How to Control Borate Efflorescence on Treated Surfaces

Overview of Technical Issues:

Environmental moisture penetrates the borate treatment layer and dissolves soluble borate salts, which then migrate to the surface and crystallize as efflorescence deposits when moisture evaporates; this harmful effect causes visible surface degradation and compromises the aesthetic and functional properties of the treated surface; the goal is to control or eliminate efflorescence formation while maintaining the protective benefits of the borate treatment.

Solution directions generated for this problem

Problem Direction 1 :

ImproveTreatment layer moisture barrier performance
VS
ConstraintManufacturing process complexity

Inspiration 1 : Cross-domain reference

Application Principle: #24 Intermediary
Cross-domain applicability Assess applicability
Column IV transistors for PMOS integration
Existing SolutionRefine solution

Vapor-deposited silox

Problem Direction 2 :

ImproveTreatment layer moisture barrier performance
VS
ConstraintTreatment protective effectiveness

Inspiration 1 : Cross-domain reference

Application Principle: #2 Taking out
Cross-domain applicability Assess applicability
Adhesive film and method for manufacturing organic electronic device using same
Innovative Solution Refine solution

Surface-only organosilane lock zone for borate-treated wood

Seal only the outer zone
How to solve :
  • After borate drying, spray 1.5–2.0 wt% alkyltrialkoxysilane in ethanol-water to wet only 0.3–0.8 mm surface depth, add 0.05 wt% acetic acid, cure 25–40°C for 4–6 h
  • Keep inner borate zone unchanged at >2 mm depth so fire, insect, and fungal protection remain active, target surface water contact angle ≥105° and capillary uptake reduction ≥80%
  • QC by FTIR Si-O-C peak, gravimetric pickup 8–15 g/m², depth check on dyed witness panels 0.3–0.8 mm, salt bloom test 40°C/95%RH 7 d with ≤5% visible area acceptance
Expected Effect : Efflorescence area −70 to −90%, boron retention +25 to +40%, WV uptake −60 to −80%, fire and bioprotection loss <5% vs untreated borate
Risk Control :
  • overpenetration blocks borate action
  • uneven silane pickup on end grain
  • poor cure under high wood moisture

Problem Direction 3 :

ImproveBorate salt migration resistance
VS
ConstraintTreatment protective effectiveness

Inspiration 1 : Cross-domain reference

Application Principle: #35 Parameter changes
Cross-domain applicability Assess applicability
Growth regulator concentrate and use thereof
Innovative Solution Refine solution

Depth-graded borate reservoir with low-surface-solubility zone

Shift borate inward
How to solve :
  • Impregnate with fine borate slurry, D50 1–5 μm, solids 25–35%, vacuum-pressure 0.8–1.0 MPa
  • Create depth gradient by brief surface rinse 5–15 s, removing top 0.2–0.5 mm soluble borate while keeping inner loading
  • Lock particles using silicate-borate matrix, sodium silicate 3–5% plus boric acid, cure 24 h at 25–40°C
Expected Effect : Surface efflorescence −70–90%, boron retention >85%, fungal rating 0–1, flame spread improvement 15–25% vs soluble-only borate
Risk Control :
  • particle agglomeration raises pore blocking
  • surface rinse over-removes active boron
  • silicate cure variation causes whitening

Problem Direction 4 :

ImproveTreatment layer moisture barrier performance
VS
ConstraintMust not deteriorate

Inspiration 1 : Cross-domain reference

Application Principle: #10 Preliminary action
Cross-domain applicability Assess applicability
Organic electronic device having dimension tolerance between encapsulating layer and metal-containing layer less than or equal to 200 microns
Innovative Solution Refine solution

Post-cure latent hydrophobe lock for borate-treated surfaces

Seal only after borate sets
How to solve :
  • Apply borate, dry 48–72 h to <12% MC
  • Spray alkyltrialkoxysilane 8–12 g/m², cure 24 h at 20–35°C
  • Verify contact angle >100°, uptake <0.20 kg/m², boron loss <5% by ICP
Expected Effect : Efflorescence −85%; water uptake −60%; boron retention >95%; fire/pest efficacy maintained; process add-on <36 h
Risk Control :
  • silane under-cure from high MC
  • uneven spray mass causing weak spots
  • alkaline surface reducing grafting yield
Patsnap Eureka Solution