Wood preservative compositions

FIELD OF THE INVENTION

[0001] The present invention relates to the preservation of wood products. More specifically, the invention relates to the preservation of wood products from the attack of termites.

BACKGROUND OF THE INVENTION

[0002] The preservation of timber against the attack of termites and other insect pests is a major undertaking because of the great damage inflicted by insects to stored timber and to wood and wood products, e.g., wood that is part of buildings or outdoor constructions.

[0003] Bromophenols have not been used in order to protect wood products from termites. One preferred illustrative compound of this class is Tetrabromobisphenol A (hereinafter referred to as “TBBA”) which is a fire-retardant material, widely employed for protecting plastics against fire. JP 61-6769 (Publication No. 55-159915) discloses the coating of a single wood plate with TBBA as a protection against mould.

[0004] It is an object of the present invention to provide a family of brominated phenols that can be used for protecting wood and wood products against insect attack, particularly against termites.

[0005] It is another object of the invention to provide solutions of insecticidal and termiticidal bromophenols that can be used to impregnate wood or wood products.

[0006] Other purposes and advantages of the invention will appear as the description proceeds.

SUMMARY OF THE INVENTION

[0007] The invention is directed to an insecticidal and termiticidal wood preservative composition containing as an active ingredient a compound of the formula:

[0008] wherein Y is a moiety selected from halogen, substituted aromatic ring and/or aliphatic residue, and n-1 to 4.

[0009] A preferred class of compounds useful in the composition of the invention in that in which Y is

[0010] wherein X is a moiety selected from alkylidene, NH, S or SO2, and m=0 to 4.

[0011] According to a preferred embodiment of the invention the compound of Formula (I) is selected from among tetrabromobisphenol A (TBBA), tribromobisphenol A (TBA), or a bromine derivative of a compound selected from Bisphenol F, Bisphenol A, Bisphenol S, Bisphenol Z, 4,4′-Biphenol, 1,1,2,2-tetra-(4-hydroxyphenyl) ethane, 2,2-hexafluoroisopropylidenediphenol, 1,1-ethylidenediphenol, 1,1-propylidenediphenol, or

[0012] The insecticidal and termiticidal composition of the invention is conveniently dissolved in a solvent prior to impregnation into the wood. Different solvents are suitable for this purpose. Illustrative and non-limitative preferred solvents are ethanol and aqueous basic solutions, e.g., in which the base is NaOH.

[0013] According to a preferred embodiment of the invention the active material is TBBA and its concentration ranges between 1% (w/w) and 20% (w/w), preferably between about 3% and 10%.

[0014] The composition of the invention may further comprise conventional termiticidal and insecticidal agents which are well known to the skilled person.

[0015] In another aspect the invention is directed to a method for protecting wood against termites, comprising impregnating the wood with a wood preservative composition as described above. The term “protection”, as used herein, includes both the repulsion of termites away from the wood, and the actual killing thereof.

[0016] The present invention provides for a long-term protection of wood and wood products against termites by impregnating, e.g., by pressure-impregnation, the wood with an active ingredient, e.g. TBBA, the latter being dissolved either in an aqueous solvent or in an organic solvent or micro-emulsion. It should be appreciated that superficial coating of the wood with the active ingredient is not sufficient to achieve long-term protection, and therefore the invention is meant to relate to the in-depth impregnation of the wood with said active material. The actual depth of penetration of the active material will depend on many factors, as will be apparent to the skilled person, such as the type of wood or wood product, the type of solution, the pressure employed, etc. However, the invention encompasses all cases in which at least some impregnation of the wood, below the surface, is achieved.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The aforementioned characteristics and advantages of the invention will be better understood through the following illustrative and non-limitative examples of preferred embodiments thereof.

EXAMPLE 1

[0018] Method

[0019] The termiticidal and/or termite repellency effect of TBBA was examined by field exposure of TBBA treated timber samples to an active population of termites (Macrotermes natalensis). Much of the test detail (timber specimen species, dimensions, preservative impregnation method, scoring system etc.) was based on the European laboratory standard EN 117. This standard is used to define the toxic values of wood preservative formulations against wood destroying termites of the species Reticulitermes santonensis.

[0020] The TBBA active was formulated as a solvent-borne product for the test. (ethanol carrier). The precise preservative solutions used were 0% (ethanol only), 1% TBBA, 3% TBBA, 5% TBBA, 7% TBBA and 10% TBBA (all w/w).

[0021] AU wood block specimens were of Scots pine sapwood (Pinus sylvestris) with dimensions of 50×25×15 mm. All the test blocks were vacuum impregnated with TBBA according to the method of EN 117. Distribution of the treated blocks in the test was as follows:

[0022] Treated Specimens (TS):

[0023] 3 (replicate specimens)×5 (TBBA conc.s)=15 (no.s 34-48)

[0024] Solvent Control Specimens (SCS):

[0025] 3 (replicate specimens)×1 (conc. (i.e. 0% (ethanol only))=3 (no.s 49-51)

[0026] Untreated Control Specimens (UCS) (Virulence): =3 (no.s 70-72)

[0027] TS Specimens: to determine the efficacy of the TBBA active (at different concentrations) against termite attack. SCS Specimens: to confirm absence of a termiticidal effect by the TBBA carrier (ethanol). UCS Specimens: to establish the virulence of the field population of termites.

[0028] The termite field site was established in Ginginglovu (Zululand, South Africa). The soil type of the area was a Hutton Bush Veldt soil (sandy loam soil). The site was situated within 10 m of an active termite mound on a raised flat platform of soil established some 5 cm above ground level. The test specimens were randomly positioned on this platform and carefully covered with a waterproof flat plastic roof. This plastic roof was covered with soil to allow temperature and humidity conditions within the test zone to remain representative of the locale. The test specimens were left in-situ for a period of 54 days then scored for termite attack according the system defined in European standard EN 117 as follows:

[0029] Score 0: No attack

[0030] Score 1: Attempted attack

[0031] Score 2: Slight attack

[0032] Score 3: Average attack

[0033] Score 4: Strong attack

[0034] Results

[0035] Table I displays mean termite attack scores (and high scores) for TBBA treated test specimens (ethanol carrier) after 54 days exposure to a field population of the termite Macrotermes natalensis. Table II displays mean termite attack scores (and high scores) for untreated virulence control specimens after 54 days exposure to a field population of the termite Macrotermes natalensis. In both tables, standard deviations are presented in the first parenthesis and the second parenthesis shows the highest score out of 3 replicates.

[0036] Table II shows a mean score of 2.67 (high score of 3) clearly indicating that the termite population at the site was very active and virulent. Table I shows that after 54 days exposure, of wood block specimens treated with solvent-borne TBBA at concentrations of 1%, 3%, 5%, 7% and 10%, only 1 block (of 3) treated with 7% had received any form of attack. The results for blocks treated with solvent only were severely attacked, indicating that the preservative carrier provided no protection. Under the scoring conditions of EN 117 therefore, the results indicate that the toxic values of solvent borne TBBA against termite attack lie between 1% and 10%.

1TABLE ITBBATreatedMean TermiteConcentrationsSpecimenAttack Scorestudied (%)Numbers(0-4)10 34-360.00 (0.00) (0)737-390.33 (0.58) (1)540-420.00 (0.00) (0)343-450.00 (0.00) (0)146-480.00 (0.00) (0)049-512.33 (0.58) (3)

[0037]

2

TABLE II

Treated
Mean Termite

Specimen
Attack Score

Numbers
(0-4)

70-72
2.67 (0.58) (3)

EXAMPLE 2

[0038] Method

[0039] A laboratory test was undertaken to determine the toxic values of novel actives against termites. The active materials used were TBBA, TBBE [4,4′-ethylidenebis(2,6-dibromophenol)] [CAS RN=12639-25-3] (Sample Number 1392-82-03); TBBZ [4,4′-cyclohexylidene(2,6-dibromophenol)] [CAS RN=53350-96-2] (Sample Number 1392-72-03) and TBA, 2,2′,6-tribromo-4,4′-isopropylidenediphenol, CAS 6386-73-8 (Sample Number 1392-75-03).

[0040] The test was undertaken largely according to the strictures laid down in ASTM 3345-74 (the American standard laboratory test to assess the termite resistant properties of wood to wood destroying termites). The test method allows for the exposure of treated buried wood blocks to termites (Reticulitermes or Coptotermes spp.) over a period of 4 weeks. Efficacy of the product is determined by the extent of termite damage to the treated timber specimens through a scoring system. The test was slightly modified from the standard ASTM test by reducing the number of replicate wood specimens from 5 to 4. In addition, the ASTM scoring system was replaced by the more objective scoring system of the similar European standard EN 117 as follows:

[0041] Score 0: No attack

[0042] Score 1: Attempted attack

[0043] Score 2: Slight attack

[0044] Score 3: Average attack

[0045] Score 4: Strong attack

[0046] The toxic values of the preservative product (in kg/m3 of wood) fall between two values as follows:

[0047] 1) The lowest concentration which protects the wood (i.e. the concentration at which none of the test specimens show a degree of attack greater than 1).

[0048] 2) The next lowest concentration in the series used at which the wood is no longer sufficiently protected (i.e. the concentration at which at least one test specimen shows a degree of attack of 2 or greater).

[0049] The validity of the test is confirmed if at least 2 of the untreated control specimens and at least 2 of the solvent/diluent control specimens correspond to a damage score of 4, and the corresponding colonies have at least 50% survivors.

[0050] The termites employed were Coptotermes formosanus.

[0051] The treatment solutions tested were:

[0052] TBBA (Ethanol Carrier): 10%, 7%, 5%, 3% and 1%

[0053] TBBE (Ethanol Carrier): 10%, 7%, 5%, 3% and 1%

[0054] TBBZ (Ethanol Carrier): 10%, 7%, 5%, 3% and 1%

[0055] TBA (Ethanol Carrier): 10%, 7%, 5%, 3% and 1%

[0056] Ethanol Control

[0057] All wood bock specimens were of Southern Yellow Pine sapwood (Pinus spp.) with dimensions of 25.4×25.4×6.4 mm in accordance with ASTM D3345-74. All blocks were vacuum impregnated with the relevant solutions in accordance with ASTM D3345-74. Distribution of blocks in the test was as follows:

[0058] TBBA: 4 (specimens)×5 (conc.)=20 (block no.s 21-40)

[0059] TBBE: 4 (specimens)×5 (conc.)=20 (block no.s 61-80)

[0060] TBBZ: 4 (specimens)×5 (conc.)=20 (block no.s 81-100)

[0061] TBA: 4 (specimens)×5 (conc.)=20 (block no.s 101-120)

[0062] Ethanol Control: 4 (specimens)=4 (block no.s 181-184)

[0063] Ethanol controls were used to establish both the absence of any termicidal effect due to the ethanol carrier and the virulence of the termites used in the test.

[0064] The test specimens were conditioned and subjected to a leaching schedule (after vacuum impregnation) as stipulated in ASTM D1413-76 (as recommended in ASTM D3345-74). All test specimens were then air dried for two weeks to constant weight.

[0065] The specimens were each positioned at the base of a 500 ml polyethylene culture jar (numbered according to each test specimen) and covered with 200 g of sand (pre-washed, sterilised and air conditioned in the laboratory) to which was added 25 g of de-ionised water. A further two containers containing watered sand but no timber were also prepared. All the jars were sealed (lids pre-pierced and covered with stainless steel mesh for aeration).

[0066] Two days after specimen placement, 200 termites were added to each culture jar (90% workers and 10% soldiers) and the jars re-sealed. The jars were incubated at a mean temperature and relative humidity of 27.5° C. and 75-90% for 4 weeks. The containers were provided with an artificial lighting regime of 10 hours light and 14 hours darkness.

[0067] After 1 week and 4 weeks each container was examined to determine termite mortality and normal tunneling behaviour patterns as follows:

[0068] Is there tunneling present: YES/NO

[0069] Are there any termites on the surface of the soil: YES/NO (if yes how many, i.e. 1-25% of pop, 26-50% of pop, 51-100% of pop.)

[0070] Are any dead termites visible: YES/NO (if yes how many, 1-33%, 34-66%, 67-100%)

[0071] After 4 weeks the test specimens were removed and cleaned of debris. Each block was examined and visually rated for termite damage using the scoring system detailed above.

[0072] Results

[0073] Table III shows termite attack ratings on wood specimens treated with ethanol after 4 weeks incubation in sand culture.

[0074] Tables IV, V, VI and VII show termite attack ratings on wood specimens treated with TBBA, TBBE, TBBZ and TBA respectively, after 4 weeks incubation in sand culture.

[0075] Table IIa shows tunneling activity, surface activity and mortality of termites after 1 and 4 weeks exposure in sand culture to wood specimens treated with ethanol.

[0076] Tables IVa, Va, VIIa and VIIa show tunneling activity, surface activity and mortality of termites after 1 and 4 weeks exposure in sand culture to wood specimens treated with TBBA, TBBE, TBBZ and TBA respectively.

[0077] Ethanol Specimens: Table m shows that the termites used in the test were virulent (and were not affected by ethanol treatment of these specimens) with 2 of the 4 test specimens suffering strong attack. This was to be expected as table IIIa shows that the termites thrived under the test conditions with tunneling activity and complete survival noted throughout the test period.

[0078] TBBA Specimens: Table IV shows that the toxic values of TBBA are 32.52 and 44.00 kg/m3 (solution concentrations of 5 and 7%). The score of 2 for one of the test specimens, at a mean loading of 55.26 kg/m3, is disregarded as an anomalous result. The surface activity data in table IVa indicates that the two highest TBBA concentrations (7 and 10%) resulted in a degree of termite repellency throughout the incubation period. In addition, the three highest concentrations (5, 7 and 10%) resulted in very significant termite mortality (generally 67-100%) by the end of the incubation period.

[0079] TBBE Specimens: Table V shows that the toxic values of TBBE are 28.53 and 35.93 kg/M3 (solution concentrations of 5 and 7%). The surface activity noted in table Va indicates that TBBE provided a repellent effect at certain stages of the incubation period. The highest concentration of TBBE (10%) resulted in 67-100% termite mortality by the end of the incubation period.

[0080] TBBZ Specimens: The presence of individual ratings of 2 at the three highest concentrations prevented the determination of toxic values for this active (Table VI). However, it is clear that the higher concentrations do reduce termite attack. TBBE also provided a repellent effect early in the incubation period at higher concentrations and resulted in significant termite mortality by the end of the incubation period (table VIa).

[0081] TBA Specimens: Table VII shows that the toxic values of TBA are 30.17 and 41.22 kg/m3 (solution concentrations of 5 and 7%). TBA produced no repellent effect on the termite population but the higher concentrations resulted in 34-66% termite mortality by the end of the incubation period (table VIIa).

3TABLE IIITermite AttackMeanSpecimen No.RatingRating18133.501824(0.58)18341843

[0082]

4

TABLE IV

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

21
10
48.0565
54.28
1
1.00

22
10
56.3233
(4.95)
1
(0.00)

23
10
59.6759

1

24
10
53.0682

1

25
7
39.6153
35.93
1
1.00

26
7
35.6604
(2.70)
1
(0.00)

27
7
33.1234

1

28
7
35.3348

1

29
5
30.0848
28.53
1
1.50

30
5
28.1562
(2.39)
1
(0.58)

31
5
25.3130

2

32
5
30.5730

2

33
3
17.7648
17.78
2
2.25

34
3
16.4121
(1.11)
2
(0.50)

35
3
17.8172

3

36
3
19.1350

2

37
1
7.5465
6.94
3
2.75

38
1
6.8405
(0.41)
2
(0.95)

39
1
6.6395

4

40
1
6.7444

2

[0083]

5

TABLE V

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

61
10
51.7924
55.26
1
1.25

62
10
59.9261
(5.35)
1
(0.50)

63
10
49.5835

1

64
10
59.7234

2

65
7
42.7084
44.00
1
1.00

66
7
46.2477
(1.77)
1
(0.00)

67
7
42.4744

1

68
7
44.5619

1

69
5
33.4407
32.52
2
1.50

70
5
30.9586
(1.11)
1
(0.58)

71
5
33.1791

1

72
5
32.5056

2

73
3
17.1295
17.94
2
2.00

74
3
17.4279
(1.12)
2
(0.82)

75
3
17.6150

3

76
3
19.5934

1

77
1
5.7355
5.62
3
3.00

78
1
5.8468
(0.23)
3
(0.00)

79
1
5.5676

3

80
1
5.3174

3

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3: Average Attack/4: Strong Attack

[0084]

6

TABLE VI

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

81
10
56.1953
56.09
1
1.25

82
10
56.5116
(0.34)
1
(0.50)

83
10
55.8560

1

84
10
55.7841

2

85
7
37.8957
39.36
1
1.25

86
7
35.8088
(3.17)
1
(0.50)

87
7
43.1990

2

88
7
40.1507

1

89
5
29.1654
28.54
1
1.25

90
5
30.1080
(1.47)
1
(0.50)

91
5
28.2496

1

92
5
26.6558

2

93
3
18.8209
16.96
2
1.50

94
3
18.9218
(2.40)
1
(0.58)

95
3
13.8822

2

96
3
16.2365

1

97
1
5.6620
5.95
4
2.50

98
1
5.0941
(0.71)
2
(1.00)

99
1
6.4104

2

100
1
6.6534

2

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3:Average Attack/4: Strong Attack

[0085]

7

TABLE VII

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

101
10
62.5923
55.10
1
1.00

102
10
56.2025
(6.25)
1
(0.00)

103
10
54.1902

1

104
10
47.4157

1

105
7
40.2913
41.22
1
1.00

106
7
37.8605
(2.84)
1
(0.00)

107
7
44.5498

1

108
7
42.1750

1

109
5
29.4314
30.17
2
1.75

110
5
31.2399
(0.78)
1
(0.50)

111
5
30.1471

2

112
5
29.8682

2

113
3
17.8751
18.41
2
1.75

114
3
18.3913
(1.71)
2
(0.50)

115
3
20.7329

1

116
3
16.6446

2

117
1
5.2534
5.82
3
3.00

118
1
6.1841
(0.58)
2
(0.82)

119
1
5.3939

3

120
1
6.4328

4

[0086]

8

TABLE IIIa

Tunneling
Surface
Visible

Specimen
Activity
Activity
Mortality

No.
(1 week)
(1 week)
(1 week)

181
Yes
No
No

182
Yes
No
No

183
Yes
No
No

184
Yes
No
No

Tunneling
Surface
Visible

Specimen
Activity
Activity
Mortality

No.
(4 weeks)
(4 weeks)
(4 weeks)

181
Yes
No
No

182
Yes
No
No

183
Yes
No
No

184
Yes
No
No

[0087]

9

TABLE IVa

Tunneling
Surface
Visible

Specimen
Activity (¼
Activity (¼
Mortality (¼

No.
weeks)
weeks)
weeks)

21
Yes/Yes
No/1-25% (of pop.)
No/67-100% (of

pop.)

22
Yes/Yes
No/1-25% (of pop.)
No/67-100% (of

pop.)

23
Yes/Yes
No/1-25% (of pop.)
No/67-100% (of

pop.)

24
Yes/Yes
No/1-25% (of pop.)
No/67-100% (of

pop.)

25
Yes/Yes
No/No
No/1-33% (of pop.)

26
Yes/Yes
No/No
No/1-33% (of pop.)

27
Yes/Yes
No/No
No/1-33% (of pop.)

28
Yes/Yes
No/No
No/1-33% (of pop.)

29
Yes/Yes
1-25%/No (of pop.)
1-33%/1-33% (of

pop.)

30
Yes/Yes
1-25%/No (of pop.)
1-33%/1-33% (of

pop.)

31
Yes/Yes
1-25%/No (of pop.)
No/1-33% (of pop.)

32
Yes/Yes
1-25%/No (of pop.)
No/1-33% (of pop.)

33
Yes/Yes
No/No
No/1-33% (of pop.)

34
Yes/Yes
No/No
No/1-33% (of pop.)

35
Yes/Yes
No/No
No/No

36
Yes/Yes
No/No
No/No

37
Yes/Yes
No/No
No/No

38
Yes/Yes
No/No
No/No

39
Yes/Yes
No/No
No/No

40
Yes/Yes
No/No
No/No

[0088]

10

TABLE Va

Tunneling
Surface
Visible

Specimen
Activity (¼
Activity (¼
Mortality (¼

No.
weeks)
weeks)
weeks)

61
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

62
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

63
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

64
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

65
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

66
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

67
Yes/Yes
1-25%/1-25% (of
1-33%/67-100% (of

pop.)
pop.)

68
Yes/Yes
1-25%/1-25% (of
No/67-100% (of

pop.)
pop.)

69
Yes/Yes
No/No
No/67-100% (of

pop.)

70
Yes/Yes
No/No
No/67-100% (of

pop.)

71
Yes/Yes
No/No
No/34-66% (of pop.)

72
Yes/Yes
No/No
No/1-33% (of pop.)

73
Yes/Yes
No/No
No/1-33% (of pop.)

74
Yes/Yes
No/No
No/1-33% (of pop.)

75
Yes/Yes
No/No
No/1-33% (of pop.)

76
Yes/Yes
No/No
No/1-33% (of pop.)

77
Yes/Yes
No/No
No/No

78
Yes/Yes
No/No
No/No

79
Yes/Yes
No/No
No/No

80
Yes/Yes
No/No
No/No

[0089]

11

TABLE VIa

Tunneling
Surface
Visible

Activity
Activity
Mortality

Specimen
(¼
(¼
(¼

No.
weeks)
weeks)
weeks)

81
Yes/Yes
1-25%/No (of pop.)
No/67-100% (of

pop.)

82
Yes/Yes
1-25%/No (of pop.)
No/67-100% (of

pop.)

83
Yes/Yes
1-25%/No (of pop.)
No/67-100% (of

pop.)

84
Yes/Yes
1-25%/No (of pop.)
No/67-100% (of

pop.)

85
Yes/Yes
1-25%/No (of pop.)
No/34-66% (of pop.)

86
Yes/Yes
1-25%/No (of pop.)
No/34-66% (of pop.)

87
Yes/Yes
1-25%/No (of pop.)
No/34-66% (of pop.)

88
Yes/Yes
1-25%/No (of pop.)
No/34-66% (of pop.)

89
Yes/Yes
No/No
No/34-66% (of pop.)

90
Yes/Yes
No/No
No/34-66% (of pop.)

91
Yes/Yes
No/No
No/34-66% (of pop.)

92
Yes/Yes
No/No
No/34-66% (of pop.)

93
Yes/Yes
No/No
No/1-33% (of pop.)

94
Yes/Yes
No/No
No/1-33% (of pop.)

95
Yes/Yes
No/No
No/1-33% (of pop.)

96
Yes/Yes
No/No
No/1-33% (of pop.)

97
Yes/Yes
No/No
No/No

98
Yes/Yes
No/No
No/No

99
Yes/Yes
No/No
No/No

100
Yes/Yes
No/No
No/No

[0090]

12

TABLE VIIa

Tunneling
Surface
Visible

Specimen
Activity (¼
Activity (¼
Mortality (¼

No.
weeks)
weeks)
weeks)

101
Yes/Yes
No/No
No/34-66% (of pop.)

102
Yes/Yes
No/No
No/34-66% (of pop.)

103
Yes/Yes
No/No
No/34-66% (of pop.)

104
Yes/Yes
No/No
No/34-66% (of pop.)

105
Yes/Yes
No/No
No/34-66% (of pop.)

106
Yes/Yes
No/No
No/34-66% (of pop.)

107
Yes/Yes
No/No
No/34-66% (of pop.)

108
Yes/Yes
No/No
No/34-66% (of pop.)

109
Yes/Yes
No/No
No/34-66% (of pop.)

110
Yes/Yes
No/No
No/34-66% (of pop.)

111
Yes/Yes
No/No
No/34-66% (of pop.)

112
Yes/Yes
No/No
No/34-66% (of pop.)

113
Yes/Yes
No/No
No/1-33% (of pop.)

114
Yes/Yes
No/No
No/1-33% (of pop.)

115
Yes/Yes
No/No
No/1-33% (of pop.)

116
Yes/Yes
No/No
No/1-33% (of pop.)

117
Yes/Yes
No/No
No/No

118
Yes/Yes
No/No
No/No

119
Yes/Yes
No/No
No/No

120
Yes/Yes
No/No
No/No

[0091] From the reported results, the following conclusions may, inter alia, be reached:

[0092] 1) Impregnation of test specimens with concentrated solutions of TBBA, TBBE, TBBZ and TBA, followed by leaching, resulted in a significant reduction in termite attack.

[0093] 2) Impregnation of test specimens with concentrated solutions of TBBA, TBBE and TBBZ resulted in a degree of termite repellency and the highest treatment concentrations of TBBA, TBBE, TBBZ and TBA generally resulted in 67-100% mortality of the termite population by the end of the trial.

EXAMPLE 3

[0094] Method

[0095] A further experiment was undertaken according to the modified ASTM 3345-74 test detailed in Example 2 with the following 6 changes to the protocol:

[0096] 1. The solutions tested were as follows:

[0097] TBBA (NaOH Carrier): 10%, 7%, 5%, 3% and 1%

[0098] TBBF (NaOH Carrier): 10%, 7%, 5%, 3% and 1%

[0099] TBBS (NaOH Carrier): 10%, 7%, 5%, 3% and 1%

[0100] NaOH Carrier Control: 10%, 7%, 5%, 3% and 1%

[0101] H2O Control

[0102] Untreated Control

[0103] 2. The incubation substrate was a soil/sand mixture (1:1) to which had been added 75 ml of de-ionised water. This substrate was chosen as being more representative of the laboratory conditions under which the wild caught termites (C. formosanus) were maintained.

[0104] 3. The treated timber samples were positioned on plastic mesh on top of the soil substrate. This method of placement is that used in European Standard EN 117 and is more representative of the feeding conditions of the wild caught termites maintained in the laboratory.

[0105] 4. 250 termites were used in each incubation vessel.

[0106] 5. The wood block specimens were not subjected to a leaching process.

[0107] 6. Evidence of termite tunneling activity and mortality was determined at completion of the incubation period only (4 weeks) and no examinations were undertaken for surface activity.

[0108] Distribution of blocks in the test was as follows:

[0109] TBBA: 4 (specimens)×5 (conc.)=20 (block no.s 41-60)

[0110] TBBF: 4 (specimens)×5 (conc.)=20 (block no.s 121-140)

[0111] TBBS: 4 (specimens)×5 (conc.)=20 (block no.s 141-160)

[0112] NaOH Carrier Control: 1 (specimen)×5 (conc.)=5 (blocks 163/165/172/174/179)

[0113] H2O Control: 4 (specimens)=4 (block no.s 185-188)

[0114] Untreated Control: 4 (specimens)=4 (block no.s 189-192)

[0115] NaOH Carrier, H2O and untreated controls were used to establish both the absence of any termiticidal effect due to the NaOH carrier solution and the virulence of the termites used in the test.

[0116] Results

[0117] Table VIII shows termite attack ratings on untreated wood specimens after 4 weeks incubation in soil/sand culture.

[0118] Table IX shows termite attack ratings on wood specimens treated with de-ionised water after 4 weeks incubation in soil/sand culture.

[0119] Tables X, XI and XII show termite attack ratings on wood specimens treated with TBBA, TBBF and TBBS respectively, after 4 weeks incubation in soil/sand culture.

[0120] Table XIII shows termite attack ratings on wood specimens treated with NaOH carrier solutions after 4 weeks incubation in soil/sand culture.

[0121] Table VIIIa shows tunneling activity and mortality of termites after 4 weeks exposure in soil/sand culture to untreated wood specimens.

[0122] Table IXa shows tunneling activity and mortality of termites after 4 weeks exposure in soil/sand culture to wood specimens treated with de-ionised water.

[0123] Tables Xa, XIa and XIIa show tunneling activity and mortality of termites after 4 weeks exposure in soil/sand culture to wood specimens treated with TBBA, TBBF and TBBS respectively.

[0124] Table XIIa shows tunneling activity and mortality of termites after 4 weeks exposure in soil/sand culture to wood specimens treated with NaOH carrier solutions.

[0125] Control Specimens: Tables VII and IX (untreated and water treated specimens) show that the termites used in the test were highly virulent with 3 of the 8 test specimens suffering the highest level of attack according to the rating system. In addition, Table XIII shows that none of the NaOH control specimens, except that treated with the highest concentration of NaOH, escaped the highest level of attack. Tables VIIa, IXa and XIIIa show that the high level of attack experienced by all the foregoing test specimens was clearly due to the test conditions favoring termite survival with the great majority of the termites active at the end of the test period.

[0126] TBBA Specimens: Table X shows that the upper mean toxic value of TBBA, according to these test results, was 6.97 kg/m8 (solution concentration of 1%). The data indicate that significant attack was prevented by all concentrations of TBBA used. Despite this low level of attack, table Xa shows that the majority of the termites were still active at the end of the test period. TBBA appeared therefore to be acting as a repellent throughout the trial period. This is supported by the observation that the termites had only partially soil covered those test specimens treated with 5, 7 and 10% solutions of TBBA, while those specimens treated with the lower concentrations were invariably completely covered.

[0127] TBBF Specimens: Table XI shows that the toxic values of TBBF are 6.78 and 20.53 kg/m3 (solution concentrations of 1 and 3%). The data again indicate that significant attack was prevented by all concentrations of TBBF used. Table XIa shows that the majority of the termites were killed by the end of the test period indicating a significant termiticidal effect. However, as was found for TBBA, those test specimens treated with 5, 7 and 10% solutions of TBBF were only partially soil covered at the end of the test, thereby demonstrating a repellent effect also.

[0128] TBBS Specimens: Table XII shows that the upper mean toxic value of TBBA, according to these test results, was 7.27 kg/M3 (solution concentration of 1%). As shown for both TBBA and TBBF, significant attack was prevented by all concentrations of TBBS used. Table XIIa shows that exposure to TBBS resulted in significant termite mortality by the end of the test period. Once more a repellent effect was noted with test specimens treated with 5, 7 and 10% solutions of TBBS being partially soil covered at the end of the test.

13TABLE VIIITermite AttackMeanSpecimen No.RatingRating18942.751902(0.96)19131922

[0129]

14

TABLE IX

Termite Attack
Mean

Specimen No.
Rating
Rating

185
4
3.00

186
2
(1.15)

187
4

188
2

[0130]

15

TABLE X

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

41
10
74.6900
71.14
1
1.00

42
10
65.7449
(3.86)
1
(0.00)

43
10
71.2935

1

44
10
72.8397

1

45
7
49.5152
51.69
1
0.75

46
7
54.1000
(1.88)
1
(0.50)

47
7
51.5702

0

48
7
51.5850

1

49
5
35.8990
36.78
1
1.00

50
5
36.4348
(1.19)
1
(0.00)

51
5
36.2667

1

52
5
38.5379

1

53
3
20.9089
22.40
1
1.00

54
3
23.6298
(1.18)
1
(0.00)

55
3
22.0586

1

56
3
22.9877

1

57
1
7.1182
6.97
1
1.00

58
1
7.1204
(0.33)
1
(0.00)

59
1
7.1712

1

60
1
6.4710

1

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3: Average Attack/4: Strong Attack

[0131]

16

TABLE XI

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

121
10
61.1175
56.07
1
0.5

122
10
54.6652
(5.21)
0
(0.58)

123
10
49.3758

0

124
10
59.1172

1

125
7
45.6618
38.61
1
0.75

126
7
37.4983
(5.62)
0
(0.50)

127
7
32.0221

1

128
7
39.2380

1

129
5
25.7958
29.91
0
0.5

130
5
33.5691
(3.20)
0
(0.58)

131
5
30.5580

1

132
5
29.7245

1

133
3
21.1138
20.53
0
0.75

134
3
22.3233
(1.61)
1
(0.50)

135
3
20.1881

1

136
3
18.4960

1

137
1
7.0290
6.78
3
1.50

138
1
6.6132
(0.51)
1
(1.00)

139
1
6.1630

1

140
1
7.3321

1

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3: Average Attack/4: Strong Attack

[0132]

17

TABLE XII

Termite

Specimen
Solution
Loading
Mean
Attack
Mean

No.
Conc. (%)
(kg/m3)
(kg/m3)
Rating
Rating

141
10
66.4361
68.25
0
0.25

142
10
59.5467
(6.98)
0
(0.50)

143
10
75.9517

0

144
10
71.0662

1

145
7
55.0388
48.81
1
0.75

146
7
45.9981
(7.61)
1
(0.50)

147
7
39.3169

0

148
7
54.8711

1

149
5
31.9904
34.70
1
1.00

150
5
34.6792
(1.96)
1
(0.00)

151
5
35.5325

1

152
5
36.5564

1

153
3
19.4698
20.11
1
0.5

154
3
21.3925
(1.71)
0
(0.58)

155
3
21.5804

0

156
3
17.9846

1

157
1
7.2622
7.25
1
1.00

158
1
6.7354
(0.48)
1
(0.00)

159
1
7.8894

1

160
1
7.1311

1

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3: Average Attack/4: Strong Attack

[0133]

18

TABLE XIII

Specimen
Solution Conc.
Termite

No.
(%) Eq.
Attack Rating

163
10
1

165
7
4

172
5
4

174
3
4

179
1
4

NB: 0: No Attack/1: Attempted Attack/2: Slight Attack/3: Average Attack/4: Strong Attack

[0134]

19

TABLE VIIIa

Specimen
Tunneling
Visible

No.
Activity
Mortality

189
Yes
1-33%

190
Yes
1-33%

191
Yes
1-33%

192
Yes
1-33%

[0135]

20

TABLE IXa

Specimen
Tunneling
Visible

No.
Activity
Mortality

185
Yes
1-33%

186
Yes
1-33%

187
Yes
1-33%

188
Yes
1-33%

[0136]

21

TABLE Xa

Specimen
Tunneling
Visible

No.
Activity
Mortality

41
Yes
1-33%

42
Yes
1-33%

43
Yes
1-33%

44
Yes
1-33%

45
Yes
1-33%

46
Yes
1-33%

47
Yes
1-33%

48
Yes
1-33%

49
Yes
1-33%

50
Yes
1-33%

51
Yes
1-33%

52
Yes
1-33%

53
Yes
1-33%

54
Yes
1-33%

55
Yes
1-33%

56
Yes
1-33%

57
Yes
No

58
Yes
No

59
Yes
No

60
Yes
No

[0137]

22

TABLE XIa

Specimen
Tunneling
Visible

No.
Activity
Mortality

121
Yes
67-100%

122
Yes
67-100%

123
Yes
67-100%

124
Yes
67-100%

125
Yes
67-100%

126
Yes
67-100%

127
Yes
67-100%

128
Yes
67-100%

129
Yes
67-100%

130
Yes
67-100%

131
Yes
67-100%

132
Yes
67-100%

133
Yes
34-66%

134
Yes
34-66%

135
Yes
34-66%

136
Yes
34-66%

137
Yes
34-66%

138
Yes
34-66%

139
Yes
34-66%

140
Yes
34-66%

[0138]

23

TABLE XIIa

Specimen
Tunneling
Visible

No.
Activity
Mortality

141
Yes
34-66%

142
Yes
67-100%

143
Yes
67-100%

144
Yes
34-66%

145
Yes
67-100%

146
Yes
67-100%

147
Yes
100%

148
Yes
67-100%

149
Yes
67-100%

150
Yes
67-100%

151
Yes
67-100%

152
Yes
67-100%

153
Yes
34-66%

154
Yes
34-66%

155
Yes
67-100%

156
Yes
67-100%

157
Yes
67-100%

158
Yes
67-100%

159
Yes
67-100%

160
Yes
67-100%

[0139]

24

TABLE XIIIa

Specimen
Tunneling
Visible

No.
Activity
Mortality

163
Yes
1-33%

165
Yes
1-33%

172
Yes
1-33%

174
Yes
1-33%

179
Yes
1-33%

[0140] From the results reported above the following conclusions can be reached. The test results for TBBA, TBBF and TBBS indicate a very significant effect in restricting termite damage to timber specimens treated with these actives.

[0141] TBBA, TBBF and TBBS all display significant termiticidal and termite repellent activity. Timber impregnated with these actives is protected against termite attack.

[0142] All the above description of preferred embodiments has been given for the purpose of illustration and is not meant to limit the invention. Many variations and modifications can be provided by the skilled person, all which are meant to be encompassed by the claims to follow.

Wood preservative compositions

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