• 한국가구학회지
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• 제11권2호
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• pp.73-78
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• 2000

This study was carried out to measure formaldehyde emission with the passing of two years from plywood, sliver-board and strand-board bonded with urea resins which were made of 6 f/U molar ratios. The urea resins were manufactured by six kinds of formaldehyde/urea molar ratio of 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0. 1. The plywood with molar ratio of 1.0 satisfied the KS F3101 $F_2$ directly after manufacture. The plywood with molar ratio of 1.2 satisfied m 3 days. The plywood with molar ratio of 1.4 satisfied the $F_3$ in 3 days and the $F_2$ in 600 days. And the plywood with molar ratio of 1.8 and 2.0 satisfied the $F_3$ in 365 days, but didn't satisfy the $F_2$ in 730 days. 2. Sliver-board with molar ratio of 1.0 and 1.2 satisfied the KS F3104 $E_2$ right after manufacture. Sliver-board with molar ratio of 1.4 and 1.6 satisfied in 150 and 360 days, respectively. Sliver-board with molar ratio of 1.8 and 2.0 satisfied in 730 days. 3. Strand-board with molar ratio of 1.0 and 1.2 satisfied the KS F3104$ E_2$ directly after manufacture. Strand-board with molar ratio of 1.4 and 1.6 satisfied in 150 days. But Strand-board with molar ratio of 1.8 and 2.0 didn't satisfied in 730 days.

• 폴리머
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• 제35권2호
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• pp.152-156
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• 2011

본 연구에서는 페닐아세테이트를 core 물질로 하고 poly(urea-formaldehyde)를 캡슐막 구성물질로 하는 미세캡슐의 제조에 있어서, 교반속도, core/shell 질량비, 계면활성제 농도, 반응시간 등의 고정변수가 캡슐의 크기, 막두께, 표면형태 등의 특성에 미치는 영향을 조사하였다. FTIR 및 TGA에 의하여 원하는 미세캡슐이 제조되었음을 확인하였다. 캡슐의 특성은 광학현미경과 FE-SEM을 사용허여 분석하였다. 교반속도의 증가에 따라 캡슐의 크기와 막두께가 감소하는 것으로 나타났다. 캡슐막 구성물질 질량의 증가는 캡슐막의 두께와 막표면에 부착되는 나노업자의 양을 증가시키는 것으로 나타났다. 계면활성제 농도의 증가에 의해 캡슐크기와 캡슐막 두께가 감소하는 것으로 확연되었다. 반응시간을 증가시키면 캡슐의 수율과 막두께가 증가하는 것이 관찰되었다.

• 한국잠사곤충학회지
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• 제20권1호
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• pp.15-23
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• 1978

본 연구는 견직물의 촉감을 손상시키지 않는 범위에서 바람직한 방추성을 보유하는 보다 좋은 요소수지가 공법을 개발하기 위하여 수년간에 걸친 보고이다. 특히 본보고는 요소와 결합하는 폴마린양을 극소화한데 특징이 있고 일반요소수지보다도 더욱 우수성을 보이는 반금속성요소수지(Homo Metalic Urea Resin)을 개발하였다는 사실도 첨가하며 본연구에서 얻어진 결과는 다음과 같다. 1. 본보고에 수록된 요소수지조성은 폴마린함량을 극소화하였고 조성된 수지에서 거의 폴마린냄새를 인정할 수 없을 정도였으며 이전에 보고된 어느 것보다 가장 소량의 폴마린으로 요소수지를 만들었다. 2. 필자가 최초로 만든 화합물 즉 uric zincchloride와 폴마린을 원료로 하여 새로운 반금속성요소수지(Homo Metalic Urea Resin)를 개발하였다. 이 방법은 합성수지처리와 중앙처리를 동시에 할 수 있는 특징이 있다. 3. 위의 두가지 수지처리에서 방추도, 강연도 및 발키네스 등이 증가되었는데 신규개발한 수지가 더욱 좋은 결과를 보였다. 4. 견방사나 저연사견직물이 생사나 고연사손직물의 경우보다 좋은 방추개선을 보였다. 5. 두가지 수지처리법이 모두 실용상의 경제성이 좋았다. 6. 강력과 신도가 수지처리후 다소 저하되었는데 이것은 수지처리로 가교작용과 증량작용이 일어났기 때문이었다. 7. 특수한 요소수지처리방법으로 양모와 유사한 견사제조법도 개발했다. 이 방법은 요소용액에 침지한 생사를 폴마린가스로 충만된 밀실에 방치해 둠으로서 생사표면에 스케일을 발생하게 한 것이다.

• Journal of the Korean Wood Science and Technology
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• 제1권2호
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• pp.11-15
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• 1973

This study was carried out to utilize sweet potato, and jerusalem artichoke flour as an extender of urea formaldehyde resin for plywood manufacture. The results obtained are summarized as follows: 1) In dry and wet test of plywood, sweet potato flour extended in urea formaldehyde resin was shown better strength than those of wheat flour. 2) Sweet potato flour was shown good results up to 200 percent extension in the dry test, and there was not shown significant difference between 100 percent and 150 percent extension in the wet test. 3) In the case of 100 percent extension, potato flour was shown best dry shear strength(400 psi) and sweet potato flour was shown best wet shear strength (212 psi).

• Journal of the Korean Wood Science and Technology
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• 제44권6호
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• pp.913-922
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• 2016

This study attempted to measure molecular weight (MW) of melamine-urea-formaldehyde (MUF) resins prepared by two different synthesis methods: the one-step MUF resins were synthesized in one batch procedure, while the two-step MUF resins were prepared by a physical mixing of urea-formaldehyde (UF) resin with melamine-formaldehyde (MF) resin that had been synthesized in a separate procedure. The properties of medium density fiberboard (MDF) panels bonded with two types of MUF resins were also investigated. MWs of these MUF resins were measured using gel permeation chromatography (GPC). In addition, this study measured the MWs of one-step MUF resin during its synthesis procedure. The performance of two types of MUF resins was evaluated by determining properties of MDF panels prepared in laboratory. As the synthesis procedure progressed, both number average MW ($M_n$) and weight average MW ($M_w$) of one-step MUF resin gradually increased, while the polydispersity index (PDI) decreased. And low Mw species of the resin predominantly decreased as the synthesis step progressed. The one-step MUF resin showed greater $M_n$ and $M_w$ than those of the two-step ones even though the PDI values of both resins were very similar each other. As expected, the one-step MUF resin resulted in better properties of MDF panels than those of two-step resins. In particular, the one-step MUF resin provided better internal bond (IB) strength and thickness swelling (TS) with MDF panels than those of two-step ones, indicating better water resistance of the one-step resin. These results suggest that the preparation method of MUF resins have a great impact on the MW and final panel properties.

• 한국산림과학회지
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• 제60권1호
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• pp.37-44
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• 1983

요소수지(尿素樹脂)의 변성제(變性劑)로서 열가망성(熱可望性)의 아세톤수지(樹脂)를 첨가(添加)하고 합판(合板)의 접착력(接着力) 및 목파율(木破率)에 미치는 영향(影響)을 조사(調査)하였다. 결론(結論)을 요약(要約)하면 다음과 같다. 1) 합판(合板)의 접착력(接着力)과 목파율(木破率)은 열판온도(熱板溫度) $120^{\circ}C$에서 제조한 것이 가장 좋은 값을 보였으나 아세톤수지(樹脂)의 혼합비율(混合比率)이 증가(增加)함에 따라서 그 값은 점차 감소(減少)되었다. 2) 아세톤수지(樹脂)의 몰비율(比率)은 합판(合板)의 접착력(接着力) 및 목파율(木破率)에 영향(影響)을 미치지 않았다. 3) 아세톤수지(樹脂)를 혼용(混用)한 합판(合板)은 요소수지(尿素樹脂)만으로 접착(接着)된 합판(合板)의 접착력(接着力) 및 목파율(木破率)을 능가하지 못했다. 따라서 아세톤수지(樹脂)는 요소수지(尿素樹脂)의 변성제(變性劑)는 부적당(不適當)하였다.

• Journal of the Korean Wood Science and Technology
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• 제16권3호
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• pp.5-16
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• 1988

This experiment was executed to investigate the effect of activation of veneer surface by oxidizing agents, hydrogen peroxide and nitric acid, on bonding characteristics of Malas(Homalium foetidum Benth) plywood, in which the effects of these oxidizing agents amount, pretreatment time, and pressing time and temperatue on shear strength of the plywood were examined and discussed. In this research the activation of veneer surface by oxidants was effective in raising shear strength but the difference in shear strength was not observed between hydrogen peroxide and nitric acid treatment. Hydrogen peroxide treatment, however, seemed to be more profitable to industrial application because of its lower concentration and easier handling than nitric acid. The bonding method by lignin-phenol adhesive through surface activation revealed inferior shear strength to phenol- and urea-formaldehyde adhesive but superior water resistance to urea-formaldehyde adhesive and this bonding method, in addition, have the advantage of lower cost compared with phenol-formaldehyde adhesive, Therefore, this bonding method by lignin-phenol adhesive through surface activation seemed to economical in manufacturing of water-resistant wood panel materials in future.

• 한국염색가공학회지
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• 제9권6호
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• pp.68-73
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• 1997

Urea/formaldehyde(UF) and melamine/formaldehyde(MF) microcapsules containing perfume and 2,4,4'-trichlroro-2-hydroxydiphenyl ether(DP) were prepared by the in-situ polymerization using urea and formaldehyde. Effects of dispersing agent, accelerating agent, formaldehyde, agitation speed on the mean diameter of microcapsules were investigated. The diameter of microcapsule was decreased with increasing dispersing agent concentration. A slight increase in the diameter was observed when the concentration of film forming material was increased. The diameter of microcapsule was decreased with increasing agitation speed up to 8,000rpm. The mean diameters of UF microcapsule prepared at 8,000rpm are about 3$\mu$m. A slight decrease in the diameter was observed when the concentration of resorcinol was increased.

• 한국의류학회지
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• 제10권2호
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• pp.59-67
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• 1986

To control the amounts of formaldehyde released from the cotton fabric finished with N-methylol compounds, glycerol was used as a formaldehyde-scavenging agent. It was observed the effects of catalysts and curing conditions when aftertreated with glycerol on melamine resin finished fabric. The effects of Different processes of glycerol treatment, and different resins, urea resin and melamine resin, were compared. The conclusions obtained from the results are as follows: 1) It was shown hatt the aftertreatment with glycerol (treated without catalyst) was more effective than treated with catalysts in controlling free formaldehyde. 2) The optimum curing temperature and curing time for the glycerol aftertreatment without adversely affecting the other properties of fabric was about $160^{\circ}C$, 3 min. 3) According to the increase of glycerol concentration in both aftertreatment and simultaneous treatment the amounts of free formaldehyde was reduced. The rate of decrease was manifest within the limits of $6\%$ in the case of simultaneous treatment with glycerol ana resins, and $3\%$ in the case of glycerol aftertreatment on resin finished fabrics. 4) Dry wrinkle recovery angle was decreased the increase of glycerol concentration. Melamine resin had a little adverse effect than urea resin, particulary glycerol aftertreatment. 5) The breaking strength was increased with the increase of glycerol concentration.

• Journal of the Korean Wood Science and Technology
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• 제29권4호
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• pp.33-39
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• 2001

포름알데히드와 요소의 몰비가 다른 2종류의 요소수지 접착제를 이용하여 접착제 첨가량과 열압시간 등 여러 조건에서 실험실 파티클보드를 열압하는 동안 배출되는 가스를 중류수에 용해 포집하고, 이렇게 얻어진 용액으로부터 포름알데히드 배출량을 미국 National Institute of Occupational Safety and Health (NIOSH) 3500의 방법에 의해 분석 비교하였다. 평가된 결과는 파티클보드를 열압하는 동안 배출되는 가스 중에서 포름알데히드량은 요소수지의 종류, 접착제 첨가량과 열압시간에 의해서 영향을 받는다는 것을 보여준다.