Hot-melt pressure-sensitive adhesive for packaging and sealing contact lenses and preparation method of hot-melt pressure-sensitive adhesive

Abstract

The invention relates to the field of hot-melt pressure-sensitive adhesives, in particular to a hot-melt pressure-sensitive adhesive for packaging and sealing contact lenses and a preparation method of the hot-melt pressure-sensitive adhesive. The hot-melt pressure-sensitive adhesive is prepared from the following raw materials in parts by mass: 20 to 30 parts of styrene block copolymer, 50 to 60 parts of DCPD resin, 20 to 30 parts of plasticizer, 1 to 5 parts of hydrophilic agent and 0 to 3 parts of functional additive. In order to enable the hot-melt pressure-sensitive adhesive to be suitable for packaging and sealing of contact lenses, a specific hydrophilic agent is added into the preparation raw materials, so that the hot-melt pressure-sensitive adhesive has better hydrophilicity and excellent bonding performance, and the hot-melt pressure-sensitive adhesive is particularly suitable for packaging and sealing of the contact lenses.

Description

Technical Field

[0001] The invention relates to the field of hot melt pressure sensitive adhesives, in particular to a hot melt pressure sensitive adhesive for contact lens packaging and sealing and a preparation method thereof. Background Art

[0002] The correct use of contact lenses can effectively correct vision problems such as myopia, hyperopia, and astigmatism, allowing the wearer to clearly see the world around them. For many people with poor eyesight, contact lenses provide a more convenient and comfortable way to correct vision. Compared with traditional frame glasses, contact lenses do not affect appearance or cause inconvenience during exercise. When contact lenses are not in use, they are generally placed in a care solution. In order to increase the service life of the lenses, a suitable adhesive is needed to bond the outer packaging materials together to prevent the lenses from contacting the surrounding environment to keep the lenses sterile; however, this requires that the adhesive must be able to withstand the various uncertain environmental factors in the transportation environment, as well as the high temperature and humidity that may be encountered during use. At the same time, the adhesive must also be biocompatible and non-toxic to ensure the safety of the user.

[0003] At present, the mainstream contact lens packaging sealing on the market is mostly achieved by mechanical connection or adhesive connection method. The mechanical connection method may loosen or fall off during use. Due to the particularity of the storage environment of contact lenses, this requires the adhesive to have a certain hydrophilicity. Patent CN110655887B discloses a hot melt pressure-sensitive adhesive for repeatedly pasting wet wipes box cover sealing tape. The hot melt pressure-sensitive adhesive is also used in a wet environment and can achieve repeated bonding. However, the hot pressure-sensitive adhesive does not show hydrophilicity, so it is not suitable for contact lens packaging sealing. Therefore, the development of a high-performance, reliable, scalable, and hydrophilic adhesive for contact lens packaging sealing is an urgent need in the current industry. Summary of the invention

[0004] In order to solve the above technical problems, the first aspect of the present invention provides a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing. The raw materials for its preparation, calculated by weight, include: 20-30 parts of styrene-based block copolymer, 50-60 parts of DCPD resin, 20-30 parts of plasticizer, 1-5 parts of hydrophilic agent, and 0-3 parts of functional additive.

[0005] As an implementable case, the styrene block copolymer includes at least two of styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-butylene-styrene block copolymer (SEBS).

[0006] As an implementable case, the mass ratio of the styrene block copolymer and the DCPD resin is (20-25): (50-55).

[0007] As an implementable example, the styrene block copolymer includes SIS and SBS; the mass ratio of SIS to SBS is (10-20):(5-10).

[0008] As an implementable case, the mass fraction of styrene in the SIS is 15-30%, and the melt flow rate at 200° C. is 10-15 g / 10 min.

[0009] As an implementable case, the brand of SIS is selected from YH-1209, which can be purchased from Sinopec Baling Petrochemical Co., Ltd.; the mass fraction of styrene in YH-1209 is 29%, and the melt flow rate at 200°C is 12g / 10min.

[0010] As an implementable case, the mass fraction of styrene in the SBS is 30-35%, and the melt flow rate at 200° C. is 5-10 g / 10 min.

[0011] As an implementable case, the brand of SBS is selected from YH-188, which can be purchased from Sinopec Baling Petrochemical Co., Ltd.; the mass fraction of styrene in YH-188 is 32%, and the melt flow rate at 200°C is 6g / 10min.

[0012] In the present invention, SBS and SIS are preferably compounded, mainly because both SBS and SIS have good fluidity in the molten state, so the product is easy to process and mold, and the production efficiency is high; in addition, SIS has the characteristics of methyl side chains in its middle block polyisoprene structure, and has good cohesive strength and excellent adhesion performance. After compounding with SBS, the viscosity can be further enhanced, so that the final product has stronger adhesion ability. At the same time, SIS has a low modulus, small solution viscosity and melt viscosity, while SBS has relatively good weather resistance and water resistance. The compounding of the two can further improve the moisture resistance of the hot melt pressure-sensitive adhesive on the basis of ensuring that it has high bonding strength; therefore, the present invention preferably compounding SIS and SBS in a mass ratio of (10-20): (5-10). In the SBS molecule, the butadiene (B) segment mainly provides elasticity and flexibility, while the styrene (S) segment provides hardness and strength; when the styrene content is relatively high, the viscosity of the SBS will increase. The enhanced viscosity makes it easier for the SBS to form a firm adhesion interface with the adhered material during processing, but it will affect the moisture resistance of the product; in the SIS molecule, the isoprene segment has a lower glass transition temperature, which makes SIS have good flexibility and viscosity. When the S / I block ratio is relatively high, the content of the isoprene segment decreases, thereby improving the moisture resistance of the hot-melt pressure-sensitive adhesive; therefore, the inventors prefer to compound YH-188 with a high styrene content and YH-1209 with a high styrene content, which can ensure that the hot-melt pressure-sensitive adhesive has excellent moisture resistance while also having good bonding performance.

[0013] As an implementable case, the DCPD resin has a softening point of 120-130°C, a brand name of HY-6100, and is purchased from Henghe Materials Technology Co., Ltd.

[0014] The molecular structure of DCPD resin contains the alicyclic structure of dicyclopentadiene, which gives it low hygroscopicity and excellent heat resistance; while styrene block copolymers have a unique block molecular chain structure, which can hinder the penetration and diffusion of water to a certain extent; when the two are compounded, their molecular structures can complement each other to form a tighter network structure, thereby more effectively blocking the invasion of water; however, the softening point of DCPD resin needs to be further defined. Generally speaking, DCPD resin with a higher softening point has a stronger molecular chain rigidity and a greater interaction force between molecular chains, so the softening point of DCPD resin is relatively stable. The mobility of the sub-chain is poor, and it is more difficult to absorb and retain moisture in a humid environment, thereby improving the moisture resistance of the product; on the contrary, the DCPD resin with a lower softening point has a stronger molecular chain mobility and is more easily affected by moisture, resulting in poor moisture resistance. However, this does not mean that the higher the softening point of the DCPD resin, the better. When the softening point is too high, it has a relatively obvious negative impact on the processing performance of the product. Therefore, the present invention preferably uses a DCPD resin with a softening point of 120-130°C and a styrene-based block copolymer, which can further improve the moisture resistance of the product without affecting the bonding performance of the hot melt pressure-sensitive adhesive.

[0015] As an implementable example, the plasticizer includes: one of cycloalkane oil, aromatic oil or paraffin oil.

[0016] Furthermore, the plasticizer is cyclohexane oil, the softening point of cyclohexane oil is 70-90°C, the brand is KN4010, and it is purchased from Karamay Petrochemical Company.

[0017] As an implementable case, the hydrophilic agent includes one or more of glycerol, PEG (polyethylene glycol), and PPG (polypropylene glycol).

[0018] Furthermore, the hydrophilic agent is glycerol.

[0019] In order to make the hot-melt pressure-sensitive adhesive suitable for contact lens packaging and sealing, it is necessary to make the hot-melt pressure-sensitive adhesive have a certain hydrophilicity. In the present invention, a hydrophilic agent is added to the preparation raw materials. The hydrophilic groups in the hydrophilic agent can attract water molecules to prevent moisture from passing through the hot-melt pressure-sensitive adhesive and contaminating the contact lens. In addition, the hot-melt pressure-sensitive adhesive with good hydrophilicity can still maintain good adhesion performance in the humid environment of contact lens packaging and sealing.

[0020] As an implementable case, the functional additives include: one or more of antioxidants, anti-UV agents, thixotropic agents, flame retardants, antibacterial agents, pigments, antistatic agents, dispersants, lubricants, toughening agents, and photoinitiators; in the present invention, the functional additives can be reasonably selected according to the performance requirements of the actual product.

[0021] Furthermore, the functional auxiliary agent is an antioxidant.

[0022] As an implementable case, the antioxidant includes a hindered phenol antioxidant and / or a phosphite antioxidant; the hindered phenol antioxidant includes: one of antioxidant 1010 and antioxidant 1076; the phosphite antioxidant includes: one of antioxidant 168 and antioxidant 618.

[0023] Furthermore, the antioxidant is antioxidant 1010.

[0024] The second aspect of the present invention provides a method for preparing a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing, comprising:

[0025] S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive, and adding into a reaction kettle;

[0026] S2, heating to 150-180°C under stirring at 50-100 rpm, melting for 60-90 min;

[0027] S3, add a hydrophilic agent, cool to 120-140°C, and stir at a stirring speed of 25-40 rpm for 30-60 minutes under vacuum conditions.

[0028] Beneficial Effects

[0029] (i) The present invention uses a specific SIS and SBS compound as a styrene block copolymer, which can ensure that the hot melt pressure-sensitive adhesive has excellent bonding properties, and further limits the styrene content of SIS and SBS, which can ensure that the product has a certain moisture resistance.

[0030] (ii) The DCPD resin with a preferred softening point of 120-130° C. and the styrene-based block copolymer are compounded to further improve the moisture resistance of the hot melt pressure-sensitive adhesive without affecting the bonding performance of the hot melt pressure-sensitive adhesive.

[0031] (III) The amount of DCPD resin used in the present invention is significantly higher than that of the styrene-based block copolymer, which can ensure that the hot-melt pressure-sensitive adhesive has high toughness after use, but is not too rigid, and the product is more suitable for contact lens packaging and sealing.

[0032] (iv) In order to make the hot-melt pressure-sensitive adhesive suitable for contact lens packaging and sealing, a hydrophilic agent is added to the raw materials in the present invention. The hydrophilic groups in the hydrophilic agent can attract water molecules, so that the hot-melt pressure-sensitive adhesive has better hydrophilicity. The hot-melt pressure-sensitive adhesive with good hydrophilicity can still maintain good adhesion performance in the humid use environment of contact lens packaging and sealing.

[0033] (V) The raw materials for preparing the hot-melt pressure-sensitive adhesive provided by the present invention are from a wide range of sources, the cost is relatively low, no additional organic solvent is required during the preparation process, and the environmental performance is excellent; the raw materials only need to be added in a certain order of feeding, the preparation method is relatively simple, and the product is expected to achieve large-scale production. DETAILED DESCRIPTION

[0034] Example 1

[0035] The first aspect of this example provides a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing. The raw materials for its preparation, calculated by weight, include: 22 parts of styrene-based block copolymer, 52 parts of DCPD resin, 20.7 parts of plasticizer, 5 parts of hydrophilic agent, and 0.3 parts of functional additive.

[0036] The styrene block copolymer is SBS and SIS, and the mass ratio of SBS to SIS is 5:6; the brand of SBS is YH-188, purchased from Sinopec Baling Petrochemical Co., Ltd.; the brand of SIS is YH-1209, purchased from Sinopec Baling Petrochemical Co., Ltd.

[0037] The brand of the DCPD resin is HY-6100, which is purchased from Henghe Materials Technology Co., Ltd.

[0038] The plasticizer is cyclohexane oil with the brand name KN4010, purchased from Karamay Petrochemical Company.

[0039] The hydrophilic agent is glycerol, a common commercial product.

[0040] The functional additive is antioxidant 1010, a common commercial product.

[0041] The second aspect of this example provides a method for preparing a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing, comprising:

[0042] S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive, and adding into a reaction kettle;

[0043] S2, heating to 160°C with stirring at 70 rpm, melting for 60 min;

[0044] S3. Add a hydrophilic agent, cool to 140°C, and stir at a stirring speed of 40 rpm for 30 minutes under vacuum conditions.

[0045] Example 2

[0046] The first aspect of this example provides a hot melt pressure-sensitive adhesive, the raw materials for its preparation, calculated by weight, include: 24 parts of styrene block copolymer, 50 parts of DCPD resin, 20.7 parts of plasticizer, 5 parts of hydrophilic agent, and 0.3 parts of functional additive.

[0047] The styrene block copolymer is SBS and SIS, and the mass ratio of SBS to SIS is 1:2; the brand of SBS is YH-188, purchased from Sinopec Baling Petrochemical Co., Ltd.; the brand of SIS is YH-1209, purchased from Sinopec Baling Petrochemical Co., Ltd.

[0048] The brand of the DCPD resin is HY-6100, which is purchased from Henghe Materials Technology Co., Ltd.

[0049] The plasticizer is cyclohexane oil with the brand name KN4010, purchased from Karamay Petrochemical Company.

[0050] The hydrophilic agent is glycerol, a common commercial product.

[0051] The functional additive is antioxidant 1010, a common commercial product.

[0052] The second aspect of this example provides a method for preparing a hot melt pressure-sensitive adhesive, comprising:

[0053] S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive, and adding into a reaction kettle;

[0054] S2, heating to 160°C with stirring at 70 rpm, melting for 60 min;

[0055] S3. Add a hydrophilic agent, cool to 140°C, and stir at a stirring speed of 40 rpm for 30 minutes under vacuum conditions.

[0056] Comparative Example 1

[0057] The first aspect of this example provides a hot melt pressure-sensitive adhesive, the raw materials for its preparation, calculated by weight, include: 22 parts of styrene block copolymer, 52 parts of DCPD resin, 25.7 parts of plasticizer, and 0.3 parts of functional additive.

[0058] The styrene block copolymer is SBS and SIS, and the mass ratio of SBS to SIS is 5:6; the brand of SBS is YH-188, purchased from Sinopec Baling Petrochemical Co., Ltd.; the brand of SIS is YH-1209, purchased from Sinopec Baling Petrochemical Co., Ltd.

[0059] The brand of the DCPD resin is HY-6100, which is purchased from Henghe Materials Technology Co., Ltd.

[0060] The plasticizer is cyclohexane oil with the brand name KN4010, purchased from Karamay Petrochemical Company.

[0061] The functional additive is antioxidant 1010, a common commercial product.

[0062] The second aspect of this example provides a method for preparing a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing, comprising:

[0063] S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive, and adding into a reaction kettle;

[0064] S2, heating to 160°C under stirring at 70 rpm, melting for 60 min, to obtain.

[0065] Comparative Example 2

[0066] The first aspect of this example provides a hot-melt pressure-sensitive adhesive for contact lens packaging and sealing. The raw materials for its preparation include, by weight: 24 parts of styrene block copolymer, 53 parts of DCPD resin, 22.7 parts of plasticizer, and 0.3 parts of functional additive.

[0067] The styrene block copolymer is SBS and SIS, and the mass ratio of SBS to SIS is 1:2; the brand of SBS is YH-188, purchased from Sinopec Baling Petrochemical Co., Ltd.; the brand of SIS is YH-1209, purchased from Sinopec Baling Petrochemical Co., Ltd.

[0068] The brand of the DCPD resin is HY-6100, which is purchased from Henghe Materials Technology Co., Ltd.

[0069] The plasticizer is cyclohexane oil with the brand name KN4010, purchased from Karamay Petrochemical Company.

[0070] The functional additive is antioxidant 1010, a common commercial product.

[0071] The second aspect of this example provides a method for preparing a hot melt pressure-sensitive adhesive, comprising:

[0072] S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive, and adding into a reaction kettle;

[0073] S2, heating to 160°C under stirring at 70 rpm, melting for 60 min, to obtain.

[0074] Performance Evaluation

[0075] 1. Viscosity and softening point: The viscosity and softening point of the hot melt pressure-sensitive adhesives of Examples 1 to 2 and Comparative Examples 1 to 2 were tested according to HG / T 3660-1999 and GB / T 15332-1994 (ring and ball method) standards, respectively. The results are shown in Table 1.

[0076] Specifically, 100 g of the hot melt pressure-sensitive adhesives of Examples 1-2 and Comparative Examples 1-2 were placed in different beakers, and placed in an oven at 150° C., and the viscosity and softening point tests were performed after 12 h, 24 h, and 48 h.

[0077] Table 1

[0078]

[0079] 2. Peel strength: According to the test method standard of GB / T 2792-2014 adhesive tape peel strength, apply 20g / m between the release paper and the PRT film. 2 After the hot melt pressure sensitive adhesives of Examples 1 to 2 and Comparative Examples 1 to 2 were cured, the peel strength of the hot melt pressure sensitive adhesives of Examples 1 to 2 and Comparative Examples 1 to 2 was tested using a tensile testing machine. The results are shown in Table 2.

[0080] 3. Wet peel strength: According to the test method standard of GB / T 2792-2014 adhesive tape peel strength, apply 20g / m between the release paper and the PRT film. 2 After the hot melt pressure sensitive adhesives of Examples 1 to 2 and Comparative Examples 1 to 2 were cured, they were immersed in normal temperature water for 30 minutes and dried for 5 minutes, and then the wet peel strength of the hot melt pressure sensitive adhesives of Examples 1 to 2 and Comparative Examples 1 to 2 was tested using a tensile testing machine. The results are shown in Table 2.

[0081] 4. Peel strength after aging: According to the test method standard of GB / T 2792-2014 adhesive tape peel strength, apply 20g / m between the release paper and the PRT film. 2 After the hot melt pressure sensitive adhesive of Examples 1 to 2 and Comparative Examples 1 to 2 is cured, it is placed in an oven at 58°C and the viscosity is tested after 30 days. The peel strength of the hot melt pressure sensitive adhesive of Examples 1 to 2 and Comparative Examples 1 to 2 after aging is tested using a tensile testing machine. The results are shown in Table 2.

[0082] Table 2

[0083]

Claims

1. A hot melt pressure-sensitive adhesive for contact lens packaging and sealing, characterized in that: The raw materials for preparation include, by weight, 20-30 parts of styrene block copolymer, 50-60 parts of DCPD resin, 20-30 parts of plasticizer, 1-5 parts of hydrophilic agent, and 0-3 parts of functional additive.

2. The hot melt pressure-sensitive adhesive for contact lens packaging and sealing according to claim 1, characterized in that: The styrene block copolymer includes at least two of styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer and styrene-ethylene-butylene-styrene block copolymer.

3. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 2, characterized in that: The mass fraction of styrene in the styrene-isoprene-styrene block copolymer is 15-30%, and the melt flow rate at 200° C. is 10-15 g / 10 min.

4. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 2, characterized in that: The mass fraction of styrene in the styrene-butadiene-styrene block copolymer is 30-35%, and the melt flow rate at 200° C. is 5-10 g / 10 min.

5. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to any one of claims 1 to 4, characterized in that: The mass ratio of the styrene block copolymer to the DCPD resin is (20-25): (50-55).

6. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 1, characterized in that: The softening point of the DCPD resin is 120-130°C.

7. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 1, characterized in that: The plasticizer includes: one of naphthenic oil, aromatic oil or paraffin oil.

8. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 1, characterized in that: The hydrophilic agent includes one or more of glycerol, PEG, and PPG.

9. The hot melt pressure sensitive adhesive for contact lens packaging and sealing according to claim 1, characterized in that: The functional additives include: one or more of antioxidants, anti-UV agents, thixotropic agents, flame retardants, antibacterial agents, pigments, antistatic agents, dispersants, lubricants, toughening agents, and photoinitiators.

10. A method for preparing a hot melt pressure sensitive adhesive for contact lens packaging and sealing according to any one of claims 1 to 9, characterized in that: include: S1, mixing styrene block copolymer, DCPD resin, plasticizer and functional additive; S2, heating to 150-180°C under stirring at 50-100 rpm, melting for 60-90 min; S3, add a hydrophilic agent, cool to 120-140°C, and stir at a stirring speed of 25-40 rpm for 30-60 minutes under vacuum conditions.

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