People sometimes use the word "intimacy" as a euphemism for physical intimacy or sex. When a partner shows limited interest in being physically intimate, the reason for it is more likely to be emotional than strictly physical. Lack of emotional intimacy in the relationship can inhibit physical intimacy, too -- as can other emotional issues, such as depression or stress.
Intimacy of All Kinds
If you believe the stereotypes about men and women, men develop emotional intimacy through physical intimacy and women do the opposite. If this stereotype were accurate, men would always be interested in physical intimacy, regardless of the level of emotional intimacy in the relationship. However, for many men, interest in physical intimacy is more connected to emotional intimacy than a lot of people assume. If you and your husband haven't been able to make enough time for each other for a long time, he may be feeling emotionally disconnected. To encourage him to re-focus on the relationship, talk to him about how the two of you can spend more time together as a couple.
Depression and Mental Health
Lack of interest in sex and intimacy can be a sign of clinical depression, and other mental health issues can contribute to intimacy problems, too. If your husband experienced psychological trauma in his life, the pain and unresolved issues associated with his experiences could affect his ability to be close to you. If you suspect your husband's problems with intimacy are caused by a mental health issue, speak to him about seeking professional help.
If your husband is over 40, reduced testosterone levels could be the problem. Men often experience reduced testosterone starting around age 40, according to David McKenzie, a sex therapist interviewed by "Best Health" magazine. Low testosterone, erectile dysfunction or problems with premature ejaculation could make your husband feel self-conscious, causing him to avoid intimacy out of fear that it could lead to sex that he would have trouble performing. Although this can be difficult to discuss with your husband, the situation will not improve if you don't talk about it. A doctor might be able to help.
Stress and Alcohol
Stress from financial problems, child care obligations or pressure at work can all contribute to a reduced interest in physical intimacy. Stress could reduce your husband's energy levels so that he is too exhausted to focus on intimacy. If your husband deals with his stress by drinking alcohol when he gets home from work or after the kids are put to bed, alcohol can affect intimacy, too. If you suspect stress is the problem, talk to your husband about ways you could help him relax. If you think alcohol might be a contributing factor, talk to him about limiting his drinking.