Rosin Is Made |first=Paul |last=Kotapish |date=November–December 2001 |work=Strings}}

{{E number infobox 910-919}}
{{Non-timber forest products}}

[[Category:Resins]]
[[Category:Wood extracts]]