WO2013060943A1

WO2013060943A1 - A method for treating wooden material and wooden material produced by the method

Info

Publication number: WO2013060943A1
Application number: PCT/FI2012/051035
Authority: WO
Inventors: Jari-Jukka Kukkonen; Juha Koskela; Toivo Mertaniemi
Original assignee: Bt Wood Oy
Priority date: 2011-10-28
Filing date: 2012-10-26
Publication date: 2013-05-02
Also published as: FI20116062A0; FI20116062L

Abstract

The invention relates to a method for treating wooden material, wherein said wooden material is brought into contact with a composition containing tall oil pitch liquid or emulsion of tail oil pitch so that tall oil pitch penetrates into said wooden material. The invention also relates to a wooden material – tall oil pitch-product, produced by treating wooden material with the method.

Description

A METHOD FOR TREATING WOODEN MATERIAL AND WOODEN MATERIAL PRODUCED BY THE METHOD

Technical field

The invention relates to a method for treating wood by tall oil pitch or aqueous tall oil emulsion according to preamble of claim 1 .

Background

In Europe, raw wood material is expensive, and raising the degree of pro- cessing is widely seen as the only choice in the field to secure the growth or even maintenance of the industry at the present level. The inhibition of biological decay of wood and the improvement of fire resistance and water resistance of wood are known to be areas in which the degree of wood processing should be particularly increased. For example, fire safety is a significant barrier to wood construction. Changes in colour (UV stability) dimensions and cracking or increasing the strength of wood and engineering wood structures are also significant aspects in this respect.

There had been no significant development in relation to the impregnation of wooden material till 1000 AD. From 16th century on some merchant vessels had been preserved against decay fungi and marine borers by treating carbonization and soaking into wood tar. In addition to this, with industrial developments other preservative materials such as oils, glues, resins, rubbers and salts had been used. Impregnation industry has advanced for the last 200 years in parallel with the developments in industrial sector.

The preservative materials used in impregnation industry have evolved as another industry field. They are classified with regard to their effect forms, areas they affect and cost. Today the degrees of toxicity with variety of preservatives limit their production and utilization. The use of chemical preservatives in some areas have been restricted, and even prohibited following the protest of environmentalist organizations in recent years.

The oldest preservatives are based on oils (oil borne preservatives) such as coal and materials derived from coal and petroleum products. Of these, most significantly the creosote is still being used especially for treating wood material that will be in use outdoor and in the sea for long period. Carbolineum, coal-tar, brown coal-tar and wood-tar are among these types. Besides, creosotes enriched by PCP (pentachlorophenol), copper, arsenic, zinc are also used. Railway sleepers that are treated with creo- sote endure 35-40 years. Oil borne preservatives based on creosote or mineral oils are typically toxic and harmful to environment.

Crude tall oil (CTO) is a major chemical by-product of the kraft pulp industry. Investigations have already been made into the possible use of tall oil as a wood protection agent. Paajanen & L. & Ritschkoff , A.C., ( Effect of crude tall oil, linseed oil and rapeseed oil on the growth of the decay fungi. The International Research Group on Wood Preservation. 33rd Annual Meeting in Cardiff, United Kingdom, 12-17 May, 2002), studied the influence of crude tall oil on the growth of fungi and found it to inhibit the growth of three decay fungi in culture media, the brown rot fungi Coni- ophora puteana and Poria placenta and the white rot fungi Coriolus versicolor, and a similar effect was found by Alfredsen et al., (Alfredsen, G., Flaete, P.O., Temiz, A., Eikenes, M. & Militz, H., Screening of the efficacy of tall oils against wood decay fungi. The International Research Group on Wood Preservation. 35th Annual Meeting in Ljubljana, Slovenia, 6-10 June, 2004) who screened the potential of certain commercially available refined tall oils with different chemical compositions as potential wood protection agents. However, the tendency for tall oil to exude from the wood arises from the high amounts used and the lack of oxygen inside the wood, which prevents polymerization and oxidation of the oil, causing the polymerized oil to exude with time to form a pitch-like surface. This also restricts the applications of wood products treated with tall oil.

Crude tall oil (CTO) is a resinous by-product from the manufacture of chemical wood pulp. This by-product is used in the manufacture of such products as soaps, coatings and oils.

Tall oil distillation removes the low viscosity tall oil and resin acids fractions from the crude tall oil and leaves a high viscosity distillation residue called tall oil pitch (TOP). Tall oil pitch (TOP) is a non-distillable residue left from the fractionation of tall oil. The pitch, which is removed from the base of a stripping tower during a flash distillation step, is a semi-fluid, a tar-like material containing most of the higher alcohols and sterols from the original crude tall oil along with rosin and fatty acids. A typical tall oil pitch material may include 12-30% rosin acids and esters, 35-50% fatty acids and esters and 20-35% neutral materials. Tall oil pitch is readily soluble in aliphatic and aromatic hydrocarbons and is compatible with a variety of oils, asphalts and rosins. Because TOP is characterized by high abundance of different fatty acids and rosin acids in addition to a variety of poorly characterized chemicals species known generally as unsaponifiables, TOP surface coatings are generally unsatisfactory for use of surface protection against the moisture and water. The TOP coatings are typically too weak and extremely tacky for commercial applications. TOP is the name for any of a number of highly viscous liquids which appear solid. In Finland crude tall oil is distilled in two distillation plants namely Arizona Chemical Oy and Forchem Oy. The total annual tall oil distillation capacity in Finland is about 300 000 tons. This will give about 100 000 tons of tall oil distillation pitch per year. These chemicals will be used in wood protection. This work has relevance to various industries involved in wood impregnation in order to protect natural and recycled wood against liquid and microbiological attack.

Summary

A general objective of the invention is to achieve a method and wooden product made thereof using safe and ecological non-mineral oil based wood protection chemicals from tall oil pitch (TOP).

First objective of the invention is to achieve a method for producing wooden products using tall oil pitch, in which tall oil pitch is in a non-tacky form. Second objective of the invention is to achieve a method for treating wooden material with tall oil pitch so that the wooden products has a satisfactory surface protection against the moisture and water.

These objectives can be achieved by the method according to claim 1 and product according to claim 22.

The method comprises treating wooden material so that said wooden material is brought into contact with a composition containing tall oil pitch liquid or emulsion of tail oil pitch so that tall oil pitch penetrates into said wooden material.

In a preferable method tall oil pitch penetrates into said wooden material so that on the surface of wooden material or inside the wooden material will form essentially non-tacky layer(s).

The product comprises a wooden material - tall oil pitch-product, produced by treating wooden material with the above method(s).

Description of the drawings

Figure 1 presents the results of a water uptake in a weathering experiment after 8 weeks exposure time. Detailed description

In this application, the term 'tall oil pitch' (TOP) refers to a non-distillable residue left from the fractionation of tall oil. The pitch, which is removed from the base of a stripping tower during a flash distillation step, is a semi- fluid, a tar-like material containing most of the higher alcohols and sterols from the original crude tall oil along with rosin and fatty acids. A typical tall oil pitch material may include 12-30% rosin acids and esters, 35-50% fatty acids and esters and 20-35% neutral materials. Tall oil pitch is readily soluble in aliphatic and aromatic hydrocarbons and is compatible with a varie- ty of oils, asphalts and rosins. Because TOP is characterized by high abundance of different fatty acids and rosin acids in addition to a variety of poorly characterized chemicals species known generally as unsaponifia- bles, TOP surface coatings are generally unsatisfactory for use of surface protection against the moisture and water. The TOP coatings are typically too weak and extremely tacky for commercial applications.

Tall oil distillation removes the low viscosity tall oil and resin acids fractions from the crude tall oil and leaves a high viscosity distillation residue called tall oil pitch (TOP).

TOP is the name for any of a number of highly viscous liquids which ap- pear solid. These chemicals will be used in wood protection. This work has relevance to various industries involved in wood impregnation in order to protect natural and recycled wood against liquid and microbiological attack.

The above described treating method of wooden material increases pri- marily the penetration depth of tall oil based products into the wood. By improving penetration depth of tall oil pitch the tendency of tall oil pitch to stain can be significantly reduced. By improving the penetration depth of tall oil pitch its effect to wooden material can be also increased remarkably as to preservability, UV resistancy (colour stability), water repellency and other properties such as strength of wooden material.

UV resistancy and strength of wooden material to be treated can further be increased by adding a suitable adhesive or UV-protective agents into the emulsion of tall oil pitch or tall oil pitch liquid. UV protective agents protecting wooden material are targeted against deterioration caused by UV radi- ation such as UV wood extractives.

The invention is also based on the general idea of treating wooden material with wood's own natural preservatives i.e. adding wood extracts into the wooden material and increasing the water proof properties of the wood by TOP of TOP emulsion. In the method according to the invention wood- en material is brought into contact with a composition including tall oil pitch liquid or emulsion of tall oil pitch. Depending on the physical properties of said composition, the result is impregnation of the wood to a certain depth either by immersion technique or pressure impregnation, surface treatment of the wood, or a combination of these. Especially the above mentioned wood treating method with a composition containing tall oil pitch emulsion allow small-sized TOP particles to penetrate into the wood and to form stable and non-tacky layers into the wood or at the surface of the wood. TOP and TOP emulsions stabilize the colour of tall oil pitch, gives UV protection and also increase the strength of treated wooden material.

In this context, the wooden material, for which the composition is intended, refers to all materials and products that contain wood material.

These material and products include raw timber, sawn timber, wooden building materials and building elements and building blocks thereof such as veneer. The wooden material refers herein also to various finished wood products (round logs, all sawn timber, such as boards, planks and laths, elements with a large surface area, such as plates, panels, blocks, wall elements, etc., furniture, outdoor furniture, and other wooden objects). Wooden material to be treated may also be present in fixed structures, particularly outdoors (wooden buildings, fences, racks, poles, bridges, piers, etc.). The wooden material also refers to a converted wood product that contains the original structure of wood for example, wood material that has been ground or chipped and reworked such as chip board, glulam, OSB (oriented strand board), cross laminated timber (CLT) and laminated veneer lumber (LVL).

The term wooden material may also comprise objects which are not completely made of wood but, for example, a combination of wood and another material, even construction materials such as concrete, stone and plastic. The invention is suitable for protecting houses, warehouses and living areas against insects, termites and fungi when simply sprayed or brushed on the protected surfaces.

The wooden material may originate to different tree species, for example pine, which is conventionally treated with CCA, for example by pressure impregnation. However, the invention is particularly well suited for tight grained wood material which is difficult to impregnate with CCA, such as spruce, if the penetration properties of the composition are adjusted to be suitable. In this way, the composition whose efficiency is at least comparable to that of CCA but which is safer for the environment can be used to improve the preservation of such types of wood which have previously not been preservable in a proper way.

The term wooden material also contains processed timber and raw timber, and the treatment thereof with the method according to invention can be given either at wood storage sites or in a separate processing mill for timber, wherein the treatment composition and the wooden material can be brought into contact in a variety of ways. Similarly, the term wooden material may also include stationary structures already erected, particularly outdoors. The method according to the invention may be used for preservation of these stationary structures, by spraying or brushing of the surfaces of these wooden materials. It should be noted that thanks to the safety of the composition, it can be used for the treatment of erected wooden structures in their locations of use without particular safety measures.

The wooden material treated by the above described method has usually a certain thickness, preferably this thickness is at least 1 mm.

The emulsion of tall oil pitch (TOP emulsion) means herein an emulsion, preferably an aqueous emulsion, wherein top oil pitch is mixed into a polar solvent such as water

The tall oil pitch liquid (TOP) means herein a highly viscous, essentially waterless tall oil pitch solution.

The solution containing TOP emulsion can be stored in unheated rooms also during winter time, because it has good resistance to freezing. Thanks to these properties, it is possible to prepare, for example, a solu- tion that is more concentrated than the above-described ready-to-use solutions, i.e. a concentrate that is suitable for storage at cold temperatures below 0 °C and which can be diluted before the use. In the preparation of such a concentrate, one should naturally take into account the solubility of the substances and in its storage recommendations the freezing point of the resulting solution.

The invention suits particularly well for treatment processes requiring good penetrability into wood, such as impregnation. The composition can be entered into the wood, for example, in the known pressure impregnation process, in which the wood is at first kept under negative pressure to remove water from its inside, after which the composition is brought into contact with the wood and its penetration into the wood is enhanced by overpressure.

Since the method of the invention enables the TOP or TOP emulsion to penetrate into wooden material , supplying additives to the composition by which the wooden material is treated, new properties may be brought into wooden material or the effect of tall oil pitch can be enhanced.

If composition used for treating wooden material includes calcium, magnesium, aluminium formate salts this further improves the termite protection of the TOP or TOP emulsion. Together with calcium, magnesium, alumini- um formate salts the invention further inhibits the absorption of water and moisture, makes the TOP or TOP emulsion even more non-tacky which are essential for avoiding biologically decomposition of wood and for practical usefulness of TOP or TOP emulsion protected wood structures. Oxi- dizing chemicals (bleaching agents) such as hydrogen peroxide, peracetic acid, performic acid, sodium percarbonate, sodium hypochlorite have been found to be surprisingly effective to diminish the original brownish colour of tall oil pitch. By this way the amount of available colouring agents i.e. colours to the end users, increase remarkably, that intensifies the commercial value of the TOP products.

The composition comprising tall oil pitch liquid or emulsion of tall oil pitch may also contain various additives, depending on the use. If the composition is to be used for surface treatment, colouring agents, such as organic colouring agents or pigments, may be added into it if the wood surface to be treated should also be given a visual change in the way of painting. In this case, for example CMC (carboxymethyl cellulose) can be used as an adhesive, which at the same time acts as a rheological auxiliary agent. The pigments and organic colouring agents are preferably free of heavy metals. For example, known iron oxide pigments can be used as the pig- ment. The physical properties of the compositions to be brushed onto the surfaces can also be selected on the basis of the use; in other words, it can be more viscose than the composition intended for impregnation, which should penetrate well into the wood. However, it should be noted that also when brushable compositions are used, some penetration of the active agents into the wood takes place (of the order of millimetres), also with viscose compositions.

The invention makes it possible to treat wood materials in a light and cost- efficient way, and the treatment can be easily included in other present- day steps of wood treatment. The process may be one step in a pro- cessing line of timber or wooden objects comprising successive steps. The composition according to the invention is also pleasant to handle, because it does not emit strongly irritating odours.

In the following, practical examples will be given of methods how the treatment composition can be used for the treatment of wood and how the treatment can be integrated in a wood material processing line in mills for wood processing.

1 ) Pressure impregnation

A conventional method for entering great amounts of impregnation substance in wood, and thereby providing the most effective treatment by means of different steps (negative pressure and overpressure, elevated temperature). By this method, the best penetrability of compositions is ob- tained, and the wood can normally be impregnated to the core. The composition according to the invention has a very good penetrability, wherein it is possible to reduce the negative pressures/overpressures used in conventional CCA impregnation and thereby to improve the cost-effectiveness of the process. Also, a tighter-grained type of wood, such as spruce, can be pressure impregnated with the composition according to the invention, which has not been possible with conventionally used substances. Pressure impregnation is suitable for TOP and TOP emulsion. Normal pressure impregnation parameters, maximum pressure ca. 10 bars at the room temperature, can be used for the treatment. Both TOP and TOP emulsion will completely penetrate into the wood, even to the core of the wood.

2) Immersion impregnation

The penetrability of the composition according to the invention is good, and especially for TOP emulsion, mere immersion impregnation is the most practical way for the treatment. This method is simple and it requires separate immersion basins and is carried out in batch processes, like the pressure impregnation. The increase of temperature fasten the penetration of TOP or TOP emulsion into the wood. For TOP emulsion at room temperature the penetration depth is few millimetres, ca. 3 mm. and at +60 C ca. 5 mm. For tall oil pitch the penetration depth can even extend to the core of the wood. The immersion impregnation using practically non aqueous tall oil pitch requires the treatment temperature over 100 C and the amount of water in the treated wood should be over 6%, preferably over 12%.

3) Spraying

The composition according to the invention can be sprayed onto the surface of wood, for example, in connection with the planing of sawn timber. In this way, preservation against microorganisms can be achieved during storage and delivery before a surface treatment (painting etc.) later on. TOP emulsion requires ca. 1 hour to dry completely. The higher concentrations of tall oil in the emulsion, requires ca. 4 hours to dry at room temperature. At elevated temperatures the drying time is few minutes.

4) Painting or other surface treatment line

The composition according to the invention may also be added into the wood in connection with a painting or another surface treatment line. From a paint dosing tank, a wooden board can be impregnated with the solution under overpressure or negative pressure through a separate painting unit. Depending on the pressure and the speed of the line, relatively good penetrability and thereby a reasonable resistance to weather can be achieved by this method. By the solution of the invention, it possible to facilitate the treatment of wood under winter conditions where the processing of frozen wood (for example, melting, impregnation, planing, painting, etc.) is problematic and constitutes an extra cost item. Both TOP compositions effectively improve the anti-freeze properties of the treated wood materials.

In still another embodiment the composition comprising TOP or TOP emulsion may also contain surfactants by means of which the distribution, the penetration of the wood preservative comes even more efficient. The use of surfactants especially increase the stability of the TOP emulsion based wood preservative and facilitates the dissolving of tall oil pitch in the emulsion i.e. prevents the phase separation in the commercial TOP emulsion.

Surfactants are wetting agents that lower the surface tension of a liquid, allowing easier spreading, and lower the interfacial tension in between two liquids. A surfactant can be classified by the presence of formally charged groups in its head. A non-ionic surfactant has no charge groups in its head. The head of an ionic surfactant carries a net charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppo- sitely charged groups, it is termed zwitterionic.

Some commonly encountered surfactants of each type include

Anionic (based on sulfate, sulfonate or carboxylate anions)

Perfluorooctanoate (PFOA or PFO), Perfluorooctanesulfonate (PFOS), Sodium dodecyl sulfate (SDS), ammonium lauryl sulfate, and oth- er alkyl sulfate salts - Sodium laureate sulfate, also known as sodium lauryl ether sulfate (SLES), Alkyl benzene sulfonate, Soaps, or fatty acid salts

Cationic (based on quaternary ammonium cations)

Cetyl trimethylammonium bromide (CTAB) a.k.a. hexadecyl trimethyl ammonium bromide, and other alkyltrimethylammonium salts, Cetyl pyridini- urn chloride (CPC), Polyethoxylated tallow amine (POEA), Benzalkonium chloride (BAC), Benzethonium chloride (BZT)

Zwittehonic (amphoteric)

Dodecyl betaine, Cocamidopropyl betaine, Coco ampho glycinate

Nonionic

Alkylpoly(ethylene oxide), Alkylphenol poly(ethylene oxide), Copolymers of poly(ethylene oxide) and polypropylene oxide) (commercially called Poloxamers or Poloxamines), Alkyl polyglucosides, including Octyl gluco- side and Decyl maltoside, Fatty alcohols including Cetyl alcohol and Oleyl alcohol, Cocamide MEA, cocamide DEA - Polysorbates (Tween 20, Tween 80) , Dodecyl dimethylamine oxide.

The preferable surfactant is anionic such as described in the international patent application WO 95/14071 .

EXAMPLES

It will be understood that while the invention has been described in conjunction with specific embodiments thereof, the foregoing description and examples are intended to illustrate, but not limit the scope of the invention. Production of tall oil pitch water emulsion

Recipe for 70 wt-% tall oil pitch water emulsion:

Chemicals:

Tall oil pitch 90 kg

Water 150 kg

· NaOH 0.24 kg

Resin (FOR90S) 1 .5 kg

Mixing:

150 kg of water was added to separate mixing vessel at the temperature of +80 - +90 C.

· 0.24 kg of NaOH was added to water until solution was clear without any precipitates.

1 .5 kg of resin (FOR90S) was mixed to solution. The resin was heated to the temperature of +80 C before mixing to the solution.

All chemicals were mixed thoroughly in the separate mixing vessel and poured to the main reactor that was connected to 1 MW steam generator.

The solution was started to mix in a dispergator until the solution was totally stabile.

At the temperature of + 80C preheated tall oil pitch (Arizona Chemicals) was added slowly to the solution. The amount of tall oil pitch was 90 kg. Dispergator was slowly mixing the solution while tall oil which was mixed into it. The cold stability of the produced TOP emulsion was tested at -18 C for 24 hours. No weakening in the dispersion or the layer formation properties was observed when TOP emulsion was recovered to normal room temperature. TOP emulsion was still water soluble and homogeneous.

Example 1 :

Immersion Treatment: Water repellency

Heat treated pine Tall oil pitch, 130 C, 2 h almost complete

Heat treated pine Tall oil pitch plus 2 wt-% Granlux GAI 45Z2, 130 C, 2 h almost complete

Heat treated spruce Tall oil pitch, 130 C, 2 h

one third

Heat treated spruce Tall oil pitch plus 2 wt-% Granlux GAI 45Z2, 130 C, 2 h one third

Heat treated Ash Tall oil pitch, 130 C, 2 h almost complete

Heat treated Ash Tall oil pitch plus 2 wt-% Granlux GAI 45Z2, 130 C, 2 h almost complete

Heat treated pine Tall oil pitch emulsion, 60 C, 2 h

one third

Heat treated pine Tall oil pitch emulsion plus 1 wt-% A Pasta Red, 60 C, 2 h one third

Heat treated spruce Tall oil pitch emulsion, 60 C, 2 h

one forth

Heat treated spruce Tall oil pitch emulsion plus 1 wt-% A Pasta Red, 60 C, 2 h one forth

Heat treated Ash Tall oil pitch emulsion, 60 C, 2 h half

Heat treated Ash Tall oil pitch emulsion plus 1 wt-% A Pasta Red, 60 C, 2 h half

Note! Water repellency was studied by dropping water droplet at surface of the treated wood sample that was cut half.

Details of the ingredients:

Tall oil pitch concentrate, TOP600, (Forchem Oy) Tall oil pith emulsion, 70 wt-% solution was diluted by water to the solution concentration of 18 wt-% (see recipe for 70 wt-% tall oil pitch water emulsion)

UV protection agent containing ΤΊ02, Granlux GAI 45Z2 (Oy Granula Ab) Coloring agent containing iron oxides, A Red Pasta (Teknos Oy)

The A Red pasta comprised hematite as a pigment. Hematite is the mineral form of iron ( III) oxide (Fe2O3), also denoted as alpha-iron oxide. Iron(lll) oxide is commonly denoted as rust. Iron(lll) oxide may be hydrated, and several hydrates of iron ( III) oxide exists. Iron(lll) oxide is insoluble in water but dissolves readily in strong acid, e.g. hydrochloric and sulfuric acids. It also dissolves well in solutions of the chelating agents such as EDTA and oxalic acid.

Analyses:

Water repellency: Tall oil and tall oil resin penetrated inside the wood structure, because the penetration of water was not observed. No crack formation was observed in the wood panels nevertheless high temperature i.e. 130 C was used especially in case of tall oil immersion impregnation.

Tackiness: The treated samples were non-tacky after the immersion treatments. The coloring agent and the UV protection agent penetrated in- side the wood. The coloring of the surfaces was uniform. In the visual examination no visual residues either from the coloring or from UV protection agents was noticed at the surfaces of the treated samples

UV stability:

The parameters for the UV stability tests were as follows: UV-cycle 4 hours, temperature +55 C, Humidity cycle 4 hours, temperature 50 C.

All test solutions improved the colour stability of the treated wood samples. No major colour changes were observed after the tests.

Polyvinyl alcohol (PVOH) and water may often be used as emulsification agents, also denoted as dispergation agents, for carbon based molecules and polymers. In particular, said products may often be used as emulsification agents for aliphatic hydrocarbon polymers, such as hydrocarbon polymers comprising a straight hydrocarbon chain. However, cyclized hydrocarbon molecules such as tall oil pitch may not be emulsified using PVOH.

Addition of a suitable rosin composition and sodium hydroxide (NaOH) may, however, be used to improve the emulsification of tall oil pitch. A suitable rosin composition may be, for example, Forchem 90S Rosin, which together with sodium hydroxide (NaOH) was in particular found to be effective for improving the emulsification of tall oil pitch.

A suitable rosin composition may comprise unmodified tall oil rosin (TOR) with high content of abietic type rosin acids, such as Forchem 90S. The properties of Forchem 90S are presented below:

Acid value min.170, typically 174 (SCAN-T 1 1 :72 method)

Colour max.WW, typically XA (ASTM D 509-98 method)

Free fatty acids typically 4% (ASTM D 5974-00 method)

Free rosin acids min.88%, typically 90% (SCAN-T 14:78 method)

Softening point min.63°C, typically 65 °C (ASTM D 6090-99 method)

Unsaponifiables typically 4% (SCAN-T 13:74 method)

Example 2:

Sample: Immersion Treatment: Water repellen- cy

Scottish pine Tall oil pitch, 130 C, 2 h

most complete

Scottish pine Tall oil pitch emulsion, 100 C, 2 h most complete

Details of the ingredients:

Tall oil pitch concentrate, TOP600, (Forchem Oy)

Tall oil pith emulsion, 70 wt-% solution was diluted by water to produce solution of 18 wt-% (see recipe for 70 wt-% tall oil pitch water emulsion}

Analyses:

Water repellency: Tall oil was totally penetrated inside the pine both in case of tall oil pitch and tall oil pitch emulsion. Good water proofing was observed for both samples. Tests clearly indicated that tall oil distillation residue remarkably improved wood hydrophobicity. Furthermore, UV-aging (254 nm) for 4 hours indicated that hydrophobicity was even more improved during the time and any exude (tacky residues) was not observed. In addition, when warming up wood after impregnation at 70 C for 4 hours wood hydrophobicity was also improved and still any exude was not observed.

Tackiness: The treated samples were non-tacky after the immersion treatment. The penetration of the tall oil inside the wood cells surprisingly reduces the tackiness of tall oil pitch concentrate and tall oil pitch emulsion. The used solution in the tests i.e. tall oil pitch and tall oil pitch emulsion formed tacky coating over the glass material that was a reference sample in order to estimate the effect of penetration depth to the tackiness.

Example 3:

Solutions:

1 ) 52 wt-% tall oil water emulsion

2) One part by weight of solution 1 ) and 1 part by weight volume of water.

3) One part by weight of solution 1 ) and 2 parts by weight volume of water.

4) Tall oil pitch

Treated wooden materials

1 ) Pine

2) Spruce from

3) Heat treated pine

4) Plywood made of spruce

All the wooden materials were treated by spreading test solutions once by a brush .

Water repellency and tackiness:

The drying of the treated wooden samples was examined visually and the tackiness of the surfaces was evaluated by checking if the paper towels attached to the treated surfaces.

The water repellency of the treated wooden samples was analyzed by the water drop test.

Tests clearly indicated that all tested both tall oil products will remarkable improve wood hydrophobicity and the water repellency. Example 4:

Solutions:

18 wt-% tall oil pitch emulsion

Treated wooden materials:

BT Wood One fire retardant treated (200 g/m2) plywood made of spruce.

BT Wood One (manufactured by BT Wood Oy) is a brushable fire retardant for wood that contains phosphorus.

Compatibility:

Tall oil emulsion was compatible with BT Wood One treated plywood. No cracking of tall oil emulsion coat or breaking of the dispersion was observed.

Example 5:

Solutions and treatment:

18 wt-% tall oil pitch emulsion / immersion at 60 C for 2 hours

Tal oil pitch / immersion at 130 CC for 2 hours

Treated wooden materials:

Heat treated spruce and pine

Strength:

Tall oil pitch emulsion and tall oil treatments increased the strength of the heat treated pine and spruce samples. When samples were cut in half no cracking or loose of strength was observed.

Example 6:

The wood material (pine) was treated by the method according to invention using either immersion impreganation or pressure impreganation. Be- low are the results:

Sample Immersion Treatment

Penetration depth [mm]

Finnish pine Tall oil pitch with 0,1 wt-% methylene blue, 130 C, 2 h to the core of the wood

Finnish pine Tall oil pitch emulsion plus 0,1 wt-% methylene blue, 80 C, 2 h 3-4 mm Sample Pressure impregnation: Penetration depth [mm]

Finnish pine Tall oil pitch plus 0,1 wt-% methylene blue, 10 bar to the core of the wood

Finnish pine Tall oil pitch emulsion plus 0,1 wt-% methylene blue, 10 bar to the core of the wood

The surfaces of the wood samples were non tacky and the water repellen- cy was excellent.

Methylene blue color (0.1 wt-%, C16H18CIN3S^*nH20, MW=319,86) was used as a coloring agent in order to estimate precisely the penetration depth of the treated wood samples. From the color change (blue color) the penetration depth was easily estimated.

Example 7:

Hydrogen peroxide was added to tall oil emulsion in order to diminish the brownish color of tall oil resin.

The needed amount of 30 wt-% H₂0₂ for 20 wt% tall oil emulsion was 16 wt-%.

After the immersion treatment (60 C, 2 hours) the wood samples made of pine were transparent (i.e. no brownish color was left the surface) and the surfaces were non tacky.

Example 8:

A weathering experiment was performed by using a QUV accelerated weathering tester to measure the protection of a treated wooden material against moisture and water. The samples were of heat treated pine (HTP) and heat treated pine comprising a brushed treatment as described in Table 1 . Sample 3 was treated with a tall oil pitch emulsion comprising hematite (iron ( III) oxide) as a pigment.

The QUV simulates the sunlight with fluorescent ultraviolet lamps, rain and dew with water spray. The weathering schedule followed the standard EN 927-6:2006 (Paint and varnishes. Coating materials and coating systems for exterior wood. Part 6: Exposure of wood coatings to artificial weathering using fluorescent UV lamps and water).

In the test, an exposure cycle of one week consists of a condensation period followed by a sub-cycle of water spray and UV-A 340 irradiation as given in Table 2. The weather experiment involves a continuous light irradiation 2.5 hours following water spray 0.5 hour. The average irradiance was 0.85 W/m² at 340 nm wavelengths. The samples were placed in the QUV without aluminium panels. Changes on the sample surfaces were estimated every 186 h. The total test time was 8 weeks (1344 hours).

The UV weathering may easily degrade the surface of a thermally modified wood product. After the UV weathering the surface of a thermally modified wood product may in addition be more prone to absorb water. Furthermore, the treatment by UV weathering may change the color of the surface of a thermally modified wood product. Protection of a treated wooden material against moisture and water was improved in the tested samples comprising tall oil pitch emulsion (20 wt-% of tall oil pitch) and offered a better protection than in the tested samples comprising commercial wood oils and wax, as shown in Table 3. Table 3 presents weight of each sample at the beginning of the experiment (week 0) and weight of each sample during the experiment after each week (Week 1 to 7), at the end of the ex- periment (Week 8), and two days after the experiment. The change in weight of the sample was determined as the weight difference of the sample at the time of measurement compared to the weight of the sample at the beginning of the test. In particular, the tall oil pitch emulsion samples comprising an organic colouring pigment improved the protection against weather and exceeded the protection of the other tested wood oils and wax. Furthermore, among the tested samples, water uptake was lowest in the samples comprising an organic colouring pigment, as shown in Figure 1 .

Samples comprising tall oil pitch emulsion samples may also be dried im- mediately after the treatment at standard room temperature. The tall oil pitch emulsion penetrates into said wooden material in such a depth that on the surface of wooden material or inside the wooden material will form essentially non-tacky layer(s). The samples comprising tall oil pitch emulsion dried without forming a tacky surface layer and could be stored in a stock pile.

Numbered items 1 to 24.

1 . A method for treating wooden material, wherein said wooden material is brought into contact with a composition containing tall oil pitch liquid or emulsion of tail oil pitch so that tall oil pitch penetrates into said wooden material.

2. The method according to item 1 , wherein tall oil pitch penetrates into said wooden material in such a depth that on the surface of wooden material or inside the wooden material will form essentially non-tacky layer(s). 3. The method according to item 1 or 2, wherein tall oil pitch contains mainly sterol alcohols and possible alcohols of fatty acids and resin acids, which alcohols are originated to tall oil.

4. The method according to item 3, wherein tall oil pitch contains 12-30 wt-% rosin acids and esters, 35-50 wt- % fatty acids and esters and 20-35 wt-% neutral materials.

5. The method according to any of the items 1 -4, wherein emulsion of tall oil pitch, preferably aqueuos emulsion of tall oil pitch is applied on the surface of wooden material.

6. The surface treating method according to item 5, wherein emulsion of tall oil pitch is prepared by mixing tall oil pitch with water in presence of emulsifying agent derived from tall oil such as rosin acids originating to tall oil.

7. The surface treating method according to any of the items 1 -6 wherein the composition to be contacted with the wooden material further contains surfactant(s) which is/are selected from a group consisting of anionic surfactants such as, sulfate, sulfonate or carboxylate containing surfactants such as sodium alkyl benzene sulphonate, sodium dodecyl sulfate, ammonium lauryl sulfate, alkyl sulfate salts such as sodium laureate sulfate, alkyl benzene sulfonate or fatty acid salts; cationic surfactants based on quaternary ammonium cations such as cetylpyridinium chloride; non-ionic surfactants such as alkyl polyglucosides, fatty alcohols including cetyl alcohol and oleyl alcohol.

8. The surface treating method according to any of the items 5 -7, wherein emulsion of tall oil pitch penetrates to certain depth of the wooden material. 9. The method according to any of the items 1 -8, wherein composition comprising tall oil pitch liquid or emulsion of tall oil pitch is impregnated into wooden material.

10. The impregnation method according to item 9, wherein tall oil pitch liquid or emulsion of tall oil pitch is impregnated into wood by possibly heating said tall oil pitch liquid or aqueous emulsion of tall oil pitch and thereafter immersing the wooden material into said possibly heated tall oil pitch liquid or aqueous emulsion of tall oil pitch.

1 1 . The impregnation method according to item 10, wherein tall oil pitch liquid is heated to temperature over 100 °C prior treating wooden material with the same and the amount of water in the treated wood is over 6%, preferably over 12%.

12. The impregnation method according to item 1 1 , wherein emulsion of tall oil pitch is heated to about from room temperature to 80 °C and then wooden material is immersed into said emulsion of tall oil pitch.

13. The impregnation method according to item 9, wherein wooden material is immersed into tall oil pitch liquid or emulsion of tall oil pitch by pressure impregnation.

14. The method according to item 13, wherein pressure and possibly al- so temperature of emulsion of tall oil pitch or tall oil pitch liquid is varied.

15. The method according to any of the previous items, wherein the quality of tall oil pitch in the composition to be contacted with wooden material and the quantity of tall oil pitch contained in the wooden material after impregnating or applying said wooden material with the composition contain- ing tall oil liquid or emulsion of tall oil pitch is such that it protects wooden material against moisture and water.

16. The method according to item 15, wherein the quality and quantity of tall oil pitch is such that it protects wooden material against microorganisms.

17. The method according to item 15 or 16 wherein wood pores are essentially filled with tall oil pitch.

18. The method according to any of the previous items wherein wooden material is treated with the composition comprising tall oil pitch liquid or emulsion of tail oil pitch and also additives selected from the group com- prising of antimicrobial agents, agents against insects such as termites, anti- cracking agent such as adhesive agent, UV protective agents protecting wooden material against deterioration caused by UV radiation, viscosi- ty modifiers, anti-oxidants, fire-retardants, free-radical capturers, bleaching agents or colouring agents such as organic colouring agents or pigments.

19. The method according to item 18, wherein the quality and quantity of tall oil pitch is such that it is compatible with P and N containing fire retard- ants such as described in patents WO 2006/072672 and WO 2010/061059.

20. The method according to item 18, wherein the agent against termites comprises formic acid salts of alkali or alkali earth metals against and is in the form of an aqueous solution or dispersion having an active ingredient concentration of 0.01 - 50% by weight, more advantageously 1 .0 - 15% by weight.

21 . The method according to item 18, wherein bleaching agent is organic peracid.

22. A wooden material - tall oil pitch-product, produced by treating wooden material with the method defined in any of the items 1 -21 .

23. A bleached wooden material - tall oil pitch- product produced according to item 22 by treating wooden material with the composition comprising tall oil pitch liquid or emulsion of tail oil pitch, preferably aqueous emulsion of tail oil pitch and also oxidizing agent.

24. A wooden material - tall oil pitch- product produced by treating wooden material with the method defined in any of the items 5 -8, wherein emulsion of tall oil pitch has been applied on the surface of wooden material so that it has been penetrated into depth of several millimetres - several centimeters into wooden material.

Claims

1 . A method for treating wooden material, wherein said wooden material is brought into contact with a composition containing tall oil pitch liquid or emulsion of tail oil pitch so that tall oil pitch penetrates into said wooden material, wherein emulsion of tall oil pitch is prepared by mixing tall oil pitch with water in presence of emulsifying agent derived from tall oil such as rosin acids originating in tall oil.

2. The method according to claim 1 , wherein wooden material is treated with the composition comprising tall oil pitch liquid or emulsion of tail oil pitch and also colouring agents such as organic colouring agents or pigments.

3. The method according to claim 1 , wherein tall oil pitch penetrates into said wooden material in such a depth that on the surface of wooden material or inside the wooden material will form essentially non-tacky layer(s).

4. The method according to any of the claims 1 - 3, wherein tall oil pitch contains mainly sterol alcohols and possible alcohols of fatty acids and resin acids, which alcohols are originated in tall oil.

5. The method according to claim 4, wherein tall oil pitch contains 12-30 wt-% rosin acids and esters, 35-50 wt- % fatty acids and esters and 20-35 wt-% neutral materials.

6. The method according to any of the claims 1 -5, wherein emulsion of tall oil pitch, preferably aqueuos emulsion of tall oil pitch is applied on the surface of wooden material.

7. The surface treating method according to claim 6, wherein emulsion of tall oil pitch is prepared by mixing tall oil pitch with water in presence of emulsifying agent derived from tall oil such as rosin acids originating in tall oil.

8. The surface treating method according to any of the claims 1 -7 wherein the composition to be contacted with the wooden material further contains surfactant(s) which is/are selected from a group consisting of anionic surfactants such as, sulfate, sulfonate or carboxylate containing surfactants such as sodium alkyl benzene sulphonate, sodium dodecyl sulfate, ammonium lauryl sulfate, alkyl sulfate salts such as sodium laureate sulfate, alkyl benzene sulfonate or fatty acid salts; cationic surfactants based on quaternary ammonium cations such as cetylpyridinium chloride; non-ionic surfactants such as alkyl polyglucosides, fatty alcohols including cetyl alcohol and oleyl alcohol.

9. The surface treating method according to any of the claims 5 -8, wherein emulsion of tall oil pitch penetrates to certain depth of the wooden material.

10. The method according to any of the claims 1 -9, wherein composition comprising tall oil pitch liquid or emulsion of tall oil pitch is impregnated into wooden material.

1 1 . The impregnation method according to claim 10, wherein tall oil pitch liquid or emulsion of tall oil pitch is impregnated into wood by possibly heating said tall oil pitch liquid or aqueous emulsion of tall oil pitch and thereafter immersing the wooden material into said possibly heated tall oil pitch liquid or aqueous emulsion of tall oil pitch.

12 The impregnation method according to claim 1 1 , wherein tall oil pitch liquid is heated to temperature over 100 °C prior treating wooden material with the same and the amount of water in the treated wood is over 6%, preferably over 12%.

13. The impregnation method according to claim 12, wherein emulsion of tall oil pitch is heated to about from room temperature to 80 °C and then wooden material is immersed into said emulsion of tall oil pitch.

14. The impregnation method according to claim 10, wherein wooden material is immersed into tall oil pitch liquid or emulsion of tall oil pitch by pressure impregnation.

15. The method according to claim 14, wherein pressure and possibly also temperature of emulsion of tall oil pitch or tall oil pitch liquid is varied.

16 The method according to any of the previous claims, wherein the quality of tall oil pitch in the composition to be contacted with wooden material and the quantity of tall oil pitch contained in the wooden material after impregnating or applying said wooden material with the composition containing tall oil liquid or emulsion of tall oil pitch is such that it protects wooden material against moisture and water.

17. The method according to claim 16, wherein the quality and quantity of tall oil pitch is such that it protects wooden material against microorganisms.

18. The method according to claim 16 or 17 wherein wood pores are essentially filled with tall oil pitch.

19. The method according to any of the previous claims wherein wooden material is treated with the composition comprising tall oil pitch liquid or emulsion of tail oil pitch and also additives selected from the group com- prising of antimicrobial agents, agents against insects such as termites, anti- cracking agent such as adhesive agent, UV protective agents protecting wooden material against deterioration caused by UV radiation, viscosity modifiers, anti-oxidants, fire-retardants, free-radical capturers, bleaching agents or colouring agents such as organic colouring agents or pigments.

20. The method according to claim 19, wherein the quality and quantity of tall oil pitch is such that it is compatible with P and N containing fire re- tardants.

21 . The method according to claim 19, wherein the agent against ter- mites comprises formic acid salts of alkali or alkali earth metals against and is in the form of an aqueous solution or dispersion having an active ingredient concentration of 0.01 - 50% by weight, more advantageously 1 .0 - 15% by weight.

22. The method according to claim 19, wherein bleaching agent is organ- ic peracid.

23. A wooden material - tall oil pitch-product, produced by treating wooden material with the method defined in any of the claims 1 -22.

24. A bleached wooden material - tall oil pitch- product produced according to claim 23 by treating wooden material with the composition com- prising tall oil pitch liquid or emulsion of tail oil pitch, preferably aqueous emulsion of tail oil pitch and also oxidizing agent.

25. A wooden material - tall oil pitch- product produced by treating wooden material with the method defined in any of the claims 6 -9, wherein emulsion of tall oil pitch has been applied on the surface of wooden material so that it has been penetrated into depth of several millimetres - several centimeters into wooden material.